National
Survey
of
Lead
and
Allergens
in
Housing
Volume
I:
Analysis
of
Lead
Hazards
FINAL
REPORT
Revision
7.1
October
31,
2002
Prepared
for:

Office
of
Healthy
Homes
and
Lead
Hazard
Control
U.
S.
Department
of
Housing
and
Urban
Development
451
7th
Street,
N.
W.
Washington,
D.
C.
20410
Project
Officers:
Warren
Friedman,
Ph.
D.,
CIH
Joey
Zhou,
Ph.
D.

Prepared
by:

Westat,
Inc.
1650
Research
Boulevard
Rockville,
MD
20850
Robert
P.
Clickner,
Ph.
D.
David
Marker,
Ph.
D.
Susan
M.
Viet,
Ph.
D.,
CIH
John
Rogers
Pamela
Broene
This
work
was
conducted
under
HUD
Contract
Number
C­
OPC­
21356.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
i
Table
of
Contents
Chapter
Page
EXECUTIVE
SUMMARY
.................................................................................................................
ES­
1
1.
INTRODUCTION
.........................................................................................................
1­
1
1.1
Background........................................................................................................
1­
1
1.2
Survey
Objectives...............................................................................................
1­
3
1.2.1
Technical
Note
on
the
Survey
Weights....................................................
1­
4
1.3
Report
Organization
...........................................................................................
1­
4
2.
SURVEYED
HOUSING
POPULATION........................................................................
2­
1
3.
LEAD­
BASED
PAINT
(
LBP)
HAZARDS
IN
HOUSING
..............................................
3­
1
3.1
Definition
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards..................................
3­
1
3.2
Prevalence
of
Significant
Lead­
Based
Paint
Hazards
in
Housing..........................
3­
2
3.3
Prevalence
of
Lead­
Related
Occupations
or
Hobbies
.........................................
3­
11
4.
LEAD­
BASED
PAINT
(
LBP)
IN
HOUSING.................................................................
4­
1
4.1
Prevalence
of
Lead­
Based
Paint
.........................................................................
4­
1
4.2
Prevalence
of
Deteriorated
Lead­
Based
Paint
.....................................................
4­
8
4.3
Paint
Lead
Loadings
in
Housing........................................................................
4­
10
4.4
Comparison
of
Prevalence
of
Lead­
Based
Paint
(
LBP)
to
the
1990
LBP
Survey
.............................................................................
4­
14
4.5
Amount
of
Lead­
Based
Paint
in
Housing...........................................................
4­
17
5.
DUST
LEAD
IN
HOUSING...........................................................................................
5­
1
5.1
Prevalence
of
Dust
Lead
in
Housing....................................................................
5­
1
5.2
Dust
Lead
Loadings
in
Housing
..........................................................................
5­
3
5.3
Association
between
Interior
Dust
Lead
Hazards
and
Interior
LBP
Condition
....
5­
19
6.
RESIDENTIAL
SOIL
LEAD
.........................................................................................
6­
1
6.1
Prevalence
of
Residential
Soil
Lead
Over
All
Sampled
Locations.........................
6­
1
6.2
Association
Between
Soil
Lead
and
Exterior
Paint
Condition...............................
6­
6
6.3
Prevalence
of
Bare
Soil
Lead
in
Children's
Play
Areas
........................................
6­
8
6.4
Prevalence
of
Bare
Soil
Lead
in
the
Rest
of
the
Yard.........................................
6­
11
6.5
Comparison
of
Prevalence
of
Soil
Lead
to
the
1990
LBP
Survey
.......................
6­
13
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
ii
7.
QUALITY
OF
THE
NATIONAL
SURVEY
DATA
.......................................................
7­
1
7.1
Statistical
Concepts
and
Terminology
.................................................................
7­
1
7.2
Potential
for
Nonresponse
Bias
...........................................................................
7­
2
7.2.1
Analysis
of
Completion
and
Response
Rates...........................................
7­
2
7.2.2
Comparison
of
"
Hard
to­
Recruit"
Versus
"
Easy­
to­
Recruit"
HUs
....................................................................
7­
7
7.2.3
Completion
Rates
in
the
Play
Area
Subsample........................................
7­
8
7.3
Quality
of
Field
Data
Collection
and
Analysis
...................................................
7­
10
7.3.1
Field
Data
Collection
...........................................................................
7­
10
7.3.2
Laboratory
Quality
Control
Samples
....................................................
7­
13
7.3.3
Laboratory
Selection
Quality
Assurance...............................................
7­
14
7.4
Paint
Testing
Quality
Assurance
.......................................................................
7­
14
List
of
Appendices
APPENDIX
A
SELECTED
ADDITIONAL
TABLES
AND
FIGURES
..........................................
A­
1
APPENDIX
B
COMPARISON
OF
PROTOCOLS
FOR
THE
HUD
1990
SURVEY
OF
LEAD­
BASED
PAINT
(
LBP)
AND
THE
HUD
NATIONAL
SURVEY
OF
LEAD
AND
ALLERGIES
IN
HOUSING...................................
B­
1
APPENDIX
C
CORRECTING
FOR
CLASSIFICATION
BIAS
DUE
TO
MEASUREMENT
ERROR
............................................................................................................
C­
1
APPENDIX
D
CALCULATION
OF
SOIL
RELATED
ESTIMATES.............................................
D­
1
List
of
Tables
Table
ES.
1
Summary
Estimates
of
Prevalence
of
Lead­
Based
Paint
and
Lead­
Based
Paint
Hazards
........................................................................................................
ES­
2
Table
ES.
2
Type
of
Lead­
Based
Paint
Hazard
................................................................................
ES­
3
Table
2.1
Characteristics
of
the
Survey
Population,
with
Comparisons
to
the
American
Housing
Survey
(
AHS)
and
the
Current
Population
Survey
(
CPS)
.............................
2­
4
Table
3.1
Prevalence
of
Housing
Units
with
Significant
Lead­
Based
Paint
(
LBP)
Hazards,
by
Selected
Characteristics........................................................................................
3­
5
Table
3.2
Prevalence
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
by
Location
in
the
Building
..............................................................................................................
3­
8
Table
3.3
Prevalence
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
in
Housing
Units
with
a
Child
Under
6
years
of
Age
by
Type
of
Hazard...............................................
3­
9
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
iii
Table
3.4
Prevalence
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
in
Housing
Units
by
Type
of
Hazard
and
HU
Age...................................................................................
3­
10
Table
3.5
Prevalence
of
Housing
Units
with
Selected
Lead­
Related
Characteristics........................
3­
12
Table
3.6
Prevalence
of
Selected
Lead­
Related
Characteristics
in
Homes
with
Significant
Interior
LBP
Hazards
....................................................................................................
3­
12
Table
4.1
Prevalence
of
Lead­
Based
Paint
(
LBP)
by
Selected
Housing
Unit
(
HU)
Characteristics..........................................................................................................
4­
4
Table
4.2
Prevalence
of
Lead­
Based
Paint
(
LBP)
by
Location
in
the
Building..................................
4­
7
Table
4.3
Prevalence
of
Deteriorated
and
Significantly
Deteriorated
Lead­
Based
Paint
(
LBP)
by
Location
in
the
Building.............................................................................
4­
8
Table
4.4
Distribution
of
Housing
Units
(
HUs)
with
Deteriorated
and
Significantly
Deteriorated
Lead­
Based
Paint
(
LBP)
by
Construction
Year
......................................
4­
9
Table
4.5
Distribution
of
Paint
Lead
Loading
by
Location
in
the
Building
.....................................
4­
11
Table
4.6
Distribution
of
Paint
Lead
Loading
by
Location
in
the
Building
and
Construction
Year...................................................................................................
4­
12
Table
4.7
Estimated
Empirical
Distribution
Parameters
of
Paint
Lead
Loadings
by
Interior
Component
Types.......................................................................................
4­
13
Table
4.8
Estimated
Empirical
Distribution
Parameters
of
Paint
Lead
Loadings
by
Exterior
Component
Types......................................................................................
4­
13
Table
4.9
Percentage
of
Components
with
Lead­
Based
Paint
by
Component
Type
And
HU
Age...........................................................................................................
4­
14
Table
4.10
Estimated
Empirical
Distribution
Parameters
of
Paint
Lead
Loadings
by
Room
Type.......................................................................................................................
4­
14
Table
4.11
Comparison
of
the
Prevalence
of
Lead­
Based
Paint
to
the
1990
LBP
Survey..................
4­
15
Table
4.12
Amount
of
LBP
by
Painted
Component
.........................................................................
4­
18
Table
5.1
Prevalence
of
Housing
Units
with
a
Dust
Lead
Hazard
Somewhere
in
the
Home...............
5­
2
Table
5.2
Distribution
of
Maximum
Dust
Lead
Loadings
in
Housing
Units
by
Surface
....................
5­
5
Table
5.3
Distribution
of
Average
Dust
Lead
Loadings
in
Housing
Units
by
Surface
.......................
5­
7
Table
5.4
Distribution
of
Dust
Lead
Loading
by
Room
and
Surfaces...............................................
5­
9
Table
5.5a
Maximum
Floor
Dust
Lead
Loading
by
Year
of
Construction
........................................
5­
11
Table
5.5b
Maximum
Window
Sill
Dust
Lead
Loading
by
Year
of
Construction
.............................
5­
12
Table
5.5c
Maximum
Window
Trough
Dust
Lead
Loading
by
Year
of
Construction
.......................
5­
13
Table
5.6a
Maximum
Floor
Dust
Lead
Loadings
by
Household
Income
..........................................
5­
14
Table
5.6b
Maximum
Window
Sill
Lead
Dust
Loadings
by
Household
Income................................
5­
15
Table
5.6c
Maximum
Window
Trough
Lead
Dust
Loadings
by
Household
Income..........................
5­
19
Table
5.7
Estimated
Empirical
Distribution
Parameters
of
Dust
Lead
Loadings
by
Surface
Types.........................................................................................................
5­
19
Table
5.8
Association
Between
Dust
Lead
Hazards
and
Presence
and
Condition
of
Interior
Lead­
Based
Paint........................................................................................
5­
20
Table
5.9
Association
Between
Floor
Dust
Lead
Loadings
and
Presence
of
Interior
Lead­
Based
Paint....................................................................................................
5­
21
Table
5.10
Association
Between
Window
Sill
Dust
Lead
Loadings
and
Presence
of
Interior
Lead­
Based
Paint....................................................................................................
5­
22
Table
6.1
Distribution
of
Maximum
Bare
Soil
Sample
Lead
Concentrations
(
All
Sampled
Locations)
................................................................................................................
6­
3
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
iv
Table
6.2
Distribution
of
Maximum
Bare
Soil
Sample
Lead
Concentrations
(
All
Sampled
Locations)
................................................................................................................
6­
4
Table
6.3
Estimated
Empirical
Distribution
Parameters
of
Soil
Lead
Concentrations
by
Sample
Site
..............................................................................................................
6­
6
Table
6.4
Association
Between
Bare
Soil
Lead
Concentration
and
Presence
of
Significantly
Deteriorated
Exterior
LBP,
All
Sampled
Locations................................
6­
7
Table
6.5
Distribution
of
Maximum
Soil
Lead
Concentrations
in
Children's
Play
Areas
..................
6­
9
Table
6.6
Distribution
of
Maximum
Soil
Lead
Concentration
in
Children's
Play
Areas,
by
Construction
Year
..............................................................................................
6­
10
Table
6.7
Association
Between
Bare
Soil
Lead
Concentration
and
Presence
of
Significantly
Deteriorated
Exterior
LBP,
in
Children's
Play
Areas
...........................
6­
11
Table
6.8
Distribution
of
Maximum
Bare
Soil
Lead
Concentrations
in
the
Rest
of
the
Yard......................................................................................................
6­
12
Table
6.9
Distribution
of
Maximum
Bare
Soil
Lead
Concentrations
in
the
Rest
of
the
Yard,
by
Construction
Year
....................................................................................
6­
13
Table
6.10
Comparison
of
the
Prevalence
of
Lead­
Contaminated
Bare
Soil
in
the
National
Survey
and
the
1990
LBP
Survey..............................................................
6­
14
Table
7.1
Completion
Rates
by
1990
Census
Block
Group
Characteristics
......................................
7­
6
Table
7.2
Mean
Percents
for
Completed
and
Noncompleted
Housing
Units
by
1990
Census
Block
Group
Characteristics
.........................................................................
7­
7
Table
7.3
Comparison
of
"
Easy­
to­
Recruit"
Respondents
Versus
"
Hard­
to­
Recruit"
Respondents
by
Reported
Housing
Characteristics.....................................................
7­
8
Table
7.4
Completions
in
Play
Area
Subsample
............................................................................
7­
10
List
of
Figures
Figure
3.1
Prevalence
of
Housing
Units
(
HUs)
with
Significant
LBP
Hazards...................................
3­
4
Figure
4.1
Prevalence
of
Lead­
Based
Paint
by
Selected
Housing
Unit
Characteristics
.......................
4­
2
Figure
4.2
Prevalence
of
HUs
with
LBP
by
Construction
Year
&
Presence
of
Children
<
6...............
4­
3
Figure
4.3
Prevalence
of
Lead­
Based
Paint
by
Location
in
the
Building
............................................
4­
7
Figure
4.4
Presence
and
Condition
of
LBP
by
Construction
Year....................................................
4­
10
Figure
5.1
Dust
Lead
Hazards
by
Construction
Year
........................................................................
5­
2
Figure
5.2
Dust
Lead
Hazards
by
Household
Income........................................................................
5­
3
Figure
5.3
Distribution
of
Maximum
Floor
Dust
Lead
Loadings
.......................................................
5­
4
Figure
5.4
Distribution
of
Maximum
Window
Sill
Dust
Lead
Loadings
............................................
5­
4
Figure
5.5
Association
Between
Dust
Lead
Loading
on
Floors
and
Window
Sills
............................
5­
10
Figure
5.6
Box
Plots
for
Dust
Lead
Loadings
by
Room..................................................................
5­
17
Figure
5.7
Box
Plots
for
Dust
Lead
Loadings
by
Surface
...............................................................
5­
18
Figure
5.8
Association
Between
Dust
Lead
Hazards
and
Condition
of
Interior
Lead­
Based
Paint....................................................................................................
5­
20
Figure
6.1
Distribution
of
Maximum
Bare
Soil
Lead
Concentrations
................................................
6­
2
Figure
6.2
Box
Plots
for
Lead
in
Soil
Samples
by
Sample
Site..........................................................
6­
5
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
v
Figure
6.3
Association
Between
Lead
in
Bare
Soil
and
Significantly
Deteriorated
Exterior
Lead­
Based
Paint......................................................................................................
6­
8
Figure
6.4
Distribution
of
Maximum
Bare
Play
Area
Soil
Lead
Concentrations
................................
6­
9
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
vi
EXECUTIVE
SUMMARY
The
National
Survey
of
Lead
and
Allergens
in
Housing
(
NSLAH)
was
conducted
under
the
sponsorship
of
the
Department
of
Housing
and
Urban
Development
(
HUD)
and
the
National
Institute
of
Environmental
Health
Sciences
(
NIEHS)
to
assess
children's
potential
household
exposure
to
lead
and
allergens.
The
NSLAH
measured
the
levels
of
lead
in
dust,
soil,
and
paint,
the
prevalence
of
hazardous
levels
of
lead,
and
levels
and
patterns
of
various
indoor
allergens
in
dust
in
homes.
Volume
I
includes
the
findings
for
lead
hazards,
and
describes
lead
levels
in
dust,
soil,
and
paint
in
the
nation's
housing
by
age,
type,

geographical
location,
and
exposed
populations.
This
Executive
Summary
refers
to
the
standards
of
HUD's
"
Lead
Safe
Housing
Rule"
(
24
CFR
35
Subparts
B­
R)
1
on
Federally­
owned
and
­
assisted
housing
with
thresholds
from
the
EPA
"
Rule:
Identification
of
Dangerous
Levels
of
Lead"
(
40
CFR
Part
745)
2.

Results:
Extent
of
Lead­
Based
Paint
and
Lead­
Based
Paint
Hazards
in
Housing
An
estimated
38
million3
homes
(
40
percent
of
all
homes)
in
the
United
States
have
lead­
based
paint
somewhere
in
the
building.
Of
these,
20
million
homes
have
lead­
based
paint
present
on
both
interior
and
exterior
surfaces,
9
million
homes
have
lead­
based
paint
only
on
the
interior,
and
another
9
million
homes
have
lead­
based
paint
only
on
the
exterior.

Although
a
large
number
of
homes
have
lead­
based
paint,
most
of
them
have
relatively
small
surface
areas
of
it.
The
average
home
with
lead­
based
paint
has
an
estimated
259
square
feet
of
interior
leadbased
paint
and
996
square
feet
of
exterior
lead­
based
paint.
For
comparison,
a
room
10
feet
by
12
feet
with
an
8
foot
ceiling
has
a
wall
area
of
352
square
feet.

An
estimated
24
million
(
26
percent)
homes
have
significant
lead­
based
paint
hazards
somewhere
in
the
building
or
on
the
premises;
this
is
consistent
with
earlier
HUD
estimates
of
24
million
homes.
4
Based
on
the
HUD
Lead
Safe
Housing
Rule,
a
home
is
said
here
to
have
a
significant
lead­
based
paint
hazard
if
one
1
Title
24
of
the
Code
of
Federal
Regulations,
Part
35
was
issued
September
15,
1999
in
Volume
64
of
the
Federal
Register,
pages
50140­
50231,
and
became
effective
September
15,
2000.
It
implemented
sections
1012
and
1013
of
the
Residential
Lead­
Based
Paint
Hazard
Reduction
Act
of
1992,
which
is
Title
X
of
the
Housing
and
Community
Development
Act
of
1992
(
P.
L.
102­
550).
A
copy
is
available
on
the
Internet
at
www.
hud.
gov/
offices/
lead.

2
Issued
January
5,
2001
in
Volume
66
of
the
Federal
Register,
pages
1206­
1240,
and
became
effective
on
March
6,
2001.

3
The
95
percent
confidence
intervals
for
the
estimates
are
presented
in
the
main
body
of
the
report.

4
President's
Task
Force
on
Environmental
Health
Risks
and
Safety
Risks
to
Children,
2000.
Eliminating
Childhood
Lead
Poisoning:
A
Federal
Strategy
Targeting
Lead­
Based
Paint
Hazards
(
Report
and
Appendix).
Washington,
D.
C.:
U.
S.
Department
of
Housing
and
Urban
Development
and
U.
S.
Environmental
Protection
Agency.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
vii
or
more
of
the
following
conditions
exists:
lead­
based
paint
with
deterioration
larger
than
de
minimis
levels
specified
in
the
Lead
Safe
Housing
Rule,
5
dust
lead
loadings
at
or
above
specified
thresholds
on
floors
or
window
sills;
6
bare
soil
in
children's
play
areas
above
specified
thresholds;
or
more
than
9
square
feet
of
bare
soil
in
the
rest
of
the
yard
with
lead
concentrations
at
or
above
specified
thresholds.
7
Of
the
16.4
million
homes
with
one
or
more
children
under
age
6,
an
estimated
4.2
million
(
25
percent)
have
significant
lead­
based
paint
hazards.
Of
all
4.8
million
homes
with
household
incomes
under
$
30,000
and
one
or
more
children
under
age
6,
an
estimated
1.2
million
(
25
percent)
have
significant
leadbased
paint
hazards.
Thus,
one
in
four
homes
with
young
children
among
the
residents
have
significant
leadbased
paint
hazards.
Table
ES.
1
summarizes
these
basic
estimates
of
the
prevalence
of
lead­
based
paint
and
significant
lead­
based
paint
hazards.

Table
ES.
1
Summary
Estimates
of
Prevalence
of
Lead­
Based
Paint
and
Lead­
Based
Paint
Hazards
Housing
Unit
Characteristica
Number
of
Housing
Units
(
millions)
Number
of
Housing
Units
with
Lead­
Based
Paint
(
millions)
Number
of
Housing
Units
with
Significant
Lead­
Based
Paint
hazards
(
millions)
Total
housing
units
95.7
37.9
24.0
One
or
more
children
under
age
6
16.4
5.3
4.2
One
or
more
children
under
age
6,
less
than
$
30,000/
year
household
income
4.8
1.4
1.2
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.

5
The
de
minimis
levels
for
LBP
deterioration
are
in
Section
35.1350(
d)
of
the
Lead
Safe
Housing
Rule.
These
levels
are:
deterioration
of
more
than
20
square
feet
(
exterior)
or
2
square
feet
(
interior)
of
LBP
on
large
surface
area
components
(
walls,
doors)
or
deterioration
of
more
than
10%
of
the
total
surface
area
of
interior
small
surface
area
components
types
(
window
sills,
baseboards,
trim).
These
are
the
same
levels
used
in
the
U.
S.
Environmental
Protection
Agency's
lead
hazard
standards
rule
implementing
the
Toxic
Substance
Control
Act's
Section
403.

6
The
floor
and
window
sill
dust
lead
loading
thresholds
are
dust
on
floors
with
greater
than
or
equal
to
40
µ
g/
ft2
lead
and
dust
on
window
sills
with
greater
than
or
equal
to
250
µ
g/
ft2
lead.
They
are
in
the
HUD
Lead
Safe
Housing
rule
and
in
the
EPA
Rule
Identification
of
Dangerous
Levels
of
Lead;
40
CFR
Part
745,
January
5,
2001.

7
The
thresholds
for
bare,
lead­
contaminated
soil
are
more
than
9
square
feet
of
bare
soil
with
a
lead
concentration
greater
than
or
equal
to
1,200
ppm
lead,
or
400
ppm
for
bare
soil
in
an
area
frequented
by
a
child
under
the
age
of
6
years.
These
thresholds
are
in
the
HUD
Lead
Safe
Housing
Rule.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
viii
Of
the
24
million
homes
with
significant
lead­
based
paint
hazards,
an
estimated
15
million
have
interior
dust
lead
hazards,
14
million
have
deteriorated
lead­
based
paint
at
or
above
de
minimis
levels
and
6
million
have
soil
lead
hazards,
as
displayed
in
Table
ES.
2.

Table
ES.
2
Type
of
Lead­
Based
Paint
Hazard
Number
of
Housing
Units
(
millions)
Percentage
of
Housing
Unitsa
Type
of
Hazard
Estimate
95%
CIb
Estimate
95%
CI
Significantly
Deteriorated
lead­
based
paint
13.63
10.9
 
16.3
14
11­
17
Interior
lead­
contaminated
dust
15.47
13.0
 
18.0
16
14­
19
Lead­
contaminated
soil
6.46
3.1
 
9.8
7
3­
10
Any
lead­
based
paint
hazard
24.03
21.3
 
26.7
25
22­
28
a
All
percentages
are
calculated
with
total
housing
units
(
95,688,000)
as
the
denominator;
percentages
may
not
total
100%
due
to
rounding.

b
95%
CI
=
95
percent
confidence
interval.

Dust
lead
levels
above
the
Lead
Safe
Housing
Rule's
standards
are
associated
with
the
presence
of
interior
lead­
based
paint.
An
estimated
29
million
homes
have
some
interior
lead­
based
paint,
of
which
39
percent
have
dust
lead
levels
above
the
Lead
Safe
Housing
Rule's
standards.
In
contrast,
only
6
percent
of
the
67
million
homes
without
interior
lead­
based
paint
have
dust
levels
above
the
Lead
Safe
Housing
Rule's
standards.

Soil
lead
levels
above
the
Lead
Safe
Housing
Rule's
standards
are
associated
with
the
presence
of
deteriorated
exterior
lead­
based
paint.
Homes
with
deteriorated
exterior
lead­
based
paint
above
de
minimis
levels
are
six
times
more
likely
to
have
soil
lead
hazards
than
are
homes
free
of
such
deteriorated
lead­
based
paint.

This
most
recent
HUD
survey
shows
that
the
number
of
housing
units
with
lead­
based
paint
has
declined
from
64
million
in
1990
to
38
million
ten
years
later.
On
the
other
hand,
the
prevalence
of
homes
with
deteriorating
lead­
based
paint
increased
slightly,
from
19%
to
22%.

Survey
Design
and
Methodology
The
principal
lead­
related
purpose
of
the
NSLAH
was
to
develop
a
scientific
description
of
the
existing
lead
levels
in
paint,
dust,
and
soil
in
the
nation's
housing.
Additional
objectives
were
to
obtain
data
to:
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
ix
(
1)
estimate
the
number
and
percent
of
homes
with
dust
and
soil
lead
levels
above
selected
thresholds;
(
2)

identify
sources
of
lead
in
dust
in
housing,
e.
g.,
paint
and
soil;
(
3)
permit
future
analyses
of
lead
hazard
control
strategies
and
costs,
e.
g.,
quantities
of
deteriorated
painted
surfaces;
and
(
4)
permit
future
analyses
for
regulation,
policy,
and
guidance
that
minimize
regulatory
and
program
implementation
burden.

The
target
population
included
approximately
96
million
homes,
of
the
112
million
total
homes
in
the
nation,
including
single­
and
multi­
family
buildings
and
manufactured
housing
units,
e.
g.,
mobile
homes
and
trailers.
Homes
built
in
all
age
categories
were
included.
Vacant
housing,
group
quarters,
and
hotels
and
motels
were
excluded
for
reasons
of
difficulties
gaining
cooperation.
Housing
where
children
were
not
permitted
to
live,
e.
g.,
elderly
care
facilities,
were
excluded
because
the
primary
interest
was
in
children's
exposure
to
lead.
Thus,
16
million
units
out
of
112
million
total
units
were
excluded
from
this
survey.

The
main
field
survey
was
conducted
in
1998­
1999,
with
an
augmentation
of
the
soil
sampling
in
2000
to
include
additional
play
area
samples.
A
nationally­
representative
sample
of
1,984
homes
was
drawn
from
75
clusters
(
each
a
metropolitan
statistical
area
(
MSA)
or
a
group
of
counties
that
have
a
minimum
population
of
15,000)
called
primary
sampling
units
(
PSUs).
A
total
of
831
eligible
homes
were
recruited
and
completed
the
survey.

Four
rooms
were
randomly
selected
for
environmental
sample
collection
and
testing
from
each
of
four
room
types:
kitchen,
common
living
areas,
bedrooms
(
preferably
those
occupied
by
children),
and
other
rooms.
In
each
of
these
four
rooms
floor,
window
sill,
and
window
trough
dust
samples
were
collected,

painted
surfaces
were
measured
for
lead
content,
and
the
condition
of
painted
surfaces
was
assessed.
Outside
the
building,
soil
samples
were
taken
and
exterior
painted
surfaces
were
tested.
A
floor
dust
sample
was
collected
in
the
interior
common
area
of
multi­
family
buildings.

Measurements
of
lead
in
paint
were
made
by
State­
or
EPA­
certified
lead­
based
paint
inspectors
using
an
XRF
analyzer
and
a
protocol
based
on
HUD's
1997
Guidelines'
inspection
procedure.
8
The
instrument
model
used
does
not
require
making
substrate
corrections,
nor
have
an
inconclusive
range,
both
of
which
involve
destructive
sampling
of
painted
surfaces.
One
XRF
reading
was
made
per
painted
component
in
each
room,
approximately
in
the
center
of
a
randomly
selected
quadrant
of
the
total
building
component
surface
area.

8
HUD
1539­
LBP.
Guidelines
for
the
Evaluation
and
Control
of
Lead­
Based
Paint
Hazards
in
Housing,
Chapter
7.
U.
S.
Department
of
Housing
and
Urban
Development,
Washington,
D.
C.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
ES­
x
Single
wipe
dust
samples
were
collected
by
the
technique
described
in
ASTM
E
1728­
95.9
Floor
dust
samples
were
collected
in
the
center
of
the
largest
open
floor
area
in
the
room.
The
floor
samples
in
the
major
entrance
and
interior
common
area
were
collected
approximately
six
inches
away
from
the
center
of
the
doorway.
One­
square­
foot
templates
were
used
for
floor
samples.
Window
sill
and
trough
samples
were
collected
from
a
random,
openable
window
in
each
selected
room.
The
entire
area
was
wiped
for
window
sill
and
trough
samples
(
up
to
two
square
feet).
All
dust
samples
were
analyzed
by
flame
atomic
absorption
spectrophotometry,
using
the
Environmental
Protection
Agency's
(
EPA's)
SW­
846
method
3050
digestion
method
and
the
American
Industrial
Hygiene
Association's
Environmental
Lead
Laboratory
Accreditation
Program
(
ELLAP)
proficiency
testing
procedures.
The
laboratory
that
performed
the
analysis
was
NLLAP
 

recognized
for
dust
lead
analyses.

Soil
sampling
was
conducted
in
accordance
with
core
sampling
procedures
described
in
ASTM
E
1727­
95.10
Only
the
top
one­
half
inch
of
each
soil
core,
i.
e.,
that
portion
most
accessible
to
children,
was
included
in
the
sample.
Where
necessary,
grass
or
leaf
covering
was
gently
removed
before
taking
the
core.

Soil
samples
were
taken
outside
the
building
at
the
major
entrance,
and
along
the
dripline
and
mid­
yard
area
of
two
sides
of
the
building.
Soil
samples
were
collected
from
children's
play
areas
in
a
subsample
of
375
homes.
Soil
samples
were
analyzed
by
inductively­
coupled
plasma
atomic
emission
spectroscopy,
using
the
SW­
846
digestion
method
and
the
ELLAP
proficiency
testing
procedures.
The
laboratory
that
performed
the
analysis
was
NLLAP
 
recognized
for
dust
lead
analyses.

9
ASTM
E
1728­
95.
(
1995b).
Standard
practice
for
the
field
collection
of
settled
dust
samples
using
wipe
sampling
methods
for
lead
determination
by
atomic
spectrometry
techniques.
American
Society
for
Testing
and
Materials,
West
Conshohocken,
PA.

10
ASTM
E
1727­
95.
Standard
practice
for
the
field
collection
of
soil
samples
for
lead
determination
by
atomic
spectrometry
techniques.
American
Society
for
Testing
Materials,
West
Conshohocken,
PA.
1.
INTRODUCTION
The
National
Survey
of
Lead
and
Allergens
in
Housing
(
NSLAH)
was
conducted
under
the
sponsorship
of
the
Department
of
Housing
and
Urban
Development
(
HUD)
and
the
National
Institute
of
Environmental
Health
Sciences
(
NIEHS)
to
assess
children's
potential
household
exposure
to
lead
and
allergens,
i.
e.,
to
estimate
the
levels
of
lead
in
dust,
soil,
and
paint,
the
prevalence
of
hazardous
levels
of
lead,
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
1­
2
October
31,
2002
and
levels
and
patterns
of
various
indoor
allergens
(
allergy­
inducing
substances)
in
dust
in
homes.
Combining
the
goals
of
HUD
and
NIEHS
into
a
single
survey
saved
significant
public
funds,
reduced
the
survey
response
burden
on
the
public,
and
substantially
reduced
the
time
required
to
obtain
the
data
needed
by
both
agencies
for
their
ongoing
primary
and
secondary
prevention
activities.

This
report,
Volume
I,
includes
the
findings
for
lead
hazards,
and
describes
lead
levels
in
dust,

soil,
and
paint
in
the
nation's
housing
by
age,
type,
geographical
location,
and
exposed
populations.
In
addition,
the
report
estimates
the
number
and
percent
of
homes
with
dust
and
soil
lead
levels
above
selected
thresholds,
especially
thresholds
in
HUD's
Lead
Safe
Housing
Rule
(
24
CFR
Part
35
Subparts
B­
R,

Requirements
for
Notification,
Evaluation
and
Reduction
of
Lead­
Based
Paint
Hazards
in
Federally
Owned
Residential
Property
and
Housing
Receiving
Federal
Assistance,
effective
September
15,
2000),
and
EPA's
Final
Rule:
Identification
of
Dangerous
Levels
of
Lead
(
40
CFR
745),
effective
March
6,
2001.

1.1
Background
Lead
is
a
toxin
that
affects
the
central
nervous
system
and
is
particularly
damaging
to
the
developing
nervous
system
of
young
children
and
fetuses.
High
blood
lead
levels
can
result
in
convulsions,

mental
retardation,
and
even
death.
Research
has
shown
that
even
low
lead
levels
can
have
serious
health
consequences.
These
include
reduced
intelligence
and
short­
term
memory,
slower
reaction
times,
poorer
handeye
coordination,
reduced
height,
hearing
problems,
and
numerous
behavioral
problems.
11
Although
there
are
many
sources
of
lead
in
the
environment,
including
drinking
water,
food,

emissions
from
gasoline
combustion,
and
industrial
emissions,
it
is
clear
that
lead­
based
paint
(
LBP)
plays
a
major
role
in
high
blood
lead
levels
among
children
today.
Research
indicates
that
dust
and
soil
are
the
most
significant
pathways
for
children's
lead
exposure,
and
that
LBP
is
the
major
important
source
of
household
dust
lead.
12,13
The
fundamental
purpose
of
the
Residential
Lead­
Based
Paint
Hazard
Reduction
Act
of
1992,

which
is
Title
X
of
the
Housing
and
Community
Development
Act
of
1992
(
P.
L.
102­
550)
is
prevention,
i.
e.,

11
National
Academy
of
Sciences
(
1993).
Measuring
lead
exposure
in
infants,
children,
and
other
sensitive
populations.
National
Academy
Press,
Washington,
DC.

12
Bornschein,
R.,
Hammond,
P.
B.,
Dietrich,
et
al.
(
1985a).
The
Cincinnati
prospective
study
of
low­
level
lead
exposure
and
its
effects
on
child
development:
Protocol
and
status
report.
Environ.
Res.
38:
4­
18.

13
Bornschein,
R.,
Succop,
P.,
Dietrich,
et
al.
(
1985b).
The
influence
of
social
and
environmental
factors
on
dust
lead,
hand
lead,
and
blood
lead
levels
in
young
children.
Environ.
Res.
38:
108­
118.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
1­
3
October
31,
2002
to
find
and
mitigate
LBP
hazards
in
homes
before
children
are
poisoned.
In
Sections
1051
and
1052(
10),

Congress
required
HUD
to
conduct
research
on
risk
reduction
strategies
from
household­
based
lead
exposure,

and
to
assess
the
effectiveness
of
lead
hazard
evaluation
activities,
respectively.
The
NSLAH
was
undertaken
to
provide
current
information
needed
for
regulatory
and
policy
decisions
and
for
assessment
of
the
effectiveness
of
lead
hazard
reduction
strategies,
e.
g.,
lead
information
disclosure
during
housing
sale
or
lease
transactions
and
certification
of
LBP
professionals.

In
1989­
1990,
HUD
sponsored
a
national
survey
of
LBP
in
housing
(
referred
to
as
the
1990
LBP
Survey).
The
primary
objective
of
that
survey
was
to
estimate
the
prevalence
of
LBP
in
housing
­
not
to
address
the
presence
of
lead­
based
hazards
in
the
housing.
14
Since
1990,
there
have
been
advances
in
the
understanding
of
the
sources
and
pathways
of
lead
transport
and
exposure,
advances
in
the
protocols
for
collecting
samples
of
paint
and
dust
for
lead
contamination,
and
improvements
in
the
understanding
of
the
susceptibility
of
children
to
the
effects
of
lead
exposure
in
the
intervening
years.
For
example,
it
is
now
understood
that
lead­
contaminated
house
dust
from
LBP
is
most
often
the
primary
lead
hazard
for
children.
15,16,17
Also,
HUD
now
recommends,
and
HUD
and
EPA
require
in
their
regulations,
the
use
of
dust
wipe
sampling
as
opposed
to
the
vacuum
sampling
employed
in
the
1990
LBP
Survey.
In
addition,
the
1990
survey
data
are
dated
because
the
housing
stock
has
continued
to
evolve
as
older
houses
are
renovated,

repaired,
and/
or
demolished.
Thus,
it
may
not
serve
as
an
appropriate
estimate
for
evaluation
of
current
LBP
hazard
reduction
strategies.
Finally,
the
1990
LBP
Survey
excluded
certain
housing
categories
such
as
manufactured
housing,
and
housing
built
after
1979
(
i.
e.,
after
the
Consumer
Product
Safety
Commission's
ban
on
lead­
containing
residential
paint
went
into
effect).

The
NSLAH
has
updated
HUD's
1990
LBP
Survey
and
will
enable
an
assessment
of
progress
in
making
the
U.
S.
housing
stock
lead­
safe.
Further,
it
provides
current
baseline
information
needed
for
regulatory
and
policy
decisions
and
for
assessment
of
the
effectiveness
of
lead
hazard
reduction
strategies
currently
under
development.

14
In
Title
X
of
the
Housing
and
Community
Development
Act
of
1992
(
P.
L.
102­
550),
the
term
"
lead­
based
paint
hazard"
means
any
condition
that
causes
exposure
to
lead
from
lead­
contaminated
dust,
lead­
contaminated
soil,
lead­
contaminated
paint
that
is
deteriorated
or
present
in
accessible
surfaces,
friction
surfaces,
or
impact
surfaces
that
would
result
in
adverse
human
health
effects
as
established
by
the
appropriate
Federal
agency.

15
Clark,
S.,
Bornschein,
R.,
Succop,
P.,
et
al.
(
1985).
Conditions
and
type
of
housing
as
an
indicator
of
potential
environmental
lead
exposure
and
pediatric
blood
lead
levels.
Environ.
Res.
38,
pp.
46­
53.

16
Centers
for
Disease
Control
and
Prevention
(
1991).
Preventing
Lead
Poisoning
in
Young
Children.
Centers
for
Disease
Control
and
Prevention,
U.
S.
Department
of
Health
and
Human
Services,
Atlanta,
GA.

17
Lanphear,
B.
P.,
et
al.
(
1995).
The
Relation
of
Lead­
Contaminated
House
Dust
and
Blood
Lead
Levels
Among
Urban
Children,
Final
Report.
Report
to
the
U.
S.
Department
of
Housing
and
Urban
Development.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
1­
4
October
31,
2002
1.2
Survey
Objectives
HUD's
principal
lead­
related
purpose
for
the
NSLAH
was
to
develop
a
scientific
description
of
the
existing
lead
levels
in
dust,
soil,
and
paint
in
the
Nation's
housing.
In
addition,
the
survey
of
lead
hazards
in
homes
collected
data
to:

i.
Estimate
the
number
and
percent
of
homes
with
dust
and
soil
lead
levels
above
selected
thresholds.

ii.
Identify
likely
sources
of
lead
in
dust
in
housing,
e.
g.,
paint
and
soil.

iii.
Permit
future
analyses
of
lead
hazard
control
strategies
and
costs,
e.
g.,
quantities
of
deteriorated
painted
surfaces.

iv.
Permit
future
analyses
for
regulation,
policy,
and
guidance
that
minimize
regulatory
and
program
implementation
burden.

In
order
to
meet
the
survey
objectives,
a
nationally­
representative
sample
of
1,984
housing
units
(
HUs)
was
drawn
from
75
clusters
called
primary
sampling
units
(
PSUs).
18
A
general
three­
stage
sample
design
was
utilized
to
accomplish
these
goals
as
efficiently
as
possible.
A
total
of
831
eligible
HUs
were
recruited
into
the
survey.
In
each
recruited
HU,
samples
of
dust
and
soil
were
collected
and
painted
surfaces
were
tested.
(
See
Volume
II:
Design
and
Methodology
for
details
on
design
and
data
collection
protocols.)

1.2.1
Technical
Note
on
the
Survey
Weights
and
Estimation
Procedure
Paint
lead
measurements,
dust
samples,
and
general
area
soil
samples
were
collected
from
all
831
homes
in
the
sample.
In
contrast,
data
on
the
presence
of
children's
play
areas
and
play
area
soil
samples
were
collected
from
a
nationally
representative
statistical
subsample
of
375
homes
in
the
sample.

Consequently,
two
sets
of
survey
sampling
weights
have
been
developed:
one
for
the
full
sample
of
831
surveyed
homes;
and
one
for
the
subsample
of
375
homes
with
play
area
soil
lead
data.
The
construction
of
these
weights
is
described
in
Volume
II.
Both
sets
of
weights
are
unbiased;
they
will
both
produce
unbiased
national
estimates
to
characterize
the
target
population
of
all
95.7
million
occupied
housing
units
in
the
U.
S.

where
children
are
permitted
to
live.
However,
the
play
area
subsample,
being
smaller,
produces
wider
confidence
intervals
than
the
full
sample.
To
minimize
the
impact
of
this
fact
and
produce
the
most
efficient
18
A
PSU
is
a
metropolitan
statistical
area
(
MSA),
county,
or
cluster
of
counties
that
have
a
minimum
population
of
15,000
and
do
not
cross
Census
region
boundaries.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
1­
5
October
31,
2002
possible
estimates,
the
following
procedure
was
adopted.
Data
from
all
831
homes
were
used
to
estimate
paint,
dust,
and
non­
play­
area
soil
lead
hazards;
then
data
from
the
375
home
subsample
were
used
to
estimate
the
added
number
of
homes
with
only
play
area
soil
lead
hazards.
Further
details
on
this
estimation
procedure
are
provided
in
Appendix
D.

1.3
Report
Organization
The
report
for
the
NSLAH
consists
of
two
volumes:
Volume
I
presents
the
major
lead
hazard
findings.
Volume
II
presents
the
survey
design
and
methodology.

There
are
seven
chapters
in
Volume
I,
including
this
introduction.
Descriptions
of
each
chapter
are
as
follows:


Chapter
2
describes
the
population
surveyed
and
compares
the
survey
population
to
Current
Population
Survey
(
CPS)
and
American
Housing
Survey
(
AHS)
populations.


Chapter
3
presents
the
estimates
of
the
prevalence
of
significant
LBP
hazards
in
housing,
based
on
the
findings
presented
in
Chapters
4,
5,
and
6
for
paint,
dust,
and
soil,
respectively.
The
association
between
lead
in
each
of
the
matrices
(
paint,
dust,
soil)
is
presented,
as
well
as
the
prevalence
of
lead­
related
occupations
and
hobbies
among
housing
residents.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
1­
6
October
31,
2002

Chapter
4
presents
the
estimates
of
the
prevalence
and
amount
of
LBP
and
deteriorated
LBP
in
housing,
including
paint
lead
loadings
in
housing.
19
Relevant
estimates
are
compared
with
the
findings
of
the
1990
LBP
Survey.


Chapter
5
presents
the
estimates
of
the
prevalence
of
lead­
contaminated
dust
in
housing,
including
the
dust
lead
loadings
and
the
association
between
interior
dust
lead
and
LBP
condition.
Relevant
estimates
are
compared
with
the
findings
of
the
1990
LBP
Survey.


Chapter
6
presents
the
estimates
of
the
prevalence
of
residential
soil
lead,
including
soil
lead
concentrations
and
the
association
between
soil
lead
and
exterior
LBP
condition.
Relevant
estimates
are
compared
with
the
findings
of
the
1990
LBP
Survey.


Chapter
7
examines
the
quality
of
the
data
and
the
resulting
quality
of
projected
national
estimates.
The
chapter
addresses
nonresponse
rates
and
provides
a
summary
of
field
data
collection
quality
control
activities.
Classification
bias
due
to
measurement
error
is
discussed
in
Appendix
C.

19
Throughout
the
volume,
the
concepts
of
lead
loading
and
lead
concentration
are
used.
Lead
in
paint
and
dust
are
reported
as
loadings
(
mass
of
lead
per
unit
area
of
surface),
while
lead
in
soil
is
reported
as
a
concentration
(
mass
of
lead
per
unit
mass
of
soil).
For
paint,
lead
loading
is
the
number
of
milligrams
of
lead
per
square
centimeter
of
painted
surface
(
mg/
cm2).
For
dust,
lead
loading
is
the
number
of
micrograms
of
lead
per
square
foot
of
wiped
surface
(
µ
g/
ft2).
Soil
is
reported
as
the
number
of
micrograms
of
lead
per
gram
of
soil
(
µ
g/
g),
equivalent
to
parts
per
million
(
ppm).
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
2­
1
October
31,
2002

2.
SURVEYED
HOUSING
POPULATION
The
National
Survey
of
Lead
and
Allergens
in
Housing
(
NSLAH)
population
included
the
national
housing
stock
of
permanently­
occupied,
noninstitutional
housing
units
(
HUs),
including
multi­
family
buildings
and
manufactured
HUs,
i.
e.,
mobile
homes
and
trailers.
Homes
built
in
all
age
categories
in
all
50
states
and
the
District
of
Columbia
were
included.
Homes
built
before
1978
were
included
to
update
and
expand
upon
the
findings
of
the
1990
LBP
Survey.
Homes
built
in
1978
or
after
were
included
to
verify
the
assumption
that
newer
homes
have
minimal
lead
hazards,
based
on
the
1978
ban
of
lead­
based
paint
(
LBP)
for
residential
use.
Vacant
housing,
group
quarters,
hotels
and
motels,
military
bases,
and
short­
term
housing
were
excluded
because
of
difficulties
gaining
cooperation
and
are
consistent
with
exclusions
under
the
Lead
Safe
Housing
Rule.
Housing
where
children
were
not
permitted
to
live,
e.
g.,
elderly
care
facilities,
were
excluded
because
the
primary
interest
of
the
survey
was
in
children's
exposure
to
lead
and
allergens.

However,
a
home
was
not
excluded
simply
because
a
child
was
not
currently
residing
in
the
home
at
the
time
of
the
survey.
With
these
exclusions,
the
eligible
national
housing
stock
consisted
of
approximately
96
million
housing
units.

A
nationally­
representative
sample
of
1,984
HUs
was
drawn
from
75
clusters
called
primary
sampling
units
(
PSUs).
20
A
total
of
831
eligible
HUs
were
recruited
and
completed
the
survey.
Table
2.1
presents
the
national
estimates
for
selected
characteristics
of
the
survey
population,
including
geographic
region,
year
of
construction,
degree
of
urbanization,
presence
of
children
under
age
6
and
age
18,
tenure,

income,
poverty,
government
support,
race,
and
ethnicity.
21
All
estimates
presented
are
weighted
national
estimates
as
discussed
in
Volume
II.
Chapter
7
and
Appendix
C
of
this
volume
presents
an
extensive
discussion
of
the
potential
effect
of
nonresponse
bias.

One
important
measure
of
the
representativeness
of
the
NSLAH
is
to
examine
how
the
distributions
of
the
housing
characteristics,
socioeconomic
and
demographic
factors
compare
to
national
distributions.
National
distributions
were
obtained
from
the
1997
American
Housing
Survey
(
AHS)
and
the
1998
and
1999
Current
Population
Surveys
(
CPS).
The
weighted
percent
distribution
of
the
NSLAH
sample
20
A
PSU
is
a
metropolitan
statistical
area
(
MSA),
county,
or
cluster
of
counties
that
have
a
minimum
population
of
15,000
and
do
not
cross
Census
region
boundaries.

21
Cross
comparisons
of
two
variables,
e.
g.,
Region
by
Construction
Year
and
Poverty
by
Urbanization,
result
in
cells
containing
30
or
fewer
HUs.
Caution
is
recommended
in
the
interpretation
of
these
results.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
2­
2
October
31,
2002
by
race,
ethnicity,
income,
presence
of
a
child
under
18,22
Census
region,
year
of
construction,
single
family
vs.
multi­
family,
metropolitan
status,
and
tenure
(
owned
vs.
rented)
were
compared
with
that
of
the
available
AHS
and
CPS
data.
23
The
95
percent
confidence
intervals
for
the
NSLAH
sample
estimate
were
found
to
contain
the
AHS
or
CPS
estimate
for
most
of
the
available
statistics.
Slight
differences
in
estimates
were
observed
as
follows:


The
1997
AHS
estimate
of
35
percent
of
all
homes
being
in
the
South
is
slightly
lower
than
the
survey
estimate
of
36
percent
to
39
percent
of
all
homes
being
in
the
South.


The
1997
AHS
estimate
of
37
percent
of
all
homes
having
children
under
age
18
is
slightly
lower
than
the
survey
estimate
of
38
percent
to
39
percent
of
all
homes.


The
1998
CPS
estimate
of
26
percent
of
all
household
incomes
falling
in
the
$
0­
19,999
range
is
slightly
higher
than
the
survey
estimate
of
17
percent
to
24
percent
of
all
households
in
this
income
range.


The
1998
CPS
estimate
of
85
percent
of
all
households
not
in
poverty
is
slightly
higher
than
the
survey
estimate
of
77
percent
to
83
percent
of
all
households
not
in
poverty.

A
few
items
should
be
noted
which
affect
the
comparability
of
the
estimates
and
may
explain
the
above
observed
differences.
The
first
is
that
the
target
population
for
the
National
Survey
excludes
housing
that
excludes
children,
whereas
the
AHS
and
CPS
estimates
include
such
housing.
Second,
the
cut­
offs
used
for
defining
urbanization
were
not
exactly
the
same
for
the
NSLAH
and
the
CPS.
The
NSLAH
used
a
cut­
off
of
2,100,000
while
the
CPS
used
2,500,000.
Third,
for
the
income
and
poverty
comparisons,
the
CPS
uses
the
family
size
and
income
to
determine
poverty
status,
whereas
the
NSLAH
has
used
household
size
and
income.
24
The
NSLAH
estimates
of
any
particular
income
class
are
also
deflated
due
to
the
9
percent
of
respondents
whose
income
level
is
unknown.
Similarly,
there
are
6
percent
of
respondents
whose
poverty
status
is
unknown.
Fourth,
race
and
ethnicity
are
based
on
the
youngest
household
member
for
the
NSLAH,

22
While
we
were
most
interested
in
children
under
the
age
of
six
years
for
lead,
we
were
also
interested
in
all
children
up
to
age
18
for
allergen
exposures.
Comparative
data
from
the
AHS
are
only
available
for
children
under
age
18
in
the
household.
For
the
same
reason,
post­
stratification
for
this
survey
was
based
on
children
under
age
18.

23
If
AHS
or
CPS
data
are
not
listed
in
Table
2.1,
e.
g.,
for
Government
Support,
they
were
not
available
in
these
sources.

24
Family
size
includes
all
related
people
living
in
a
housing
unit.
Household
size
includes
all
people
living
the
housing
unit,
whether
or
not
they
are
related
to
each
other.
Thus
household
size
tends
to
be
larger
than
family
size.
The
1999
CPS
reports
an
average
household
size
of
3.17
and
an
average
family
size
of
2.62.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
2­
3
October
31,
2002
while
the
AHS
bases
these
data
on
the
first
householder
identified
over
the
age
of
18.
Fifth,
the
most
recent
AHS
available
is
for
1995
and
1997,
thus
the
AHS
data
are
slightly
out
of
date
as
compared
to
the
NSLAH.

Finally,
there
is
a
small
amount
of
sampling
error
in
both
the
AHS
and
CPS
estimates,
and
in
the
standard
error
estimates
for
all
three
surveys.
The
standard
error
for
both
AHS
estimates
(
percent
of
homes
in
the
south,
percent
of
homes
with
children
under
age
18)
is
approximately
0.25%.
25
The
difference
between
the
NSLAH
and
AHS
estimates
is
still
statistically
significant
for
both
variables.
CPS
standard
errors
are
of
a
comparable
magnitude
to
those
for
the
AHS
(
similar
sample
sizes
and
designs)
and
also
do
not
affect
the
statistical
significance
of
the
results.

25
American
Housing
Survey
1997,
Appendix
D,
http://
www.
census.
gov/
hhes/
www.
housing/
ahs/
meth.
html.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
2­
4
October
31,
2002
Table
2.1
Characteristics
of
the
National
Survey
Population,
with
Comparisons
to
the
American
Housing
Survey
(
AHS)
and
the
Current
Population
Survey
(
CPS)

HU
Characteristic
National
Survey
Estimates
HUs
in
sample
AHS
(
1997)
CPS
(
1998­
99)
c
Estimate
(
000)
Estimate
(%)
a
Lower
95%
CIb
(%)
Upper
95%
CI
(%)
Total
Housing
Unitsd
95,688
100%
831
Region:
Northeast
19,290
20%
19%
22%
155
20%
Midwest
22,083
23%
22%
24%
196
24%
South
35,474
37%
36%
39%
277
35%
West
18,841
20%
18%
21%
203
21%
Construction
year:
1978­
1998
29,774
31%
30%
32%
220
30%
1960­
1977
27,874
29%
28%
30%
267
30%
1940­
1959
20,564
21%
20%
23%
186
20%
Before
1940
17,476
18%
17%
20%
158
20%
Region
by
Construction
year:
Northeast
19,290
20%
19%
22%
155
20%
1978­
1998
4,358
5%
3%
6%
30
3%
1960­
1977
3,754
4%
3%
5%
30
5%
1940­
1959
4,261
5%
4%
5%
36
4%
Before
1940
6,917
7%
6%
8%
59
7%
Midwest
22,083
23%
22%
24%
196
24%
1978­
1998
4,801
5%
4%
6%
41
6%
1960­
1977
6,283
7%
6%
7%
55
7%
1940­
1959
5,899
6%
5%
7%
47
5%
Before
1940
5,101
5%
5%
6%
53
6%
South
35,474
37%
36%
39%
277
35%
1978­
1998
14,447
15%
14%
17%
95
14%
1960­
1977
11,261
12%
11%
12%
96
12%
1940­
1959
6,320
7%
6%
7%
57
6%
Before
1940
3,445
4%
3%
4%
29
4%
West
18,841
20%
17%
21%
203
21%
1978­
1998
6,169
6%
5%
8%
54
8%
1960­
1977
6,536
7%
6%
7%
85
7%
1940­
1959
4,124
4%
3%
6%
47
4%
Before
1940
2,013
2%
1%
3%
17
2%
Urbanization:
26
1999
MSA
equal
to
or
above
2
million
population
26,814
28%
24%
32%
276
30%

MSA
below
2
million
Population
45,753
48%
43%
53%
417
47%

Non­
MSA
23,121
24%
19%
30%
138
23%

26
The
cut­
off
used
with
survey
data
was
actually
metropolitan
statistical
areas
(
MSAs)
of
2,100,000
while
the
available
CPS
cut­
off
is
2,500,000.
This
difference
in
definitions
explains
the
slight
discrepancy
in
the
findings.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
2­
5
October
31,
2002
Table
2.1
Characteristics
of
the
Survey
Population,
with
Comparisons
to
the
American
Housing
Survey
(
AHS)
and
the
Current
Population
Survey
(
CPS)
(
continued)

HU
Characteristic
National
Survey
Estimates
HUs
in
sample
AHS
(
1997)
CPS
(
1998­
99)
3
Estimate
(
000)
Estimate
(%)
Lower
95%
CI
(%)
Upper95%
CI
(%)
One
or
more
children
under
age
6:
16,402
17%
15%
19%
184
17%

Refusal/
Don't
Knowe
352
5
One
or
more
children
under
age
18:
36,994
39%
38%
39%
398
37%

Refusal/
Don't
Know
290
3
Housing
Unit
Type:
Single
family
82,651
86%
84%
89%
705
88%
Multi­
family
13,037
14%
11%
16%
126
12%
Tenure:
1999
Owner­
occupied
66,232
69%
65%
73%
539
67%
Renter­
occupied
29,074
30%
27%
34%
289
33%
Refusal/
Don't
Know
381
3
Household
Income
($
30,000):
1998
Less
than
$
30,000/
year
33,830
35%
30%
41%
309
40%
Equal
to
or
more
than
$
30,000/
year
56,111
59%
54%
63%
482
60%

Refusal/
Don't
Know
5,747
40
Household
Income
($
20,000):
1998
$
0­
19,999/
year
19,359
20%
17%
24%
189
26%
$
20­
39,999/
year
25,855
27%
23%
31%
228
27%
$
40­
59,999/
year
19,316
20%
16%
25%
152
19%
Equal
to
or
more
than
$
60,000/
year
22,890
24%
20%
28%
203
28%

Refusal/
Don't
Know
8,268
59
Government
Support:
Government
support
4,809
5%
3%
7%
54
No
Government
support
86,070
90%
88%
92%
733
Refusal/
Don't
Know
4,809
5%
44
Poverty:
1998
In
poverty
13,221
14%
11%
16%
137
15%
Not
in
poverty
76,336
80%
77%
82%
651
85%
Refusal/
Don't
Know
6,130
6%
43
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
2­
6
October
31,
2002
Table
2.1
Characteristics
of
the
Survey
Population,
with
Comparisons
to
the
American
Housing
Survey
(
AHS)
and
the
Current
Population
Survey
(
CPS)
(
continued)

HU
Characteristic
National
Survey
Estimates
HUs
in
sample
AHS
(
1997)
CPS
(
1998­
99)
3
Estimate
(
000)
Estimate
(%)
Lower
95%
CI
(%)
Upper95%
CI
(%)
Poverty
by
Urbanization:
MSA
equal
to
or
above
2
million
population
26,814
28%
24%
32%
276
In
poverty
2,962
3%
2%
4%
35
Not
in
poverty
22,005
23%
19%
27%
226
Refusal/
Don't
Know
1,847
2%
15
MSA
below
2
million
population
45,753
48%
43%
53%
417
In
poverty
6,996
7%
5%
9%
75
Not
in
poverty
35,786
37%
34%
41%
323
Refusal/
Don't
Know
2,971
3%
19
Non­
MSA
23,121
24%
19%
30%
138
In
poverty
3,264
3%
2%
5%
27
Not
in
poverty
18,544
19%
14%
25%
102
Refusal/
Don't
Know
1,313
1%
9
Race:
White
77,005
80%
78%
83%
622
83%
African
American
10,365
11%
9%
13%
116
12%
Otherf
6,571
7%
5%
8%
77
6%
Refusal/
Don't
Know
1,746
2%
16
Ethnicity:
Hispanic/
Latino
7,434
8%
6%
10%
86
9%
Not
Hispanic/
Latino
87,008
91%
88%
93%
736
91%
Refusal/
Don't
Know
1,246
1%
9
a
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
Percentages
may
not
total
100%
due
to
rounding.
b
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
c
Current
Population
Survey
(
CPS)
data
was
taken
from
either
1998
or
1999
CPS,
as
indicated
by
the
boldface
year
at
the
top
of
each
section
of
the
column.
d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
e
Refusals
and
"
don't
know"
responses
by
survey
respondents.
f
"
Other"
race
includes
Asian,
American
Indian
or
Alaskan
Native,
Native
Hawaiian
or
other
Pacific
Islander,
and
more
than
one
race.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
1
October
31,
2002
3.
LEAD­
BASED
PAINT
(
LBP)
HAZARDS
IN
HOUSING
Chapter
3
presents
the
estimates
of
the
prevalence
of
lead­
based
paint
(
LBP)
hazards
in
housing,

based
on
the
findings
presented
in
Chapters
4,
5,
and
6.
The
associations
between
lead
in
each
of
the
matrices
(
paint,
dust,
soil)
are
presented.
In
addition,
the
prevalence
of
lead­
related
behaviors,
occupations,
and
hobbies
among
housing
residents
is
presented.
No
comparison
is
made
with
the
dust
lead
findings
of
the
1990
LBP
Survey
because
the
concept
of
hazard
from
the
earlier
survey
is
not
comparable
to
the
definitions
in
use
today.
The
effect
of
measurement
error
on
the
estimates
is
discussed
in
Appendix
C.

3.1
Definition
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
Under
Title
X,
a
LBP
hazard
is
defined
as
"
any
condition
that
causes
exposure
to
lead
from
leadcontaminated
dust;
bare,
lead
contaminated
soil;
LBP
that
is
deteriorated;
or
LBP
present
on
accessible
surfaces,
friction
surfaces,
or
impact
surfaces."
Because
the
data
collection
protocol
of
the
NSLAH
was
not
designed
as
a
conventional
risk
assessment
due
to
the
statistical
and
operational
considerations
discussed
below,
this
report
defines
significant
lead­
based
paint
(
LBP)
hazards
based
on
the
HUD
Lead
Safe
Housing
Rule
(
24
CFR
35.1320)
and
EPA
Lead
Hazards
Identification
Rule
(
40
CFR
745.65).
If
any
of
the
following
situations
exist
at
any
location
in
a
home,
a
significant
LBP
hazard
exists
in
the
home
under
this
definition:


Deteriorated
LBP
­
LBP
with
deterioration
larger
than
the
de
minimis
levels
per
Section
35.1350(
d)
of
the
Lead
Safe
Housing
rule
­
deterioration
of
more
than
20
square
feet
(
exterior)
or
2
square
feet
(
interior)
of
LBP
on
large
surface
area
components
(
walls,
doors),
or
damage
to
more
than
10%
of
the
total
surface
area
of
interior
small
surface
area
components
(
window
sills,
baseboards,
trim).
27
LBP
is
defined
as
any
paint
or
other
surface
coating
(
e.
g.,
varnish,
lacquer,
or
wallpaper
over
paint)
that
contains
lead
equal
to
or
greater
than
1.0
mg/
cm2);
or

Lead­
contaminated
dust
­
Dust
on
floors
with
greater
than
or
equal
to
40
µ
g/
ft2
lead,
dust
on
window
sills
with
greater
than
or
equal
to
250
µ
g/
ft2
lead28;
or

Lead­
contaminated
bare
soil
 
More
than
9
square
feet
of
bare
soil
with
a
lead
concentration
greater
than
or
equal
to
1,200
ppm,
or
400
ppm
for
bare
soil
in
an
area
frequented
by
a
child
under
the
age
of
6
years.

27
Intact
LBP
present
on
accessible
surfaces,
friction
surfaces,
or
impact
surfaces
were
not
included
in
the
definition
of
LBP
hazard
for
the
estimates
presented
in
this
report
because
this
information
was
not
specifically
collected
for
each
component.

28
Window
trough
dust
is
not
considered
in
the
definition
of
a
LBP
hazard
under
the
HUD
Lead
Safe
Housing
Rule.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
2
October
31,
2002
It
is
important
to
note
the
distinctions
between
the
significant
LBP
hazards
defined
here,

and
the
LBP
hazards
as
defined
in
the
EPA
Lead
Hazards
Identification
Rule,
which
does
not
specify
de
minimis
levels
for
deteriorated
LBP
and
non­
play
area
bare
soils.
In
addition,
the
significant
LBP
hazards
for
dust
and
soil
as
used
in
this
report,
although
applying
the
same
numerical
thresholds
of
the
EPA
Lead
Hazards
Identification
Rule,
are
based
on
the
maximum
dust
lead
and
soil
lead
measurements,
while
the
EPA
thresholds
are
based
on
the
average
dust
lead
and
soil
lead
measurements.

The
NSLAH
used
a
statistically­
based
sampling
strategy
in
order
to
obtain
statistically
valid
national
estimates.
The
NSLAH
took
fewer
measurements
in
a
home
than
a
full
risk
assessment
because
of
the
statistically­
based
strategy
of
maximizing
the
number
of
housing
units
tested
(
to
yield
the
most
representative
national
prevalence
estimates
with
the
resources
available),
and
HUD's
intention
to
minimize
the
burden
on
occupants
of
the
housing
units
being
tested.
The
subset
of
rooms
and
components
within
each
home
was
randomly
selected
and
evaluated
in
the
NSLAH
so
that
all
work
­
including
allergen
sampling
­
could
be
completed
in
a
2­
to­
3
hour
period
in
each
home.
For
the
same
reasons,
the
survey
did
not
assess
chewable
surfaces,
friction
surfaces,
or
impact
surfaces
as
required
for
conventional
risk
assessments.
In
summary,
the
statistical
nature,
operational
constraints,
and
objectives
of
the
NSLAH
required
defining
significant
LBP
hazards
in
the
manner
shown
above.

Under
this
definition,
a
home
is
described
as
having
significant
LBP
hazards
somewhere
in
the
home
if
any
significant
LBP
hazard
exists
at
any
location
in
the
home.
All
tables
and
figures
on
housing
units
with
significant
LBP
hazards
in
this
report
use
this
definition.

3.2
Prevalence
of
Significant
Lead­
Based
Paint
Hazards
in
Housing
An
estimated
24
million
(
±
3
million29)
or
25
percent
(
±
3%)
of
housing
units
in
the
United
States
have
significant
LBP
hazards.
Figure
3.1
presents
the
number
of
housing
units
with
significant
lead­
based
paint
hazards
by
selected
characteristics,
including
the
presence
of
a
resident
child
under
six
years
of
age,

housing
unit
age30,
measures
of
household
income,
race,
and
ethnicity.
Table
3.1
presents
the
number
and
29
All
confidence
intervals
are
at
the
95%
level
for
the
estimated
number
or
percent.

30
In
the
interpretation
of
the
data
by
housing
unit
age,
it
is
important
to
keep
the
source
of
the
data
in
mind.
Residents
were
asked
the
year
their
home
was
constructed.
If
a
resident
could
not
report
the
exact
year,
he/
she
was
asked
to
report
the
construction
year
in
ranges:
1978­
1998,
1960­
1977,
1946­
1959,
1940­
1945,
and
1939
or
before.
Over
40%
of
respondents
provided
the
construction
year
of
their
home
in
this
secondary
manner.
For
the
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
3
October
31,
2002
percentage
of
housing
units
with
significant
lead­
based
paint
hazards
by
a
much
wider
range
of
housing
unit
and
household
characteristics.

Homes
in
Northeastern
and
Midwestern
states
are
more
likely
to
have
significant
LBP
hazards
than
homes
in
Southern
or
Western
states.
An
estimated
40
percent
(
±
10%)
of
homes
in
the
Northeast
have
significant
LBP
hazards,
while
the
estimates
are
17
percent
(
±
4%)
and
15
(
±
6%)
percent
for
homes
in
the
South
and
West,
respectively.
Older
homes
are
more
likely
to
have
significant
LBP
hazards
than
newer
homes.
An
estimated
8
percent
(
±
4%)
of
homes
built
between
1960
and
1977
have
significant
LBP
hazards,

but
the
percentage
increases
to
43
percent
(
±
10%)
for
homes
built
between
1940
and
1959,
and
to
68
percent
(
±
11%)
for
homes
built
before
1940.
A
similar
pattern
of
results
was
found
for
homes
with
children
under
age
6
categorized
by
age
of
construction.

purposes
of
the
data
analyses
in
this
report,
the
midpoints
of
the
ranges
were
assigned
as
the
year
of
construction,
viz.,
1988,
1968,
1953,
1943,
and
1922,
respectively.
The
year
1922
is
not
the
midpoint
of
the
pre­
1940
range;
it
is
the
median
construction
year
for
pre­
1940
housing,
according
to
the
1995
AHS.
For
these
reasons,
housing
unit
age
is
reported
in
the
four
ranges
given
in
Table
3.1;
finer
breakdowns
should
be
interpreted
cautiously.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
4
October
31,
2002
Figure
3.1
Prevalence
of
Housing
Units
(
HUs)
with
Significant
LBP
Hazards
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
55,000
60,000
65,000
70,000
75,000
80,000
85,000
90,000
95,000
100,000
All
Occupied
HU's
With
Children
Under
Age
6
Built:
1978­
1998
1960­
1977
1940­
1959
Before
1940
In
Poverty
Income
<
$
30k/
year
Income
$
30k/
year
or
More
African
American
Hispanic/
Latino
Number
of
Housing
Units
(
000)

0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
Total
Housing
Units
(
000)

Upper
95%
CI
Lower
95%
CI
HU's
with
LBP
Hazards
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
5
October
31,
2002
Table
3.1
Prevalence
of
Housing
Units
with
Significant
Lead­
Based
Paint
(
LBP)
Hazards,
by
Selected
Characteristics
HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazardsa
Characteristic
All
HUs
(
000)
b
No.
of
HUs
with
Significant
LBP
Hazards
(
000)
Percent
of
HUs
with
Significant
LBP
Hazards
(%)
c
HUs
in
Sample
Estimate
Lower
95%
CId
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Total
Occupied
HUs
95,688
24,026
21,307
26,746
25%
22%
28%
831
Region:
Northeast
19,290
7,679
5,748
9,611
40%
30%
50%
155
Midwest
22,083
7,250
6,402
8,097
33%
29%
37%
196
South
35,474
6,191
4,964
7,419
17%
14%
21%
277
West
18,841
2,906
1,856
3,956
15%
10%
21%
203
Construction
Year:
1978­
1998
29,774
1,042
169
1,915
3%
1%
6%
220
1960­
1977
27,874
2,340
1,445
3,235
8%
5%
12%
267
1940­
1959
20,564
8,826
6,720
10,933
43%
33%
53%
186
Before
1940
17,476
11,818
10,045
13,591
68%
57%
78%
158
Region
by
Construction
Year:
Northeast
HUs
built
1978­
1998
4,358
76
0
225
2%
0%
5%
30
HUs
built
1960­
1977
3,794
1,478
348
2,609
39%
9%
69%
31
HUs
built
1940­
1959
4,221
3,089
2,179
3,999
73%
52%
95%
35
HUs
built
before
1940
6,917
5,957
5,187
6,728
86%
75%
97%
59
Midwest
HUs
built
1978­
1998
4,801
533
0
1,134
11%
0%
24%
41
HUs
built
1960­
1977
6,283
1,771
872
2,670
28%
14%
42%
55
HUs
built
1940­
1959
5,899
4,785
4,011
5,559
81%
68%
94%
47
HUs
built
before
1940
5,101
4,658
3,888
5,429
91%
76%
100%
53
South
HUs
built
1978­
1998
14,447
1,197
0
2,436
8%
0%
17%
95
HUs
built
1960­
1977
11,261
1,914
1,216
2,612
17%
11%
23%
96
HUs
built
1940­
1959
6,320
3,431
2,329
4,532
54%
37%
72%
57
HUs
built
before
1940
3,445
3,065
2,676
3,453
89%
78%
100%
29
West
HUs
built
1978­
1998
6,169
225
0
473
4%
0%
8%
54
HUs
built
1960­
1977
6,536
1,414
816
2,011
22%
12%
31%
85
HUs
built
1940­
1959
4,124
2,866
1,715
4,017
69%
42%
97%
47
HUs
built
before
1940
2,013
1,437
376
2,498
71%
19%
100%
17
Urbanization
MSA
>=
2
million
population
26,814
6,793
4,978
8,609
25%
19%
32%
276
MSA
=<
2
million
population
45,753
10,232
8,171
12,293
22%
18%
27%
417
Non­
MSA
23,121
7,001
3,848
10,153
30%
17%
44%
138
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
6
October
31,
2002
Table
3.1
Prevalence
of
Housing
Units
with
Significant
Lead­
Based
Paint
(
LBP)
Hazards,
by
Selected
Characteristics
(
continued)

HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazards1
Characteristic
All
HUs
(
000)
2
No.
of
HUs
with
Significant
LBP
Hazards
(
000)
Percent
of
HUs
with
Significant
LBP
Hazards
(%)
3
HUs
in
Sample
Estimate
Lower
95%
CI4
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
One
or
More
Children
Under
Age
6:
All
HU
ages
16,402
4,155
2,948
5,363
25%
18%
33%
184
HUs
built
1978­
1998
5,847
<
58g
­
­
<
1g
­
­
56
HUs
built
1960­
1977
5,098
469
0
940
9%
0%
18%
61
HUs
built
1940­
1959
3,055
1,732
1,088
2,375
57%
36%
78%
40
HUs
built
before
1940
2,401
1,955
1,190
2,720
81%
50%
113%
h
27
Housing
Unit
Type:
Single
family
82,651
21,584
18,974
24,194
26%
23%
29%
705
Multi­
family
13,037
2,442
1,208
3,676
19%
9%
28%
126
Tenure:
Owner­
occupied
66,232
15,305
13,191
17,419
23%
20%
26%
539
Renter­
occupied
29,074
8,721
6,583
10,859
30%
23%
37%
289
Refusal/
Don't
Knowe
381
3
Household
Income:
Less
than
$
30,000/
year
33,830
12,007
9,336
14,679
35%
28%
43%
309
Equal
to
or
more
than
$
30,000/
year
56,111
10,464
8,250
12,678
19%
15%
23%
482
Refusal/
Don't
Know
5,747
40
One
or
More
Children
Under
Age
6:
All
Income
Categories
16,402
4,155
2,948
5,363
25%
18%
33%
184
Less
than
$
30,000/
year
4,791
1,201
600
1,801
25%
13%
38%
61
Equal
to
or
more
than
$
30,000/
year
11,236
2,860
1,763
3,957
25%
16%
35%
117
Refusal/
Don't
Know
375
6
Government
Support:
Government
support
4,809
805
275
1,335
17%
6%
28%
54
No
government
support
86,070
22,198
19,252
25,144
26%
22%
29%
733
Refusal/
Don't
Know
4,809
44
Poverty:
In
Poverty
13,221
4,976
3,458
6,494
38%
26%
49%
137
Not
in
Poverty
76,336
16,576
13,598
19,555
22%
18%
26%
651
Refusal/
Don't
Know
6,130
43
Poverty
by
Urbanization:
MSA
equal
or
above
2
Million
population
In
poverty
2,962
1,205
735
1,674
41%
25%
57%
35
Not
in
poverty
22,005
7,758
5,957
9,559
35%
27%
43%
226
MSA
below
2
million
Population
In
poverty
6,996
3,795
2,248
5,341
54%
32%
76%
75
Not
in
poverty
35,786
12,455
9,722
15,188
35%
27%
42%
323
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
7
October
31,
2002
Table
3.1
Prevalence
of
Housing
Units
with
Significant
Lead­
Based
Paint
(
LBP)
Hazards,
by
Selected
Characteristics
(
continued)

HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazards1
Characteristic
All
HUs
(
000)
2
No.
of
HUs
with
Significant
LBP
Hazards
(
000)
Percent
of
HUs
with
Significant
LBP
Hazards
(%)
3
HUs
in
Sample
Estimate
Lower
95%
CI4
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Non­
MSA
In
poverty
3,264
1,362
310
2,414
42%
9%
74%
27
Not
in
poverty
18,544
8,684
5,071
12,297
47%
27%
66%
102
Refusal/
Don't
Know
if
in
Poverty
6,131
43
Race:
White
77,005
19,089
16,475
21,703
25%
21%
28%
622
African
American
10,365
2,969
1,807
4,131
29%
17%
40%
116
Otherf
6,571
1,496
672
2,321
23%
10%
35%
77
Refusal/
Don't
Know
1,746
16
Ethnicity:
Hispanic/
Latino
7,434
2,399
1,235
3,564
32%
17%
48%
86
Not
Hispanic/
Latino
87,008
21,196
18,674
23,719
24%
21%
27%
736
Refusal/
Don't
Know
1,246
9
a
Significant
LBP
hazard
as
defined
in
text
and
HUD
Lead
Safe
Housing
Rule.
b
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
c
All
percentages
are
calculated
with
the
"
All
HUs"
column
in
each
row
used
as
the
denominator.
d
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
e
Refusals
and
"
don't
know"
responses
by
survey
respondents.
f
"
Other"
race
includes
Asian,
American
Indian
or
Alaskan
Native,
Native
Hawaiian
or
other
Pacific
Islander,
and
more
than
one
race.
g
No
1978­
1988
housing
units
with
one
or
more
children
<
6
years
old
in
this
sample
have
lead­
based
paint
hazards.
h
Upper
95%
CI
value
>
100%
reflects
uncertainty
in
number
of
housing
units
in
first
data
column.

More
homes
with
lower
income
occupants
have
significant
LBP
hazards
than
homes
where
occupants
have
higher
incomes.
An
estimated
35
percent
(
±
8%)
of
households
with
less
than
$
30,000/
year
income
have
significant
LBP
hazards,
compared
with
19
percent
(
±
4%)
of
households
in
the
$
30,000/
year
or
above
income
level.

Government­
supplied
housing
may
have
fewer
lead­
based
paint
hazards
than
housing
without
Government
support.
An
estimated
17
percent
of
Government­
supported
housing
had
significant
lead­
based
paint
hazards,
compared
to
26
percent
of
housing
without
Government
support.

Table
3.2
presents
the
number
of
homes
with
significant
LBP
hazards
by
location
in
the
building 
either
interior
or
exterior,
or
both.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
8
October
31,
2002
Table
3.2
Prevalence
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
by
Location
in
the
Building
HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazards
LBP
Hazard
Location
Number
of
HUsa
(
000)
Percent
of
HUsb
HUs
in
Sample
Estimate
Lower
95%
CIc
Upper
95%
CI
Percent
Lower
95%
CI
Upper
95%
CI
Interior
only
8,823
6,439
11,207
9%
7%
12%
63
Both
Interior
and
Exterior
8,869
6,634
11,104
9%
7%
12%
99
Exterior
only
6,334
4,741
7,928
7%
5%
8%
48
Anywhere
24,026
21,307
26,746
25%
22%
28%
210
No
Significant
LBP
Hazard
71,661
68,498
74,825
75%
72%
78%
621
Total
HUs
95,688
100%
831
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
Percentages
may
not
total
100%
due
to
rounding.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

Table
3.3
presents
data
for
the
presence
of
significant
LBP
hazards
in
homes
by
type
of
hazard,

for
all
homes
in
the
National
Survey's
target
population
and
for
homes
with
one
or
more
children
under
the
age
of
6
years.
The
percentages
for
each
"
All
HUs"
row
of
Table
3.3
show
the
percent
of
all
HUs
with
the
component
of
significant
LBP
hazard,
while
the
percentages
in
each
"
HUs
w/
Child
Under
6"
row
of
Table
3.3
show
the
percent
of
all
HUs
with
a
child
under
age
6
with
that
component
of
significant
LBP
hazard.

Table
3.4
breaks
out
the
data
in
Table
3.3
for
all
HU's
by
construction
year.
All
three
components
of
significant
lead­
based
paint
hazards
show
the
same
pattern
of
substantially
greater
prevalence
of
hazards
among
older
housing
units,
especially
pre­
1940
homes.
For
all
housing
unit
ages,
soil
lead
hazards
have
the
lowest
prevalence.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
9
October
31,
2002
Table
3.3
Prevalence
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
in
Housing
Units
with
a
Child
Under
6
Years
of
Age
by
Type
of
Hazard
HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazards
Type
of
Hazard
Number
of
HUsa
(
000)
Percent
of
HUsb
(%)

Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Significantly
Deteriorated
Lead
Based
Paint
All
HUs
13,634
10,928
16,341
14%
11%
17%
HUs
w/
Child
Under
6
2,519
1,715
3,324
15%
10%
20%
Interior
Lead
Dust
All
HUs
15,468
12,982
17,954
16%
14%
19%
HUs
w/
Child
Under
6
2,634
1,587
3,681
16%
10%
22%
Lead
Contaminated
Soil
All
HUs
6,460
3,122
9,799
7%
3%
10%
HUs
w/
Child
Under
6
1,511
0
3,108
9%
0%
19%
Any
LBP
Hazard
All
HUs
24,026
21,306
26,746
25%
22%
28%
HUs
w/
Child
Under
6
4,155
2,948
5,363
25%
18%
33%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
Percentages
are
calculated
with
total
housing
units
(
95,688)
or
with
housing
units
with
a
child
under
age
6
(
16,402)
as
the
denominator,
as
applicable.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
10
October
31,
2002
Table
3.4
Prevalence
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
in
Housing
Units
by
Type
of
Hazard
and
Housing
Unit
Age
HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazards
Type
of
Hazard
Number
of
HUsa
(
000)
Percent
of
HUsb
(%)

Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Significantly
Deteriorated
Lead
Based
Paint
Built
1978­
1998
83
0
240
0%
0%
1%
Built
1960­
1977
610
91
1,128
2%
0%
4%
Built
1940­
1959
5,190
3,367
7,013
25%
16%
34%
Built
Before
1940
7,752
6,029
9,475
44%
34%
54%

Interior
Lead
Dust
Built
1978­
1998
959
98
1,821
3%
0%
6%
Built
1960­
1977
1,943
1,173
2,714
7%
4%
10%
Built
1940­
1959
4,665
3,181
6,150
23%
15%
30%
Built
Before
1940
7,735
5,982
9,489
44%
34%
54%

Lead
Contaminated
Soil
Built
1978­
1998
0
0
0
0%
0%
0%
Built
1960­
1977
130
0
263
0%
0%
1%
Built
1940­
1959
2,562
0
3,830
12%
0%
19%
Built
Before
1940
3,867
254
4,741
22%
1%
27%

Any
LBP
Hazard
Built
1978­
1998
1,042
169
1,914
3%
1%
6%
Built
1960­
1977
2,340
1,445
3,235
8%
5%
12%
Built
1940­
1959
8,826
6,364
10,932
43%
31%
53%
Built
Before
1940
11,818
9,688
13,591
68%
55%
78%
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
Percentages
are
calculated
with
housing
units
built
in
that
time
period
as
the
denominator.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
11
October
31,
2002
3.3
Prevalence
of
Lead­
Related
Occupations
or
Hobbies
Table
3.5
presents
the
number
and
percent
of
all
U.
S.
households
in
which
at
least
one
occupant
engages
in
a
lead­
related
occupation
or
hobby.
Data
for
home
cleanliness
and
clutter
categories
are
also
presented.
Table
3.6
presents
the
same
data
for
homes
with
significant
LBP
hazards.
As
described
below,
all
of
these
estimates
are
likely
to
overstate
the
number
of
households
that
may
have
contributions
to
lead
in
dust
from
these
behaviors.

An
estimated
24
percent
(
±
3%)
of
households
report
that
at
least
one
occupant
engages
in
a
listed
lead­
related
occupation,
e.
g.,
construction
or
renovation
work,
lead
industry
work,
automotive
repair
or
radiator
work,
or
firing
range
work31.
This
may
be
elevated
above
the
actual
estimate
of
people
who
may
bring
lead
home
due
to
the
fact
that
many
people
in
the
construction
business
only
work
with
new
construction
or
in
projects
which
that
do
not
involve
disturbing
LBP,
dust­
lead
hazards
or
soi6l­
lead
hazards.
Similarly,
a
person
working
in
a
lead­
related
industry
may
have
an
administrative
position
and
have
no
lead
exposure
at
all.

An
estimated
41
percent
(
±
5%)
report
that
at
least
one
occupant
engages
in
a
potentially
leadrelated
hobby
at
home,
e.
g.,
making
bullets
or
sinkers,
furniture
or
home
renovation,
stained
glass,
pottery,
or
making
jewelry.
32
Among
homes
with
significant
LBP
hazards,
31
percent
(
±
8%)
report
that
at
least
one
occupant
engages
in
a
potentially
lead­
related
hobby.
These
may
be
high
estimates
of
the
number
of
homes
where
lead
dust
is
actually
generated
since
some
of
these
people
may
generally
or
always
use
lead­
free
materials
in
their
hobbies.

Home
cleanliness
has
been
associated
with
lead
dust
levels.
33
About
half
of
all
homes
were
found
to
be
clean
(
59%)
and
organized
(
43%),
using
the
criteria
in
this
survey.
Homes
with
significant
LBP
hazards
in
their
interiors
were
generally
somewhat
less
clean
and
organized;
the
percentage
of
clean
homes
is
36%,

31
A
respondent
was
considered
to
be
engaged
in
a
lead­
related
occupation
if
they
worked
on
any
of
the
following
activities
in
the
previous
six
months:
building
demolition,
paint
removal
(
including
sanding
or
scraping),
plumbing,
sandblasting,
battery
manufacturing
or
salvage
work,
explosive
or
ammunition
work,
foundry
work,
glass
work,
lead
smelter
work,
oil
refinery
work,
car
radiator
repair,
making
or
splicing
cable,
work
at
a
firing
range
or
police
work,
welding
or
torch
cutting,
or
other
lead­
related
industry
work.

32
A
respondent
was
counted
as
engaged
in
a
potentially
lead­
related
activity
at
home
if
they
had
participated
in
any
of
the
following
activities
in
the
previous
six
months:
make
bullets
or
fishing
sinkers,
paint
cars
or
bicycles,
reload
bullets,
target
shoot,
hunt,
remove
paint
from
any
part
of
the
house,
remove
paint
from
furniture,
sand
or
paint
any
part
of
the
house,
solder
pipes
or
metal,
solder
electronic
parts,
use
artists'
paint
(
jewelry,
pictures),
work
with
stained
glass,
or
work
with
pottery
or
glazes.
However,
painting
and
renovation
work
on
homes
built
after
1978
were
excluded
from
these
estimates.

33
NCLSH
(
1998).
Evaluation
of
the
HUD
Lead­
Based
Paint
Hazard
Control
Grant
Program,
Fifth
Interim
Report,
March
1998,
Prepared
for
the
U.
S.
Department
of
Housing
and
Urban
Development
by
the
National
Center
for
Lead­
Safe
Housing.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
3­
12
October
31,
2002
23%
lower
than
the
general
population,
and
the
percentage
of
organized
homes
is
28%,
15%
lower
than
the
general
population.

Table
3.5
Prevalence
of
Housing
Units
with
Selected
Lead­
Related
Characteristics
Lead
Related
Behavior
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
HUs
in
Sample
Estimatec
Lower
95%
CId
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Lead
Related
Occupation
22,673
19,732
25,615
24%
21%
27%
203
Lead
Related
Hobby
39,281
35,020
43,543
41%
36%
46%
347
Cleanliness
House
Appears
Clean
56,058
51,887
60,228
59%
54%
63%
462
Some
Evidence
of
Cleaning
25,347
21,417
29,277
26%
22%
31%
237
No
Evidence
of
Cleaning
9,646
7,577
11,714
10%
8%
12%
86
Clutter
Clutter
Organized
41,158
37,650
44,666
43%
40%
46%
347
Average
Amount
of
Clutter
38,601
35,663
41,539
40%
37%
43%
336
No
Organization
11,045
8,859
13,231
12%
9%
14%
100
Total
HUs
95,688
831
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
Percentages
may
not
total
100%
due
to
rounding.
c
Estimates
are
based
on
the
full
weighted
sample.
d
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

Table
3.6
Prevalence
of
Selected
Lead­
Related
Characteristics
in
Homes
with
Significant
Interior
LBP
Hazards
Lead
Related
Behavior
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
HUs
in
Sample
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Lead
Related
Occupation
4,990
3,195
6,785
28%
18%
38%
45
Lead
Related
Hobby
5,485
4,043
6,926
31%
23%
39%
57
Cleanliness
House
Appears
Clean
6,360
4,030
8,691
36%
23%
49%
60
Some
Evidence
of
Cleaning
6,757
5,221
8,294
38%
30%
47%
63
No
Evidence
of
Cleaning
3,258
1,646
4,870
18%
9%
28%
28
Clutter
Clutter
Organized
5,041
3,052
7,029
28%
17%
40%
44
Average
Amount
of
Clutter
7,899
6,386
9,412
45%
36%
53%
77
No
Organization
3,436
1,911
4,961
19%
11%
28%
30
Total
HUs
17,692
162
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
with
significant
interior
LBP
hazard
(
18,827)
as
the
denominator.
Percentages
may
not
total
100%
due
to
rounding.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
1
October
31,
2002
4.
LEAD­
BASED
PAINT
(
LBP)
IN
HOUSING
Chapter
4
presents
estimates
of
the
prevalence,
location,
and
amount
of
lead­
based
paint
(
LBP)

and
deteriorated
LBP
in
housing,
including
paint
lead
loadings
in
housing.
Relevant
estimates
are
compared
with
the
findings
of
the
1990
LBP
Survey.

Under
the
HUD
Lead
Safe
Housing
Rule
(
24
CFR
35
Subparts
B­
R),
LBP
is
defined
as
any
paint
or
other
surface
coating
(
e.
g.,
varnish,
lacquer,
or
wall­
paper
over
paint)
that
contains
lead
equal
to
or
greater
than
1.0
mg/
cm2.
The
estimates
for
deteriorated
LBP
and
significantly
deteriorated
LBP
are
presented
in
Section
4.2.
Under
the
Lead
Safe
Housing
Rule,
LBP
is
considered
to
be
deteriorated
if
there
is
any
deterioration.
It
is
considered
to
be
significantly
deteriorated
if
the
deterioration
exceeds
the
de
minimis
thresholds
given
in
the
definition
of
a
significant
LBP
hazard
presented
in
Chapter
3.

4.1
Prevalence
of
Lead­
Based
Paint
An
estimated
38
million
(
±
3
million34)
or
40
percent
(
±
4%)
of
housing
units
(
HUs)
in
the
United
States
have
LBP
on
either
the
interior
or
exterior
painted
surfaces,
or
both.
Figures
4.1
and
4.2
present
the
percentage
of
housing
units
with
LBP
by
selected
characteristics,
including
presence
of
children
under
age
6,

geographic
region,
housing
unit
type,
tenure,
race,
and
year
of
construction35.
Table
4.1
presents
the
number
and
percentage
of
housing
units
with
LBP
by
a
much
wider
range
of
housing
unit
and
household
characteristics.

The
data
suggest
that
homes
in
northeastern
and
midwestern
states
are
more
likely
to
have
LBP
than
homes
in
southern
or
western
states.
An
estimated
55
percent
and
53
percent
of
homes
in
the
Northeast
and
Midwest
have
LBP,
while
the
estimates
are
27
percent
and
32
percent
for
homes
in
the
South
and
West,

respectively.
This
finding
can
be
explained
by
the
fact
that
the
housing
stock
in
the
Northeast
and
Midwest
is
older.

34
All
confidence
intervals
are
at
the
95%
level
for
the
estimated
number
or
percent.

35
In
the
interpretation
of
the
data
by
housing
unit
age,
it
is
important
to
keep
the
source
of
the
data
in
mind.
Residents
were
asked
the
year
their
home
was
constructed.
If
a
resident
could
not
report
the
exact
year,
he/
she
was
asked
to
report
the
construction
year
in
ranges:
1978­
1998,
1960­
1977,
1946­
1959,
1940­
1945,
and
1939
or
before.
Over
40%
of
respondents
provided
the
construction
year
of
their
home
in
this
secondary
manner.
For
the
purposes
of
the
data
analyses
in
this
report,
the
midpoints
of
the
ranges
were
assigned
as
the
year
of
construction,
viz.,
1988,
1968,
1953,
1943,
and
1922,
respectively.
The
year
1922
is
not
the
midpoint
of
the
pre­
1940
range;
it
is
the
median
construction
year
for
pre­
1940
housing,
according
to
the
1995
AHS.
For
these
reasons,
housing
unit
age
is
reported
in
most
tables
in
the
four
ranges
given
in
Table
3.1;
finer
breakdowns
should
be
interpreted
cautiously.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
2
October
31,
2002
0%
10%
20%
30%
40%
50%
60%

All
HU's
HU's/
Kids<
6
HU's/
Kids<
6/<$
3
0k
Northea
st
Midwest
West
South
Single
Family
Multi­
family
Renter­
Occupied
Own
er­
Occu
pied
White
Oth
ers
Percent
of
HU's
Figure
4.1
Prevalence
of
LBP
by
Selected
Housing
Unit
Characteristics
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
3
October
31,
2002
Figure
4.2
Prevalence
of
HUs
with
LBP
by
Construction
Year
&
Presence
of
Children
<
6
As
expected,
older
homes
are
more
likely
to
have
LBP
than
newer
homes.
An
estimated
24
percent
(+
6%)
of
homes
built
between
1960
and
1977
have
LBP,
but
the
percentage
increases
to
69
percent
(+
9%)
for
homes
built
between
1940
and
1959,
and
to
87
percent
(+
5%)
for
homes
built
before
1940.
Table
4.1
indicates
that
5
to
8
percent
of
homes
built
after
1977
have
LBP.
This
estimate
is
likely
to
be
somewhat
high,
for
two
reasons.
First,
housing
unit
age
is
based
on
the
residents'
reports.
Some
residents,
especially
renters,
may
have
reported
their
homes
as
being
newer
than
they
actually
are.
There
were
a
few
homes
in
the
survey
in
which
an
examination
of
all
of
the
data
collected
from
a
home
presented
a
picture
that
suggested
that
the
home
may
be
older
than
reported
by
the
respondent.
Even
so,
in
no
case
was
the
respondent's
reported
age
overridden
in
the
analyses.
Second,
most
of
the
homes
in
the
sample
built
after
1977
that
had
LBP
had
only
one
or
two
components
measured
with
LBP.
In
approximately
one­
third
of
these
homes,
the
substrate
of
the
one
painted
component
in
the
home
may
have
interfered
with
the
reading
(
these
included
painted
metal,

ceramic,
or
stone
substrates
which
may
contain
lead,
but
paint
was
not
scraped
to
measure
bare
substrate
for
this
purpose).
36
36
The
XRF
analyzer
used
for
the
study
corrected
for
substrate
interferences,
but
any
actual
lead
in
the
substrate
would
be
measured.
0
10
20
30
40
50
60
70
80
90
100
All
HUs
Children<
6
HUs
(%)
<
1940
1940­
59
1960­
77
1978­
98
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
4
October
31,
2002
Table
4.1
Prevalence
of
Lead­
Based
Paint
(
LBP)
by
Selected
Housing
Unit
(
HU)
Characteristics
HU
Characteristic
Number
of
HUs
with
LBP
(
000)
Percent
of
HUs
with
LBP
(%)
a
HUs
in
Sample
All
HUs
(
000)
Estimate
Lower
95%
CIb
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Total
Housing
Unitsc
95,688
37,897
34,521
41,272
40%
36%
43%
831
Region:
Northeast
19,290
10,600
8,306
12,895
55%
46%
64%
155
Midwest
22,083
11,748
10,546
12,950
53%
48%
59%
196
South
35,474
9,607
7,762
11,451
27%
22%
32%
277
West
18,841
5,942
4,747
7,137
32%
25%
38%
203
Construction
Year:
1989­
1998
10,378
514
­
1,444
5%
0%
14%
61
1978­
1988
19,397
1,517
549
2,485
8%
3%
13%
159
1960­
1977
27,874
6,577
4,875
8,280
24%
18%
30%
267
1940­
1959
20,564
14,171
12,203
16,139
69%
60%
77%
186
Before
1940
17,476
15,117
13,532
16,702
87%
82%
91%
158
Region
by
Construction
Year:
Northeast
HUs
built
1978­
1998
4,358
76
0
225
2%
0%
5%
30
HUs
built
1960­
1977
3,794
1,478
348
2,609
39%
9%
69%
31
HUs
built
1940­
1959
4,221
3,089
2,179
3,999
73%
52%
95%
35
HUs
built
before
1940
6,917
5,957
5,187
6,728
86%
75%
97%
59
Midwest
HUs
built
1978­
1998
4,801
533
0
1,134
11%
0%
24%
41
HUs
built
1960­
1977
6,283
1,771
872
2,670
28%
14%
42%
55
HUs
built
1940­
1959
5,899
4,785
4,011
5,559
81%
68%
94%
47
HUs
built
before
1940
5,101
4,658
3,888
5,429
91%
76%
100%
53
South
HUs
built
1978­
1998
14,447
1,197
0
2,436
8%
0%
17%
95
HUs
built
1960­
1977
11,261
1,914
1,216
2,612
17%
11%
23%
96
HUs
built
1940­
1959
6,320
3,431
2,329
4,532
54%
37%
72%
57
HUs
built
before
1940
3,445
3,065
2,676
3,453
89%
78%
100%
29
West
HUs
built
1978­
1998
6,169
225
0
473
4%
0%
8%
54
HUs
built
1960­
1977
6,536
1,414
816
2,011
22%
12%
31%
85
HUs
built
1940­
1959
4,124
2,866
1,715
4,017
69%
42%
97%
47
HUs
built
before
1940
2,013
1,437
376
2,498
71%
19%
100%
17
Urbanization:
MSA
equal
or
above
2
million
population
26,814
9,681
7,550
11,812
36%
30%
42%
276
MSA
below
2
million
Population
45,753
17,390
14,026
20,754
38%
32%
44%
417
Non­
MSA
23,121
10,826
7,458
14,193
47%
35%
59%
138
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
5
October
31,
2002
Table
4.1
Prevalence
of
Lead­
Based
Paint
(
LBP)
by
Selected
Housing
Unit
(
HU)
Characteristics
(
continued)

HU
Characteristic
Number
of
HUs
with
LBP
(
000)
Percent
of
HUs
with
LBP
(%)
a
HUs
in
Sample
All
HUs
(
000)
Estimate
Lower
95%
CIb
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
One
or
More
Children
Under
Age
6:
All
HU
Ages
16,402
5,328
4,048
6,609
32%
26%
39%
184
HUs
built
1978­
1998
5,847
202
0
436
3%
0%
7%
56
HUs
built
1960­
1977
5,098
876
416
1,337
17%
8%
26%
61
HUs
built
1940­
1959
3,055
1,997
1,341
2,654
65%
44%
87%
40
HUs
built
before
1940
2,401
2,253
1,426
3,079
94%
59%
100%
27
Housing
Unit
Type:
Single
family
82,651
34,081
30,874
37,289
41%
37%
45%
705
Multi­
family
13,037
3,815
2,470
5,160
29%
20%
39%
126
Tenure:
Owner­
occupied
66,232
25,172
22,400
27,943
38%
35%
41%
539
Renter­
occupied
29,074
12,409
9,538
15,281
43%
35%
50%
289
Refusal/
Don't
Knowd
381
3
Household
Income:
Less
than
$
30,000/
year
33,830
15,007
11,604
18,411
44%
37%
52%
309
Equal
to
or
more
than
$
30,000/
year
56,111
20,815
17,745
23,885
37%
32%
42%
482
Refusal/
Don't
Know
5,747
40
One
or
More
Children
Under
Age
6:
All
Income
Categories
16,402
5,328
4,048
6,609
32%
26%
39%
184
Less
than
$
30,000/
year
4,791
1,375
784
1,965
29%
16%
41%
61
Equal
to
or
more
than
$
30,000/
year
11,236
3,820
2,579
5,061
34%
23%
45%
117
Refusal/
Don't
Know
375
6
Government
Support:
Government
support
4,809
1,741
678
2,805
36%
16%
56%
54
No
government
support
86,070
33,871
30,681
37,062
39%
36%
43%
733
Refusal/
Don't
Know
4,809
44
Poverty
by
Urbanization:
MSA
equal
or
above
2
Million
population
In
poverty
2,962
1,205
735
1,674
41%
25%
57%
35
Not
in
poverty
22,005
7,758
5,957
9,559
35%
27%
43%
226
MSA
below
2
million
Population
In
poverty
6,996
3,795
2,248
5,341
54%
32%
76%
75
Not
in
poverty
35,786
12,455
9,722
15,188
35%
27%
42%
323
Non­
MSA
In
poverty
3,264
1,362
310
2,414
42%
9%
74%
27
Not
in
poverty
18,544
8,684
5,071
12,297
47%
27%
66%
102
Refusal/
Don't
Know
if
in
Poverty
6,131
43
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
6
October
31,
2002
Table
4.1
Prevalence
of
Lead­
Based
Paint
(
LBP)
by
Selected
Housing
Unit
(
HU)
Characteristics
(
continued)

HU
Characteristic
Number
of
HUs
with
LBP
(
000)
Percent
of
HUs
with
LBP
(%)
a
HUs
in
Sample
All
HUs
(
000)
Estimate
Lower
95%
CIb
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Race:
White
77,005
30945
28,037
33853
40%
37%
44%
622
African
American
10,365
4,228
2,767
5,689
41%
30%
52%
116
Othere
6,571
1,913
1,015
2,811
29%
17%
41%
77
Unknown
1,746
16
Ethnicity:
Hispanic/
Latino
7,434
3,329
2,044
4,614
45%
31%
59%
86
Not
Hispanic/
Latino
87,008
33,830
30,436
37,223
39%
35%
42%
736
Refusal/
Don't
Know
1,246
9
a
All
percentages
are
calculated
with
the
"
all
HUs"
on
the
left
most
column
of
each
row
as
the
denominator.
b
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
c
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
d
Refusals
and
"
don't
know"
responses
by
survey
respondents.
e
"
Other"
race
includes
Asian,
American
Indian
or
Alaskan
Native,
Native
Hawaiian
or
other
Pacific
Islander,
and
more
than
one
race.

An
estimated
5.3
million
(
±
1.3
million)
or
32
percent
(
±
6%)
of
homes
with
children
under
the
age
of
6
years
have
lead­
based
paint,
although
children
are
eligible
to
live
in
all
of
the
estimated
38
million
homes
with
lead­
based
paint.
Homes
with
children
under
age
6
showed
the
same
relationship
between
HU
age
and
the
presence
of
LBP
as
do
all
homes.

The
differences
among
LBP
prevalence
by
urbanization,
single
family
versus
multi­
family
housing,
occupant
status,
household
income,
race,
ethnicity,
and
poverty
crossed
with
urbanization
do
not
appear
to
be
significant
in
that
the
confidence
intervals
overlap.
Likewise,
there
were
no
differences
in
LBP
prevalence
when
one
or
more
children
under
age
6
was
crossed
by
construction
year.

Figure
4.3
and
Table
4.2
present
the
number
of
homes
with
LBP
by
location
in
the
building
 

either
interior
or
exterior,
or
both.
About
one­
half
of
homes
with
lead­
based
paint
have
it
on
both
interior
and
exterior
surfaces
(
21%
of
all
homes,
or
53%
of
homes
with
LBP
anywhere
in
the
building).
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
7
October
31,
2002
Table
4.2
Prevalence
of
Lead­
Based
Paint
(
LBP)
by
Location
in
the
Building
LBP
Location
Number
of
HUsa
with
LBP
(
000)
Percent
of
HUs
with
LBP
(%)
b
HUs
in
Sample
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Interior
Only
8,609
6,102
11,116
9%
6%
12%
77
Both
Interior
and
Exterior
20,260
17,961
22,558
21%
19%
24%
181
Exterior
Only
9,028
6,535
11,521
9%
7%
12%
80
Subtotal
 
LBP
anywhere
in
Building
37,897
34,521
41,272
40%
36%
43%
338
No
LBP
in
Building
57,791
54,624
60,959
60%
57%
64%
493
Total
HUs
95,688
100%
831
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
Percentages
may
not
total
100%
due
to
rounding.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

Figure
4.3
Prevalence
of
Lead
Based
Paint
(
LBP)
by
Location
in
the
Building
Numbers
of
Estimated
Number
of
Housing
Units
No
LBP
in
Building
57,791
Exterior
LBP
Only
9,028
Interior
LBP
Only
8,609
Both
Interior
and
Exterior
LBP
20,260
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
8
October
31,
2002
4.2
Prevalence
of
Deteriorated
Lead­
Based
Paint
Although
there
are
many
homes
with
LBP,
the
condition
of
the
paint
is
important
in
determining
whether
a
hazard
exists.
Except
during
renovations,
maintenance,
or
other
activities
that
could
disturb
it,

intact
lead­
based
paint
is
believed
to
pose
little
immediate
risk
to
occupants.
However,
significantly
deteriorated
lead­
based
paint
may
present
an
immediate
danger
to
occupants,
especially
to
young
children.

Table
4.3
presents
the
number
and
percentage
of
HUs
with
deteriorated
LBP
and
significantly
deteriorated
LBP
by
location
in
the
building
­
either
interior
or
exterior,
or
both.

Table
4.3
Prevalence
of
Deteriorated
and
Significantly
Deteriorated
Lead­
Based
Paint
(
LBP)
by
Location
in
the
Building
Deteriorated
LBP
Location
Number
of
HUsa
with
Deteriorated
LBP
(
000)
Percentb
of
HUs
with
Deteriorated
LBP(%)
HUs
in
Sample
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Interior
Only
4,180
2,851
5,509
4%
3%
6%
39
Both
Interior
and
Exterior
6,236
4,661
7,811
7%
5%
8%
62
Exterior
Only
7,009
4,922
9,097
7%
5%
10%
61
Total
with
Deteriorated
LBP
17,425
14,816
19,735
18%
15%
21%
162
No
Deteriorated
LBP
78,263
75,953
80,572
82%
79%
84%
669
TOTAL
95,688
100%
831
Significantly
Deteriorated
LBP
Location
Number
of
HUsa
with
Significant
Deteriorated
LBP
(
000)
Percentb
of
HUs
with
Significant
Deteriorated
LBP(%)
HUs
in
Sample
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Interior
Only
2,629
1,692
3,566
3%
2%
4%
28
Both
Interior
and
Exterior
3,487
2,132
4,842
4%
2%
5%
34
Exterior
Only
7,518
5,357
9,679
8%
6%
10%
65
Total
with
Significantly
Deteriorated
LBP
13,634
10,928
16,341
14%
11%
17%
127
No
Significantly
Deteriorated
LBP
82,053
79,347
84,760
86%
83%
89%
704
TOTAL
95,688
100%
831
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
Percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
Percentages
may
not
total
100%
due
to
rounding.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

An
estimated
17
million
(
±
2
million)
or
18
percent
(
±
3%)
of
housing
units
in
the
United
States
have
deteriorated
LBP.
The
deteriorated
LBP
is
only
on
the
exterior
for
approximately
40
percent
of
the
homes
with
deteriorated
LBP.
An
estimated
14
million
(
±
3
million)
or
14
percent
(
±
3%)
of
housing
units
in
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
9
October
31,
2002
the
United
States
have
significantly
deteriorated
LBP.
Roughly
55
percent
of
these
homes
have
significant
deterioration
only
on
exterior
surfaces.
Twenty
percent
of
these
homes
have
the
significantly
deteriorated
LBP
only
on
interior
surfaces.

Table
4.4
presents
the
number
and
percentage
of
housing
units
with
deteriorated
and
significantly
deteriorated
LBP
by
construction
year.
The
data
suggest
that
older
homes
are
more
likely
to
have
deteriorated
LBP
than
newer
homes.
Only
3%
of
homes
built
between
1960
and
1977
have
deteriorated
LBP,
but
the
percentage
increases
to
32%
for
homes
built
between
1940
and
1959,
and
to
56%
for
homes
built
before
1940.

Only
2%
of
homes
built
between
1960
and
1977
have
significantly
deteriorated
LBP,
but
the
percentage
increases
to
25%
for
homes
built
between
1940
and
1959,
and
to
44%
for
homes
built
before
1940.

Table
4.4
Distribution
of
Housing
Units
(
HUs)
with
Deteriorated
and
Significantly
Deteriorated
Lead­
Based
Paint
(
LBP)
by
Construction
Year
Deteriorated
LBP
Construction
Year
Total
HUs
(
000)
b
Number
of
HUs
with
Deteriorated
LBP
(
000)
Percent
of
HUs
with
Deteriorated
LBP
(%)
a
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
1978­
1998
29,774
139
0
330
0%
0%
1%
1960­
1977
27,874
910
235
1,586
3%
1%
6%
1940­
1959
20,564
6,510
4,603
8,418
32%
22%
41%
Before
1940
17,476
9,866
8,111
11,620
56%
46%
66%
Total
HUs
95,688
17,425
15,222
19,628
18%
16%
21%

Significantly
Deteriorated
LBP
Construction
Year
Total
HUs
(
000)
b
No.
of
HUs
with
Significantly
Deteriorated
LBP
(
000)
Percent
of
HUs
with
Significantly
Deteriorated
LBP
(%)
a
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
1978­
1998
29,774
83
0
238
0%
0%
1%
1960­
1977
27,874
610
97
1,122
2%
0%
4%
1940­
1959
20,564
5,190
3,387
6,993
25%
16%
34%
Before
1940
17,476
7,752
6,048
9,456
44%
35%
54%
Total
HUs
95,688
13,635
9,893
16,582
14%
10%
17%

a
Percentages
may
not
total
100%
due
to
rounding.
b
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
10
October
31,
2002
Figure
4.4
is
a
bar
chart
that
summarizes
the
above
survey
data
on
deteriorated
and
significantly
deteriorated
LBP
by
construction
year.
It
graphically
displays
the
downward
trends
in
the
prevalence
of
LBP
in
homes
and
of
damaged
LBP
in
homes.

Figure
4.4.
Presence
and
Condition
of
LBP
by
Construction
Year
­
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
22,000
24,000
26,000
28,000
30,000
32,000
Before
1940
1940­
1959
1960­
1977
1977­
1998
HU
Construction
Year
Number
of
HU's
(
000)
Significant
Deterioration
De
minimis
Deterioration
Undamaged
LBP
No
LBP
4.3
Paint
Lead
Loadings
in
Housing
Table
4.5
presents
the
distribution
of
the
highest
lead
paint
loading
by
location
in
the
building
for
selected
thresholds:
0.3,
0.6,
0.8,
1.0,
1.3,
4.0,
and
10.0
mg/
cm2.
By
definition,
paint
with
less
than
1.0
mg/
cm2
is
not
LBP;
thus,
the
first
four
categories
represent
paint
that
is
considered
not
to
be
LBP.
The
majority
of
the
surfaces
did
not
contain
lead­
based
paint:
in
70
percent
of
HUs
the
highest
interior
readings,

and
in
69
percent
of
HUs
the
highest
exterior
readings,
were
below
1.0
mg/
cm2.
Fourteen
percent
of
HUs
had
at
least
one
paint
sample
with
10
mg/
cm2
or
more
of
lead­
based
paint.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
11
October
31,
2002
Table
4.5
Distribution
of
Paint
Lead
Loading
by
Location
in
the
Building
Maximum
Paint
Interior
(%
HUs)
a
Exterior
(%
HUs)
Anywhere
(%
HUs)

Lead
Loading
in
HUc
Estimate
Lower
95%
CIb
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
GT
0
mg/
cm2
100%
100%
100%
100%
100%

GE
0.3
mg/
cm2
51%
47%
55%
42%
39%
46%
62%
58%
67%

GE
0.6
mg/
cm2
37%
34%
39%
35%
32%
38%
47%
44%
50%

GE
0.8
mg/
cm2
31%
29%
34%
32%
29%
36%
42%
39%
45%

GE
1.0
mg/
cm2
30%
27%
33%
31%
27%
34%
40%
36%
43%

GE
1.3
mg/
cm2
26%
24%
29%
29%
26%
33%
36%
33%
40%

GE
4.0
mg/
cm2
17%
14%
20%
18%
15%
22%
24%
20%
27%

GE
10.0
mg/
cm2
9%
7%
12%
10%
8%
13%
14%
11%
17%

TOTAL
HUs
100%
100%
100%

a
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
c
GT
equals
"
greater
than."
GE
equals
"
greater
than
or
equal
to."

Table
4.6
presents
the
distribution
of
paint
lead
loadings
by
location
in
the
building
and
construction
year
for
the
selected
thresholds.
This
clearly
demonstrates
the
effectiveness
of
the
reduction
from
1940
to
1980
in
the
amount
of
lead
added
to
commercial
residential
paint.
An
estimated
87
percent
of
housing
reported
as
built
before
1940
had
at
least
one
paint
lead
measurement
somewhere
in
the
house
at
1.0
mg/
cm2,

or
above.
This
decreased
to
24
percent
of
housing
reported
as
built
between
1960
and
1977,
and
to
7
percent
of
housing
reported
as
built
since
1978.
The
same
pattern
holds
for
very
high
lead
levels,
with
55
percent
of
pre­
1940
homes
having
some
lead
above
10
mg/
cm2
but
only
1
percent
for
post­
1977
housing.
37
37
It
should
be
noted
that
the
1
percent
of
homes
built
in
1978­
1998
with
a
maximum
paint
lead
loading
above
10.0
mg/
cm2
may
be
a
result
of
respondent
error
in
reporting
the
date
of
home
construction.
The
year
reported
by
the
respondent
was
never
overridden.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
12
October
31,
2002
Table
4.6
Distribution
of
Paint
Lead
Loading
by
Location
in
the
Building
and
Construction
Year
Percent
of
HUs
with
LBPa,
b
Largest
Paint
Lead
Loading
in
the
Housing
Unit
Year
of
Construction
1978­
1998
1960­
1977
1940­
1959
Before
1940
Subtotal
Interior
GT
0
mg/
cm2
100%
100%
100%
100%
100%
GE
0.3
mg/
cm2
23%
39%
77%
91%
51%
GE
0.6
mg/
cm2
9%
21%
59%
83%
37%
GE
0.8
mg/
cm2
6%
16%
48%
80%
31%
GE
1.0
mg/
cm2
4%
16%
46%
79%
30%
GE
1.3
mg/
cm2
3%
12%
41%
72%
26%
GE
4.0
mg/
cm2
1%
6%
19%
60%
17%
GE
10.0
mg/
cm2
1%
2%
7%
38%
9%
Exterior
GT
0
mg/
cm2
100%
100%
100%
100%
100%
GE
0.3
mg/
cm2
11%
31%
69%
81%
42%
GE
0.6
mg/
cm2
7%
18%
64%
76%
35%
GE
0.8
mg/
cm2
4%
16%
61%
73%
32%
GE
1.0
mg/
cm2
3%
13%
59%
72%
31%
GE
1.3
mg/
cm2
3%
11%
56%
71%
29%
GE
4.0
mg/
cm2
0%
6%
28%
56%
18%
GE
10.0
mg/
cm2
0%
2%
10%
41%
10%
Anywhere
in
Building
GT
0
mg/
cm2
100%
100%
100%
100%
100%
GE
0.3
mg/
cm2
30%
57%
89%
95%
62%
GE
0.6
mg/
cm2
15%
31%
80%
89%
47%
GE
0.8
mg/
cm2
10%
26%
70%
88%
42%
GE
1.0
mg/
cm2
7%
24%
69%
87%
40%
GE
1.3
mg/
cm2
5%
18%
65%
84%
36%
GE
4.0
mg/
cm2
1%
10%
34%
73%
24%
GE
10.0
mg/
cm2
1%
3%
14%
55%
14%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
GT
equals
"
greater
than."
GE
equals
"
greater
than
or
equal
to."

Tables
4.7
and
4.8
present
selected
parameters
of
the
distributions
of
paint
lead
loadings
by
interior
and
exterior
component
types.
Tables
4.7
and
4.8
do
not
include
the
geometric
means
and
standard
deviations
because
of
the
large
number
of
zero
XRF
readings.
All
of
the
distributions
in
Tables
4.7
and
4.8
are
right­
skewed
and
cannot
be
fitted
by
normal
distributions.
A
better
model
would
be
the
lognormal
distribution.
Appendix
C
presents
a
discussion
of
fitting
models
to
these
data.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
13
October
31,
2002
Table
4.7
Estimated
Empirical
Distribution
Parameters
of
Paint
Lead
Loadings
by
Interior
Component
Types
Walls,
Floors,
Ceilings
Windows
Doors
Trim
Other
mg/
cm2
mg/
cm2
mg/
cm2
mg/
cm2
mg/
cm2
Arithmetic
Mean
0.2
0.9
0.5
0.5
0.4
Arithmetic
Standard
Deviation
1.5
3.4
2.5
2.3
2.6
25th
Percentile
0.0
0.0
0.0
0.0
0.0
Median
0.0
0.0
0.0
0.0
0.0
75th
Percentile
0.0
0.1
0.0
0.0
0.0
90th
Percentile
0.1
1.3
0.4
0.2
0.2
95th
Percentile
0.3
6.0
1.9
1.4
0.5
Number
of
Readings
14,876
5,513
4,596
2,578
2,686
Table
4.8
Estimated
Empirical
Distribution
Parameters
of
Paint
Lead
Loadings
by
Exterior
Component
Types
Walls
Windows
Doors
Trim
Porch
Other
mg/
cm2
mg/
cm2
mg/
cm2
mg/
cm2
mg/
cm2
mg/
cm2
Arithmetic
Mean
0.9
2.5
1.2
1.1
1.1
1.6
Arithmetic
Standard
Deviation
3.4
6.2
4.4
4.5
3.9
5.1
25th
Percentile
0.0
0.0
0.0
0.0
0.0
0.0
Median
0.0
0.0
0.0
0.0
0.0
0.0
75th
Percentile
0.1
1.7
0.1
0.1
0.1
0.3
90th
Percentile
1.9
7.7
2.4
1.8
2.2
3.3
95th
Percentile
4.8
15.3
7.4
5.4
7.8
10.7
Number
of
Readings
2,008
781
1,398
446
698
250
Table
4.9
summarizes
the
data
on
LBP
by
component
type
from
a
different
perspective;
it
presents
the
percentage
of
components
with
LBP
by
component
type
and
housing
unit
age.
Table
4.9
shows
the
expected
trends
and
differences:
exterior
components
are
more
likely
to
be
leaded
than
interior
components;
interior
walls
are
least
likely
to
have
LBP;
and
older
homes
have
more
LBP
than
newer
homes.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
14
October
31,
2002
Table
4.9
Percentage
of
Components
with
Lead­
Based
Paint
by
Component
Type
and
HU
Age
Component
Type
Year
of
Construction
All
Years
1978­
1998
1960­
1977
1940­
1959
Before
1940
Interior
Walls,
Floors
Ceilings
2%
0%
1%
2%
7%
Windows
9%
1%
2%
6%
21%
Doors
7%
0%
1%
7%
22%
Trim
5%
0%
2%
4%
15%
Other
4%
0%
1%
2%
12%
All
Components
30%
4%
16%
46%
79%

Exterior
Walls
14%
0%
9%
18%
34%
Windows
25%
0%
12%
30%
41%
Doors
15%
2%
5%
29%
33%
Trim
11%
3%
8%
16%
24%
Porch
15%
1%
7%
25%
28%
Other
18%
0%
8%
37%
37%
All
Components
31%
3%
13%
59%
72%

Table
4.10
presents
selected
parameters
of
the
distributions
of
paint
lead
loading
by
interior
rooms
and
for
all
exterior
surfaces.
Paint
lead
loadings
are
higher
on
exterior
surfaces
than
on
interior
surfaces.
Differences
between
average
paint
lead
loadings
in
interior
rooms
are
small
compared
to
differences
between
component
types
within
rooms
(
see
Table
4.7).

Table
4.10
Estimated
Empirical
Distribution
Parameters
of
Paint
Lead
Loadings
by
Room
Type
Kitchen
Living
Room
Bed
Room
Other
Room
Exterior
mg/
cm2
mg/
cm2
mg/
cm2
mg/
cm2
mg/
cm2
Arithmetic
Mean
0.5
0.4
0.4
0.4
1.3
Arithmetic
Standard
Deviation
2.3
2.3
2.3
2.3
4.4
25th
Percentile
0
0
0
0
0
Median
0
0
0
0
0
75th
Percentile
0.1
0
0
0
0.2
90th
Percentile
0.4
0.2
0.2
0.2
2.7
95th
Percentile
1.7
0.8
1
0.8
7.8
Number
of
Readings
7127
7375
8053
7387
5581
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
15
October
31,
2002
4.4
Comparison
of
Prevalence
of
Lead­
Based
Paint
(
LBP)
to
the
1990
LBP
Survey
Table
4.11
compares
the
prevalence
of
LBP
and
deteriorated
LBP
found
in
the
NSLAH
(
restricted
to
pre­
1980
construction)
with
the
prevalence
found
in
the
1990
LBP
Survey,
which
was
similarly
restricted38.
The
NSLAH
shows
fewer
total
homes
built
before
1980.
This
is
partly
due
to
the
fact
that
housing
where
children
could
not
live
was
excluded
from
the
current
survey.
There
has
also
been
a
loss
of
homes
built
before
1980
due
to
demolition.

Table
4.11
Comparison
of
the
Prevalence
of
Lead­
Based
Paint1
to
the
1990
LBP
Survey
1990
LBP
Survey
Current
NSLAH
(
Pre­
1980
HUs)
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
Total
HUs
Built
Before
1980
77,177
100%
68,756
100%
HUs
with
LBP
64,059
83%
34,195
50%
Interior
LBP
48,986
63%
26,184
38%
Exterior
LBP
56,495
73%
27,373
40%
HUs
with
Deteriorated
LBPa
14,354
19%
14,962
22%
Interior
Deteriorated
LBP
5,596
7%
7,281
11%
Exterior
Deteriorated
LBP
9,657
13%
11,784
17%

a
Deteriorated
LBP
is
defined
in
the
1995
HUD
Guidelines
(
Guidelines
for
the
Evaluation
and
Control
of
Lead­
Based
Paint
Hazards
in
Housing,
HUD
1539­
LBP,
Washington,
D.
C.)
for
the
NSLAH,
and
as
5
square
feet
or
more
of
deteriorated
LBP
for
the
1990
survey.

A
lower
percentage
of
pre­
1980
homes
were
found
with
LBP
during
the
current
NSLAH
(
50%

versus
83%
found
in
1990).
This
was
not
unexpected
because
there
has
been
renovation,
remodeling,

demolition,
and
paint
removal
activities
in
the
intervening
years.

The
number
of
homes
with
LBP
was
expected
to
decrease
between
1990
and
1999,
primarily
due
to
demolition,
renovation
and
remodeling
of
older
homes.
For
homes
built
around
the
same
time,
the
percentage
of
homes
with
LBP
was
also
expected
to
decrease
between
1990
and
1999,
primarily
due
to
renovation
and
remodeling
of
older
homes.
However,
the
difference
between
the
1990
and
1999
survey
estimates
of
the
number
and
percentage
of
homes
with
LBP
is
greater
than
might
be
expected
from
these
sources.
Factors
that
might
explain
the
differences
include:


Demolition.
Demolition
of
older
homes
reduces
the
number
of
homes
with
LBP
over
time.

38
A
comparison
of
the
protocols
for
the
two
surveys
is
presented
in
Appendix
B.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
16
October
31,
2002

Renovation,
Remodeling,
and
Remediation.
Removal
of
surfaces
with
LBP
during
renovation
and
remodeling
reduces
both
the
number
and
percentage
of
homes
with
LBP.
Covering
(
encapsulating)
surfaces
with
LBP
reduces
the
quantity
of
lead
directly
accessible
to
occupants
and
reduces
the
XRF
reading
on
the
surface.
The
lower
XRF
readings
result
in
fewer
homes
classified
as
having
LBP.
Although
additional
coats
of
paint
are
expected
to
reduce
XRF
readings,
the
effect
of
painting
is
expected
to
be
small.


XRF
Models.
XRF
measurements
from
the
1999
survey
are
more
precise
than
those
from
the
1990
survey.
The
less
precise
XRF
instrument
used
in
the
1990
survey
was
more
likely
to
misclassify
a
surface
as
having
LBP
and
thus
increases
the
estimated
number
of
surfaces
with
LBP.


XRF
Calibration
Procedures.
The
calibration
of
the
XRF
instrument
used
for
the
1990
survey
was
checked
at
paint
loadings
of
0.6
and
3.0
mg
lead
per
sq.
cm.
The
1990
XRF
readings
were
recalibrated
based
on
these
checks.
The
calibration
of
the
XRF
instrument
used
for
the
1999
survey
was
checked
at
paint
loadings
of
0.0
and
1.0
mg
lead
per
sq.
cm.
The
difference
in
the
calibration
procedures
and
the
assumptions
required
for
the
re­
calibration
of
the
1990
XRF
readings
have
an
unknown
effect
of
the
estimated
number
of
homes
with
LBP.


Sample
Design.
The
two
surveys
used
slightly
different
criteria
and
sampling
methods
for
selecting
the
sampled
homes.
The
primary
difference
being
that
the
1999
survey
excluded
homes
where
children
were
excluded,
some
of
which
may
have
been
included
in
the
1990
survey.


Within­
home
Data
Collection
Procedures.
The
two
surveys
had
different
criteria
and
procedures
for
within­
home
data
collection.
The
1999
survey
collected
measurements
in
more
rooms
within
the
sampled
homes
than
the
1990
survey
(
4
to
6
rooms
vs.
2
rooms).
Within
the
sampled
rooms
the
1999
survey
also
collected
more
measurements.
The
larger
number
of
measurements
in
the
1999
survey
would
tend
to
increase
the
number
of
homes
classified
as
having
LBP,
other
factors
being
equal,
contrary
to
the
observed
decrease.

Approximately
the
same
percentage
of
pre­
1980
homes
with
LBP
had
deteriorated
LBP
in
both
surveys
(
22%
versus
19%
found
in
1990).
The
slight
increase
in
the
percentage
of
homes
with
deteriorated
LBP
was
expected,
because
these
homes
are
now
nine
years
older.
In
addition,
the
definitions
of
deteriorated
LBP
were
different
for
the
two
studies.
In
the
1990
LBP
Survey,
deteriorated
interior
LBP
was
defined
as
more
than
5
square
feet
of
deteriorated
interior
lead­
based
paint,
with
a
similar
definition
for
exterior
leadbased
paint.
Table
4.11
defines
deteriorated
LBP
for
the
NSLAH
according
to
the
1995
Guidelines
(
Guidelines
for
the
Evaluation
and
Control
of
Lead­
Based
Paint
Hazards
in
Housing).
For
these
reasons,
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
17
October
31,
2002
Table
4.11
does
not
attempt
to
present
comparisons
with
respect
to
significantly
deteriorated
LBP;
the
concepts
of
deterioration
above
de
minimis
levels
were
different
in
1990
and
1999.

4.5
Area
of
Lead­
Based
Paint
in
Housing
Table
4.12
presents
estimates
of
the
areas
of
surfaces
with
LBP
by
architectural
component
type.

An
estimated
7.4
billion
square
feet
of
painted
interior
surfaces
are
covered
with
LBP.
This
represents
2
percent
of
the
area
of
painted
interior
surfaces
in
all
homes.
Although
2
percent
of
paint
on
walls,
floors,
and
ceilings
is
lead­
based,
the
area
of
these
LBP­
coated
components
accounts
for
67
percent
of
all
interior
surfaces
with
LBP.
Conversely,
paint
on
window
and
door
system
components
is
more
likely
to
contain
LBP,

but
the
total
surface
area
of
LBP
on
these
components
is
only
21
percent
of
the
area
of
all
interior
painted
surfaces.

An
estimated
29.2
billion
square
feet
of
painted
exterior
surfaces
are
covered
with
LBP.
This
represents
22
percent
of
the
area
of
painted
exterior
surfaces
in
all
homes.
Wall
siding
accounts
for
most
(
67%)
of
the
surface
area
of
LBP.

Although
a
large
number
of
homes
have
LBP,
most
of
them
have
relatively
small
areas
of
LBP.

The
average
home
with
LBP
has
259
square
feet
of
interior
LBP
and
996
square
feet
of
exterior
LBP.
39
39
For
comparison,
a
room
10
feet
by
12
feet
with
an
8
foot
ceiling
has
a
wall
area
of
352
square
feet
and
a
combined
wall,
ceiling
and
floor
area
of
592
square
feet.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
4­
18
October
31,
2002
Table
4.12
Area
of
LBP
by
Painted
Component
Component
National
Total
Amount
of
LBP
Average
Amount
LBP
Per
Housing
Unit
with
LBP
Millions
of
sq.
ft.
Percent
of
All
Paint
on
Component
(
square
feet)

INTERIOR:
Wall,
Floor,
Ceiling
4,993
2%
173
Window
687
9%
24
Door
911
6%
32
Trim
499
5%
17
Cabinets,
Chimney,
Beams
388
2%
13
TOTAL
7,448
2%
259
EXTERIOR:
Wall
26,706
18%
912
Window
365
28%
12
Door
446
14%
15
Trim
556
12%
19
Porch
1,086
21%
37
TOTAL
29,159
22%
996
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
1
October
31,
2002
5.
DUST
LEAD
IN
HOUSING
Chapter
5
presents
estimates
of
the
prevalence
of
lead­
contaminated
dust
in
housing,
including
the
dust
lead
loadings
and
the
association
between
interior
dust
lead
and
exterior
LBP
condition.
No
comparison
is
made
with
the
dust
lead
findings
of
the
1990
LBP
Survey
because
the
vacuum
technique
employed
in
the
earlier
study
is
not
comparable
to
the
wipe
technique
used
in
the
NSLAH.

5.1
Prevalence
of
Dust
Lead
in
Housing
Table
5.1
presents
the
prevalence
of
all
homes
and
homes
with
one
or
more
children
under
6
years
of
age
with
a
dust
lead
hazard
somewhere
in
the
home,
40
as
defined
by
the
HUD
Lead
Safe
Housing
Rule
(
24
CFR
35
Subparts
B­
R).
The
HUD
Lead
Safe
Housing
Rule
defines
a
dust
lead
hazard
as
greater
than
or
equal
to
40
µ
g/
ft2
lead
on
floors
or
250
µ
g/
ft2
lead
on
window
sills.
There
is
no
longer
a
hazard
level
defined
for
dust
lead
on
window
troughs.
The
earlier
HUD
1995
Guidelines
considered
lead
in
dust
to
be
a
hazard
when
dust
on
floors
had
greater
than
100
µ
g/
ft2
lead,
dust
on
window
sills
had
greater
than
500
µ
g/
ft2
lead,
or
dust
on
window
troughs
had
greater
than
800
µ
g/
ft2
lead.
As
discussed
in
Section
3.1
a
housing
unit
is
considered
to
have
a
dust
lead
hazard
if
a
dust
lead
hazard
exists
at
any
of
the
sampled
locations
in
the
housing
unit.
In
contrast,
the
EPA
Lead
Hazards
Identification
Rule
considers
a
housing
unit
to
have
a
dust
lead
hazard
if
the
average
of
the
samples
exceeds
the
relevant
Using
the
HUD
Lead
Safe
Housing
Rule
definition
of
dust
lead
hazard,
an
estimated
16
percent
(+
2%
41)
of
all
homes
have
a
dust
lead
hazard
somewhere
in
the
home,
and
3
percent
(+
1%)
of
all
homes
have
both
a
child
under
6
years
of
age
and
a
dust
lead
hazard.

Figures
5.1
and
5.2
present
the
percentage
of
homes
with
dust
lead
hazards
by
surface
 
floor
and
window
sill
 
and
by
housing
unit
age
and
household
income.
The
expected
gradient
with
housing
unit
age
is
seen
in
Figure
5.1.
Both
figures
show
that
window
sills
have
the
greater
prevalence
of
dust
lead
hazards.

40
The
maximum
lead
dust
loading
on
any
surface
tested
(
floor,
window
sill,
and
window
trough)
in
the
home
was
used
to
determine
whether
a
dust
lead
hazard
existed.

41
All
confidence
intervals
are
at
the
95
percent
level
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
2
October
31,
2002
Table
5.1
Prevalence
of
Housing
Units
with
a
Dust
Lead
Hazard
Somewhere
in
the
Home
HU
Categorya
Number
of
HUs
(
000)
Percent
of
HUs(%)
b
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
HUs
with
Lead
Dust
Hazard
15,468
12,982
17,954
16%
14%
19%
HUs
with
Children
Under
6
Years
and
Lead
Dust
Hazard
2,634
1,586
3,682
16%
11%
20%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
or
HUs
with
resident
children
under
age
6
(
16,402)
as
the
denominator.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

Figure
5.1
Dust
Lead
Hazards
by
Construction
Year
0
5
10
15
20
25
30
35
40
45
Floor
Window
Sill
HUs
(%)
Average
<
1940
1940­
59
1960­
77
1978­
98
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
3
October
31,
2002
Figure
5.2
Dust
Lead
Hazards
by
Household
Income
5.2
Dust
Lead
Loadings
in
Housing
Figures
5.3
and
5.4
present
the
distribution
of
maximum
(
within
housing
unit)
dust
lead
loadings
on
floors
and
window
as
histograms.
Tables
5.2
and
5.3
present
information
on
maximum
and
average
dust
loadings,
respectively,
by
surface.

Table
5.2
presents
the
distribution
of
maximum
dust
lead
loadings
by
surface
(
floor,
window
sill,

and
window
trough)
for
all
U.
S.
homes
in
the
target
population,
for
selected
threshold
values.
As
with
Table
5.1,
the
estimates
are
based
on
the
maximum
dust
lead
loading
in
the
home
for
the
particular
surface.

Only
an
estimated
6
percent
of
all
homes
have
maximum
floor
dust
lead
loadings
above
the
HUD
Lead
Safe
Housing
Rule
standard
of
40
µ
g/
ft2.42
More
homes
have
a
window
sill
lead
dust
hazard
than
have
a
floor
dust
hazard.
An
estimated
14
percent
of
all
homes
have
sill
dust
lead
loadings
above
the
HUD
Lead
Safe
Housing
Rule
standard
hazard
of
250
µ
g/
ft2.43
42
The
average
analytical
detection
limit
for
each
wipe
sample
was
3.5
µ
g.
While
detection
limits
for
each
surface
are
area
dependent,
this
corresponds
to
a
detection
limit
of
3.5
µ
g/
ft2
for
a
one
square
foot
floor
sample,
7
µ
g/
ft2
for
a
typical
3
inch
by
24
inch
sill
sample,
or
8
µ
g/
ft2
for
a
typical
1
inch
by
18
inch
trough
sample.

43
From
Table
5.2a,
the
percent
of
homes
with
sill
dust
loadings
above
250
µ
g/
ft2
equals
[
100%
(
all
homes)
­
82%
(
homes
with
lead
in
sill
dust
below
250
µ
g/
ft2)
­
2%
(
homes
with
missing
data)
­
2%
(
homes
with
no
sills)]
=
14%.
0
5
10
15
20
25
Floor
Window
Sill
HUs
(%)
<$
30K/
Year
>=$
30K/
Year
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
4
October
31,
2002
Figure
5.3
Distribution
of
Maximum
Floor
Dust
Lead
Loadings
Figure
5.4
Distribution
of
Maximum
Window
Sill
Dust
Loadings
0
10
20
30
40
50
<
LOD
LOD­
5
5­
10
10­
20
20­
40
40­
100
>
100
Dust
Lead
Loadings
(
µ
g/
sq
ft)
HUs
(%)

0
10
20
30
40
50
60
70
<
LOD
LOD­
125
125­
250
250­
500
>
500
Dust
Lead
Loadings
(
µ
g/
sq
ft)
HUs
(%)
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
5
October
31,
2002
Table
5.2
Distribution
of
Maximum
Dust
Lead
Loadings
in
Housing
Units
by
Surface
Maximum
Dust
Lead
Loading
in
HU
(
µ
g/
sq
ft)
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Estimate
Lower
95%
CId
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Floors:
c
LT
LODe
38,369
34,302
42,436
40%
36%
44%
GE
LOD
57,196
53,147
61,244
60%
56%
64%
GE
5
28,200
24,920
31,481
30%
26%
33%
GE
10
15,964
13,141
18,787
17%
14%
20%
GE
20
8,989
6,871
11,108
9%
7%
12%
GE
40
5,495
3,770
7,220
6%
4%
8%
GE
100
2,426
1,470
3,382
3%
2%
4%
Missingf
123
0%

Window
Sills:
LT
LOD
9,602
7,326
11,879
10%
8%
13%
GE
LOD
82,134
78,850
85,418
86%
83%
88%
GE
125
20,338
17,590
23,085
21%
19%
24%
GE
250
13,439
11,516
15,362
14%
12%
16%
GE
500
9,042
7,136
10,949
10%
8%
12%
No
sill
present
in
HUg
2,221
848
3,594
2%
1%
4%
Missingf
1,731
2%

Window
Troughs:
LT
LOD
374
0
799
0%
0%
1%
GE
LOD
72,638
67,107
78,169
76%
70%
82%
GE
800
21,210
16,489
25,931
22%
17%
27%
No
trough
present
in
HU
7,318
5,176
9,459
8%
5%
10%
Missingf
15,358
16%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
c
Floors
include
both
carpeted
and
uncarpeted
floors.
d
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
e
LT
equals
"
less
than."
GE
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
f
Missing
means
that
the
floor,
sill,
or
trough
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
g
No
sill/
trough
present"
means
that
there
was
no
sill
or
trough
in
the
HU,
e.
g.,
windows
were
flush
with
the
wall,
or
awning
windows
were
installed.

Table
5.3
presents
the
distribution
of
average
dust
lead
loadings
by
surface
(
floor,
window
sill,

and
window
trough)
for
all
U.
S.
homes
in
the
target
population,
for
selected
threshold
values.
The
average
dust
loading
for
each
surface
was
determined
by
simply
adding
floor,
window
sill,
or
window
trough
dust
National
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Final
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I
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6
October
31,
2002
loadings
for
each
room
sampled
in
each
HU
and
dividing
by
the
number
of
rooms
sampled
(
unweighted
average).
44
The
same
trends
are
observed
in
Table
5.3
for
average
dust
lead
loadings
as
for
the
distribution
of
maximum
dust
lead
loadings
in
Table
5.2.
However,
Table
5.3
shows
that
fewer
homes
have
carpeted
floor
dust
lead
hazards
than
uncarpeted
floor
dust
hazards
(
i.
e.,
carpeted
floors
have
lower
dust
lead
loadings
 
as
indicated
by
the
results
of
the
wipe
sampling
employed
in
the
survey).
In
fact,
the
regression
modeling
suggested
that
lead
loadings
on
carpeted
surfaces
were
approximately
25
percent
lower
than
smooth
and
cleanable
surfaces
and
75
percent
lower
than
uncarpeted
surfaces
that
were
not
smooth
and
cleanable
(
see
Figure
C.
7)
45
44
For
averaging
floor
samples,
only
carpeted
floor
samples
and
uncarpeted
floor
samples
were
combined
for
the
respective
average
(
carpeted
or
uncarpeted).

45
The
regression
modeling
also
suggested
that
homes
with
no
evidence
of
cleaning
had
higher
floor
and
window
dust
lead
loadings
(
see
Figure
C.
7
and
Figure
C.
9).
Higher
window
dust
lead
loadings
were
suggested
for
rented
homes
as
compared
to
owned
homes,
surfaces
that
were
not
smooth
and
cleanable
as
compared
to
smooth
surfaces,
and
windows
with
vinyl
mini­
blinds
as
compared
to
those
without
vinyl
mini­
blinds
(
see
Figure
C.
9).
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
7
October
31,
2002
Table
5.3
Distribution
of
Average
Dust
Lead
Loadings
in
Housing
Units
by
Surface
Average
Dust
Lead
Loading
in
HU
(
µ
g/
sq
ft)
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Floors
(
Uncarpeted):

LT
LODd
51,252
47,180
55,323
54%
49%
58%
GE
LOD
40,529
36,366
44,693
42%
38%
47%
GE
5
17,291
13,855
20,727
18%
14%
22%
GE
10
8,512
6,348
10,676
9%
7%
11%
GE
20
4,843
3,263
6,423
5%
3%
7%
GE
40
2,449
1,414
3,484
3%
2%
4%
GE
100
966
239
1,694
1%
0%
2%
No
Uncarpeted
3,907
4%
Floors
(
Carpeted):
LT
LODd
66,628
63,563
69,694
70%
67%
73%
GE
LOD
21,356
18,700
24,012
22%
20%
25%
GE
5
5,806
4,073
7,540
6%
4%
8%
GE
10
2,374
1,488
3,261
3%
2%
3%
GE
20
1,368
674
2,061
1%
1%
2%
GE
40
298
0
634
0%
0%
1%
GE
100
59
0
190
0%
0%
0%
No
Carpeted
7,704
8%
Window
Sills:
LT
LOD
12,800
10,201
15,399
13%
11%
16%
GE
LOD
78,936
75,462
82,410
83%
80%
85%
GE
125
13,875
11,717
16,033
15%
12%
17%
GE
250
8,287
6,636
9,938
9%
7%
10%
GE
500
4,900
3,611
6,190
5%
4%
7%
No
sill
present
in
HUe
2,221
848
3,594
2%
1%
4%
Missingf
1,731
2%
Window
Troughs:
LT
LOD
663
52
1,274
1%
0%
1%
GE
LOD
72,349
66,714
77,985
76%
70%
81%
GE
800
16,395
12,827
19,964
17%
13%
21%
No
trough
present
in
HU
7,318
5,176
9,459
8%
5%
10%
Missing
15,358
16%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
d
LT
equals
"
less
than."
GT
equals
"
greater
than."
LOD
equals
"
limit
of
detection."
e
"
No
sill/
trough
present"
means
that
there
was
no
sill
or
trough
in
the
HU,
e.
g.,
windows
were
flush
with
the
wall,
or
awning
windows
were
installed.
f
Missing
means
that
the
floor,
sill,
or
trough
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
8
October
31,
2002
Table
5.4
presents
the
distribution
of
dust
lead
loadings
by
room
type
and
surface
for
selected
threshold
values.
The
vast
majority
of
floors
had
undetectable
levels
of
dust
lead.
About
1
percent
of
rooms
had
dust
lead
levels
above
the
HUD
Lead
Safe
Housing
Rule
standard
for
floors.
Five
percent
of
rooms
had
dust
lead
levels
above
the
HUD
Lead
Safe
Housing
Rule
standard
for
window
sills.

Figure
5.5
presents
a
scatter
plot
of
the
window
sill
dust
lead
loadings
against
the
floor
dust
lead
loadings.
Each
point
in
Figure
5.5
represents
the
floor
and
window
dust
lead
loadings
from
the
same
room
in
the
same
housing
unit.
The
figure
shows
evidence
of
a
moderate
positive
correlation
between
the
dust
lead
loadings
on
these
two
neighboring
surfaces.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
9
October
31,
2002
Table
5.4
Distribution
of
Dust
Lead
Loading
by
Room
and
Surfaces
Dust
Lead
Kitchens
Living
Rooms
Bedrooms
Other
Rooms
Loading
(
µ
g/
sq
ft)
a
Number
of
Rooms
(
000)
b
Percent
of
Rooms
(%)
c
Number
of
Rooms
(
000)
Percent
of
Rooms
(%)
Number
of
Rooms
(
000)
Percent
of
Rooms
(%)
Number
of
Rooms
(
000)
Percent
of
Rooms
(%)
Floorsd
LT
LODe
63,244
66%
98,433
78%
170,153
78%
231,924
73%
GE
LOD
31,633
33%
26,732
21%
45,915
21%
84,438
27%
GE
5
14,062
15%
9,863
8%
19,340
9%
34,291
11%
GE
10
5,568
6%
4,287
3%
10,612
5%
18,933
6%
GE
20
2,571
3%
1,824
1%
4,175
2%
10,626
3%
GE
40
712
1%
880
1%
1,593
1%
7,477
2%
GE
100
335
0%
170
0%
1,354
1%
785
0%
Missingf
488
1%
1,737
1%
1,002
1%
2,594
1%
Total
Rooms
95,365
100%
126,902
100%
217,069
100%
318,956
100%
Window
Sills
LT
LOD
23,001
24%
29,378
23%
38,394
18%
44,841
14%
GE
LOD
50,393
53%
72,154
57%
140,748
65%
141,008
44%
GE
125
7,037
7%
10,937
9%
20,393
9%
23,472
7%
GE
250
4,329
5%
6,731
5%
11,075
5%
17,156
5%
GE
500
2,455
3%
4,386
4%
6,661
3%
10,096
3%
Missing
3,870
4%
5,462
4%
17,993
8%
16,321
5%
No
Sills
18,102
19%
19,907
16%
19,934
9%
116,785
37%
Total
Rooms
95,365
100%
126,902
100%
217,069
100%
318,956
100%
Window
Troughs
LT
LOD
3,293
4%
4,125
3%
5,211
2%
6,657
2%
GE
LOD
49,962
52%
64,827
51%
122,752
57%
119,236
37%
GE
800
9,249
10%
12,795
10%
23,268
11%
21,487
7%
Missing
16,542
17%
27,537
22%
57,738
27%
58,044
18%
No
Trough
25,568
27%
30,413
24%
31,368
15%
135,019
42%
Total
Rooms
95,365
100%
126,902
100%
217,069
100%
318,956
100%

a
In
this
table,
maximum
loading
is
not
applicable
as
only
one
dust
sample
was
collected
from
each
surface
in
each
room.
v
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
c
All
percentages
are
calculated
with
total
rooms
of
that
type
as
the
denominator.
d
Floors
include
both
carpeted
and
uncarpeted
floors.
e
LT
equals
"
less
than."
GE
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
f
Missing
means
that
the
floor,
sill,
or
trough
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
10
October
31,
2002
Figure
5.5
Association
Between
Dust
Lead
Loading
on
Floors
and
Window
Sills
Tables
5.5a
through
5.5c
present
the
distributions
of
floor,
window
sill,
and
window
trough
dust
lead
loadings,
respectively,
by
selected
thresholds
and
by
year
of
construction.
It
is
evident
that
older
homes
have
considerably
more
dust
lead
than
newer
homes.
The
percentage
of
homes
over
the
HUD
Rule
standard
of
40
µ
g/
ft2
for
floor
dust
(
Table
5.5a)
increases
from
less
than
1
percent
for
post­
1977
homes
to
16
percent
0.01
0.1
1
10
100
1000
10000
100000
0.1
1
10
100
1000
10000
100000
Floor
Lead
Loading
(
µ
g/
sq
ft)
Window
Sill
Lead
Loading
(
µ
g/
sq
ft)
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
11
October
31,
2002
for
pre­
1940
homes.
The
percentage
of
homes
over
the
sill
dust
standard
(
Table
5.5b)
steadily
increases
from
4
percent
for
post­
1977
homes
to
14
percent
for
1940­
1959
homes
to
40
percent
for
pre­
1940
homes.

Table
5.5a
Maximum
Floor
Dust
Lead
Loading
by
Year
of
Construction
Maximum
Floor
Dust
Year
of
Construction
Lead
Loading(
µ
g/
sq
ft)
a
1978­
1998
1960­
1977
1940­
1959
Before
1940
Number
(
000)
Percent
(%)
b
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
LT
LODc
Number
HUsd
17,487
59%
13,006
47%
5,667
28%
2,208
13%
Lower
95%
CIe
15,646
53%
10,272
38%
4,076
20%
782
4%
Upper
95%
CI
19,329
65%
15,740
56%
7,257
35%
3,635
21%

GE
LOD
Number
HUs
12,241
41%
14,868
53%
14,820
72%
15,268
87%
Lower
95%
CI
10,419
35%
12,454
44%
12,770
65%
13,008
79%
Upper
95%
CI
14,064
47%
17,281
62%
16,869
80%
17,527
96%

GE
5
Number
HUs
3,233
11%
4,968
18%
8,753
43%
11,245
64%
Lower
95%
CI
2,285
8%
3,567
13%
7,060
35%
9,635
55%
Upper
95%
CI
4,181
14%
6,370
23%
10,446
50%
12,855
73%

GE
10
Number
HUs
1,153
4%
2,488
9%
4,938
24%
7,386
42%
Lower
95%
CI
370
1%
1,607
6%
3,447
17%
5,802
33%
Upper
95%
CI
1,935
7%
3,369
12%
6,428
31%
8,970
52%

GE
20
Number
HUs
97
0%
1,112
4%
2,784
14%
4,996
29%
Lower
95%
CI
0
0%
516
2%
1,283
6%
3,759
22%
Upper
95%
CI
267
1%
1,708
6%
4,286
21%
6,234
35%

GE
40
Number
HUs
97
0%
588
2%
1,967
10%
2,843
16%
Lower
95%
CI
0
0%
216
1%
718
4%
1,989
11%
Upper
95%
CI
267
1%
961
4%
3,215
16%
3,698
21%

GE
100
Number
HUs
97
0%
280
1%
935
5%
1,114
6%
Lower
95%
CI
0
0%
0
0%
121
1%
587
3%
Upper
95%
CI
267
1%
640
2%
1,750
9%
1,642
9%

Missing
Number
HUs
0
0%
0
0%
77
0%
0
0%

a
Floors
include
both
carpeted
and
uncarpeted
floors.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.

c
LT
equals
"
less
than."
GE
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
e
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
12
October
31,
2002
Table
5.5b
Maximum
Window
Sill
Dust
Lead
Loading
by
Year
of
Construction
Maximum
Floor
Dust
Year
of
Construction
Lead
Loading(
µ
g/
sq
ft)
a
1978­
1998
1960­
1977
1940­
1959
Before
1940
Number
(
000)
Percent
(%)
b
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
LT
LODc
Number
HUsd
6,196
21%
1,924
7%
1,074
5%
408
2%
Lower
95%
CIe
4,270
14%
826
3%
277
1%
0
0%
Upper
95%
CI
8,122
27%
3,021
11%
1,871
9%
835
5%

GE
LOD
Number
HUs
21,823
73%
24,729
89%
18,779
91%
16,803
96%
Lower
95%
CI
19,833
68%
22,996
84%
16,956
87%
15,103
93%
Upper
95%
CI
23,814
79%
26,462
94%
20,602
96%
18,503
99%

GE
125
Number
HUs
1,806
6%
4,097
15%
5,407
26%
9,028
52%
Lower
95%
CI
578
2%
2,444
9%
3,954
19%
7,196
42%
Upper
95%
CI
3,033
10%
5,749
21%
6,860
33%
10,861
61%

GE
250
Number
HUs
1,029
4%
1,755
6%
3,712
18%
6,943
40%
Lower
95%
CI
139
1%
1,086
4%
2,556
12%
5,476
31%
Upper
95%
CI
1,919
7%
2,424
9%
4,867
24%
8,410
48%

GE
500
Number
HUs
447
2%
747
3%
2,869
14%
4,980
29%
Lower
95%
CI
0
0%
274
1%
1,779
9%
3,712
21%
Upper
95%
CI
1,024
3%
1,219
4%
3,959
19%
6,247
36%

Missing
Number
HUs
299
1%
851
3%
361
2%
220
1%
No
sills
Number
HUs
1,456
5%
371
1%
349
2%
45
0%
Lower
95%
CI
456
2%
0
0%
0
0%
0
0%
Upper
95%
CI
2,456
8%
762
3%
730
4%
143
1%

a
Missing
means
that
the
sill
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
"
No
sill
present"
means
that
there
was
no
sill
in
the
HU,
e.
g.,
windows
were
flush
with
the
wall,
or
awning
windows
were
installed.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.

c
LT
equals
"
less
than."
GT
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
e
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
13
October
31,
2002
Table
5.5c
Maximum
Window
Trough
Dust
Lead
Loading
by
Year
of
Construction
Year
of
Construction
1978­
1998
1960­
1977
1940­
1959
Before
1940
Maximum
Window
Trough
Dust
Lead
Loading
(
µ
g/
sq
ft)
a
Number
(
000)
Percent
(%)
b
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)

LT
LODc
Number
HUsd
280
1%
94
0%
0
0%
0
0%
Lower
95%
CIe
0
0%
0
0%
0
0%
0
0%

Upper
95%
CI
681
2%
235
1%
0
0%
0
0%

GE
LOD
Number
HUs
20,969
70%
20,319
73%
16,406
80%
14,943
86%
Lower
95%
CI
17,718
60%
17,730
64%
14,638
73%
13,192
80%

Upper
95%
CI
24,221
81%
22,909
82%
18,174
86%
16,694
91%

GE
800
Number
HUs
2,252
8%
3,788
14%
6,286
31%
8,883
51%
Lower
95%
CI
1,032
4%
2,504
9%
4,500
21%
7,084
41%

Upper
95%
CI
3,473
12%
5,072
18%
8,073
40%
10,683
61%

Missing
Number
HUs
4,184
14%
5,885
21%
2,966
14%
2,322
13%
No
troughs
Number
HUs
4,341
15%
1,576
6%
1,191
6%
210
1%
Lower
95%
CI
2,380
8%
732
3%
368
2%
0
0%

Upper
95%
CI
6,301
21%
2,419
9%
2,014
10%
451
3%

a
Missing
means
that
the
trough
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
"
No
trough
present"
means
that
there
was
no
trough
in
the
HU,
e.
g.,
windows
were
flush
with
the
wall,
or
awning
windows
were
installed.
b
All
percentages
are
calculated
with
total
housing
units
of
that
age
as
the
denominator.

c
LT
equals
"
less
than."
GT
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live
e
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

Tables
5.6a
through
5.6c
present
floor,
window
sill,
and
window
trough
dust
loading
distributions
by
household
income
level.
There
are
some
significant
differences
shown
in
the
table.
A
greater
percent
of
homes
in
the
higher
income
level
have
lower
lead
dust
loadings.
For
example,
47
percent
of
higher
income
homes
have
lead
dust
loadings
on
floors
below
the
limit
of
detection,
while
only
29
percent
of
homes
in
the
lower
income
level
have
loadings
below
the
limit
of
detection.
Only
1
percent
of
homes
in
the
higher
household
income
level
exceed
100
µ
g/
ft2
floor
dust
lead
loading,
while
5
percent
of
lower
income
level
homes
exceed
this
loading.
Similar
trends
are
observed
for
window
sill
and
trough
dust
loadings.

Although
the
data
have
not
been
presented,
there
were
no
apparent
differences
between
urbanization
categories
and
dust
lead
loadings.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
14
October
31,
2002
Table
5.6a
Maximum
Floor
Dust
Lead
Loadings
by
Household
Income
Maximum
Floor
Dust
Lead
Loading(
µ
g/
sq
ft)
a
Household
Income
Less
than
$
30,000/
year
Equal
to
or
above
$
30,000/
year
Number
(
000)
Percent
(%)
b
Number
(
000)
Percent
(%)

LT
LODc
Number
HUsd
9,747
29%
26,508
47%
Lower
95%
CIe
6,944
23%
22,360
42%

Upper
95%
CI
12,550
35%
30,657
53%

GE
LOD
Number
HUs
24,038
71%
29,525
53%
Lower
95%
CI
19,932
65%
26,065
47%

Upper
95%
CI
28,143
77%
32,985
58%

GE
5
Number
HUs
13,364
40%
13,215
24%
Lower
95%
CI
10,562
32%
10,859
20%

Upper
95%
CI
16,166
47%
15,571
27%

GE
10
Number
HUs
8,276
25%
6,792
12%
Lower
95%
CI
6,219
19%
5,052
9%

Upper
95%
CI
10,332
30%
8,532
15%

GE
20
Number
HUs
4,282
13%
4,135
7%
Lower
95%
CI
3,117
9%
2,782
5%

Upper
95%
CI
5,447
17%
5,488
10%

GE
40
Number
HUs
2,819
8%
2,170
4%
Lower
95%
CI
1,710
5%
924
2%

Upper
95%
CI
3,927
12%
3,415
6%

GE
100
Number
HUs
1,637
5%
435
1%
Lower
95%
CI
728
2%
57
0%

Upper
95%
CI
2,546
8%
813
1%

Missing
Number
HUs
46
0%
77
0%

a
Missing
means
that
the
sill
or
trough
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
b
All
percentages
are
calculated
with
total
housing
units
in
that
income
class
as
the
denominator.

c
LT
equals
"
less
than."
GT
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
e
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
15
October
31,
2002
Table
5.6b
Maximum
Window
Sill
Lead
Dust
Loadings
by
Household
Income
Household
Income
Less
than
$
30,000/
year
Equal
to
or
Above
$
30,000/
year
Window
Sill
Dust
Lead
Loading(
µ
g/
sq
ft)
a
Number
(
000)
Percentb
Number
(
000)
Percent
LT
LODc
Number
HUsd
1,448
4%
7,111
13%
Lower
95%
CIe
376
1%
5,291
9%

Upper
95%
CI
2,520
7%
8,931
16%

GE
LOD
Number
HUs
29,948
89%
47,597
85%
Lower
95%
CI
24,656
84%
42,665
81%

Upper
95%
CI
35,241
93%
52,528
89%

GE
125
Number
HUs
10,322
31%
8,865
16%
Lower
95%
CI
7,909
26%
6,896
13%

Upper
95%
CI
12,735
36%
10,835
19%

GE
250
Number
HUs
7,671
23%
4,772
9%
Lower
95%
CI
5,776
18%
3,611
7%

Upper
95%
CI
9,565
28%
5,933
11%

GE
500
Number
HUs
4,395
13%
3,893
7%
Lower
95%
CI
2,943
9%
2,773
5%

Upper
95%
CI
5,846
17%
5,014
9%

Missing
Number
HUs
1,137
3%
594
1%
No
sills
Number
HUs
1,297
4%
809
1%
Lower
95%
CI
250
1%
151
0%

Upper
95%
CI
2,345
7%
1,466
3%

a
Missing
means
that
the
sill
or
trough
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
"
No
sill/
trough
present"
means
that
there
was
no
sill
or
trough
in
the
HU,
e.
g.,
windows
were
flush
with
the
wall,
or
awning
windows
were
installed.
b
All
percentages
are
calculated
with
total
housing
units
in
that
income
class
as
the
denominator.

c
LT
equals
"
less
than."
GT
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
e
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
16
October
31,
2002
Table
5.6c
Maximum
Window
Trough
Lead
Dust
Loadings
by
Household
Income
Maximum
Window
Trough
Dust
Lead
Loading(
µ
g/
sq
ft)
a
Household
Income
Less
than
$
30,000/
year
Equal
to
or
Above
$
30,000/
year
Number
(
000)
Percentb
Number
(
000)
Percent
LT
LODc
Number
HUsd
59
0%
315
1%
Lower
95%
CIe
0
0%
0
0%

Upper
95%
CI
180
1%
723
1%

LT
800
Number
HUs
25,985
77%
42,253
75%
Lower
95%
CI
21,486
70%
37,300
69%

Upper
95%
CI
30,485
84%
47,205
81%

GE
800
Number
HUs
9,449
28%
10,623
19%
Lower
95%
CI
6,742
20%
8,067
15%

Upper
95%
CI
12,156
36%
13,179
23%

Missing
Number
HUs
5,624
17%
8,788
16%
No
troughs
Number
of
HUs
2,162
6%
4,755
9%
Lower
95%
CI
869
3%
3,009
5%

Upper
95%
CI
3,456
10%
6,501
12%

a
Missing
means
that
the
sill
or
trough
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
"
No
sill/
trough
present"
means
that
there
was
no
sill
or
trough
in
the
HU,
e.
g.,
windows
were
flush
with
the
wall,
or
awning
windows
were
installed.
b
All
percentages
are
calculated
with
total
housing
units
in
that
income
class
as
the
denominator.

c
LT
equals
"
less
than.
"
GE
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."

d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.

e
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

Figure
5.646
shows
the
distribution
of
the
dust
lead
loadings
by
room
type:
kitchen,
common
living
area,
bedroom,
and
other
room.
For
these
four
room
types,
both
floor
dust
and
window
dust
have
been
combined.
Dust
loadings
for
the
main
entrance
are
also
shown
in
the
figure,
but
these
are
only
floor
loadings
since
no
data
were
collected
from
main
entrance
windows.
Figure
5.7
shows
the
distribution
of
the
dust
lead
measurements
by
surface
and
carpet.
In
both
figures,
the
distributions
are
extremely
right­
skewed.
Except
for
troughs,
none
of
the
boxes
extend
above
40
µ
g/
ft2,
which
means
that
the
75th
percentile
is
less
than
40
µ
g/
ft2.

However,
there
are
dust
lead
loadings
well
above
10,000
µ
g/
ft2.
On
troughs,
they
extend
above
100,000
µ
g/
ft2.

Table
5.7
presents
selected
parameters
of
the
distributions
of
dust
lead
loadings
by
surface
types,

corresponding
to
the
boxplots
in
Figure
5.7.
Table
5.7
also
presents
geometric
means
and
standard
deviations.

46
Dust
lead
loading
data
is
presented
in
box
plot
form.
Each
box
plot
shows
a
univariate
data
distribution,
for
example,
the
dust
samples
collected
from
a
specific
location
(
e.
g.,
entrance
floor).
The
box
in
the
box
plot
represents
the
middle
50
percent
of
the
data;
the
bottom
of
the
box
gives
the
25th
percentile;
the
top
of
the
box
gives
the
75th
percentile,
and
the
horizontal
line
inside
the
box
gives
the
median
or
50th
percentile.
The
vertical
lines
extending
from
the
top
and
bottom
of
the
box
reach
to
the
largest
and
smallest
observations,
respectively,
except
for
outliers.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
17
October
31,
2002
The
distributions
in
Table
5.7
are
all
right­
skewed,
so
that
they
are
not
normally
distributed.
A
better
model
would
be
the
lognormal
distribution.
Appendix
C
includes
a
discussion
of
distributional
models
for
these
data.

Figure
5.6
Box
Plots
for
Dust
Lead
Loadings
by
Room
a
The
first
four
plots
include
floor
and
window
loadings.
Main
entrance
only
includes
floors
since
no
data
were
collected
from
main
entrance
windows.

b
The
box
in
the
box
plot
represents
the
middle
50
percent
of
the
data;
the
bottom
of
the
box
gives
the
25th
percentile;
the
top
of
the
box
gives
the
75th
percentile,
and
the
horizontal
line
inside
the
box
gives
the
median
or
50th
percentile.
The
vertical
lines
extending
from
the
top
and
bottom
of
the
box
reach
to
the
largest
and
smallest
observations,
respectively,
except
for
outliers.
0.01
0.1
1
10
100
1000
10000
100000
1000000
Kitchen
Living
Room
Bedroom
Other
Room
Main
Entrance
(
Only
Floors)

Room
Type
Dust
Lead
Loading
(
µ
g/
sq
ft)
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
18
October
31,
2002
Figure
5.7
Box
Plots
for
Dust
Lead
Loadings
by
Surface
a
The
box
in
the
box
plot
represents
the
middle
50
percent
of
the
data;
the
bottom
of
the
box
gives
the
25th
percentile;
the
top
of
the
box
gives
the
75th
percentile,
and
the
horizontal
line
inside
the
box
gives
the
median
or
50th
percentile.
The
vertical
lines
extending
from
the
top
and
bottom
of
the
box
reach
to
the
largest
and
smallest
observations,
respectively,
except
for
outliers.
0.01
0.1
1
10
100
1000
10000
100000
1000000
All
Floors
Carpeted
Floors
Non­
Carpeted
Floors
Window
Sills
Window
Troughs
Surface
Dust
Lead
Loading
(
µ
g/
sg
ft)
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
19
October
31,
2002
Table
5.7
Estimated
Empirical
Distribution
Parameters
of
Dust
Lead
Loadings
by
Surface
Types
Floors
Window
Sills
Window
Troughs
µ
g/
ft2
µ
g/
ft2
µ
g/
ft2
Arithmetic
Mean
13.6
194.9
1,990.9
Arithmetic
Standard
Deviation
483.5
1682.7
12,086.5
Geometric
Mean
1.1
9.4
96.4
Geometric
Standard
Deviationa
3.8
9.3
14.4
25th
Percentile
.375
2.0
18.0
Median
0.9
8.3
89.1
75th
Percentile
2.0
37.13
462.0
90th
Percentile
6.0
172.8
2,824.2
95th
Percentile
13.2
524.9
6,974.6
Number
of
Samples
3,894
2,302
1,607
a
The
geometric
standard
deviation
is
computed
as
exp(
s),
where
s
is
the
arithmetic
standard
deviation
of
the
natural
logarithms
of
the
loadings
(
see,
e.
g.,
Gilbert,
R.
O.
(
1987)
Statistical
Methods
for
Environmental
Pollution
Monitoring,
Van
Nostrand
Reinhold
Company
New
York).
b
For
this
table,
values
below
0.375
were
set
equal
to
0.375,
which
is
¼
of
the
limit
of
detection.

5.3
Association
between
Interior
Dust
Lead
Hazards
and
Interior
LBP
Condition
Figure
5.8
presents
the
prevalence
of
interior
dust
lead
hazards
in
relation
to
the
condition
of
the
interior
LBP.
Table
5.8
presents
further
details
on
these
estimates.
Dust
lead
hazards
are
more
likely
to
exist
in
homes
with
deteriorated
LBP.
An
estimated
61
percent
(+
20%)
of
homes
with
significantly
deteriorated
LBP
have
lead
dust
hazards,
while
only
33
percent
(+
7%)
of
homes
with
LBP
in
good
condition
have
lead
dust
hazards.
Only
6
percent
(+
2%)
of
homes
with
no
interior
LBP
have
lead
dust
hazards.
Although
it
appears
from
the
data
that
the
presence
of
LBP,
especially
significantly
deteriorated
LBP,
contributes
to
higher
dust
lead
hazard,
there
are
additional
sources
of
lead
in
the
environment
to
account
for
dust
lead
in
homes
with
no
lead­
based
paint.

Table
5.8
also
allows
one
to
compare
the
relative
risks
(
95
percent
confidence
intervals
on
that
risk
are
not
shown
in
the
table)
of
interior
lead
dust
hazards
associated
with
different
paint
conditions.
The
presence
of
significantly
deteriorated
LBP
makes
a
house
1.8
(+
0.5)
times
as
likely
to
have
an
interior
lead
dust
hazard
compared
to
a
house
where
the
LBP
is
in
good
condition,
and
10.0
(+
1.9)
times
as
likely
as
a
house
without
LBP.
Even
a
house
with
LBP
in
good
condition
is
5.4
(+
0.8)
times
as
likely
to
have
interior
lead
dust
hazards
as
one
without
any
LBP.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
20
October
31,
2002
Figure
5.8
Association
Between
Dust
Lead
Hazards
and
Condition
of
Interior
Lead­
Based
Paint
Table
5.8
Association
Between
Dust
Lead
Hazards
and
Presence
and
Condition
of
Interior
Lead­
Based
Paint
No
LBP
on
Interior
or
Exterior
No
Interior
LBP
Interior
LBP
in
Good
Condition
Significantly
Deteriorated
Interior
LBP
Interior
Dust
Lead
Hazards
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
Number
(
000)
Percent
(%)
Estimatea
55,105
95%
62,752
94%
15,244
67%
2,389
39%

Lower
95%
CIb
51,893
90%
60,141
90%
12,633
56%
1,565
26%
None
Present
Upper
95%
CI
58,318
100%
65,363
98%
17,855
78%
3,213
53%

Estimate
2,686
5%
4,068
6%
7,508
33%
3,727
61%

Lower
95%
CI
1,372
2%
2,584
4%
6,024
26%
2,505
41%
Some
Present
Upper
95%
CI
4,001
7%
5,552
8%
8,992
40%
4,949
81%

Total
HUs
57,791
100%
66,820
100%
22,752
100%
6,116
100%

a
Estimate
is
either
the
number
of
permanently
occupied,
noninstitutional
housing
units
(
000)
in
which
children
are
permitted
to
live,
or
the
percentage
of
total
housing
units.
b
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
No
LBP
on
Interior
or
Exterior
No
Interior
LBP
Interior
LBP
in
Good
Condition
Significantly
Deteriorated
LBP
Number
of
Housing
Units
(
000)
Interior
Dust
Lead
Hazards
No
Interior
Dust
Lead
Hazards
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of
Lead
Final
Report,
Vol.
I
and
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Hazards
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5­
21
October
31,
2002
Tables
5.9
and
5.10
present
data
on
the
association
between
floor
and
sill
dust
lead
loadings
and
the
presence
of
interior
lead­
based
paint.
Both
tables
show
a
positive
relationship
between
the
presence
of
interior
lead­
based
paint
and
dust
lead
levels.
Housing
units
with
some
interior
LBP
are
twice
as
likely
to
have
floor
dust,
and
three
times
as
likely
to
have
window
sill
dust,
above
hazardous
levels
compared
to
housing
units
without
LBP.

Table
5.9
Association
Between
Floor
Dust
Lead
Loadings
and
Presence
of
Interior
Lead­
Based
Paint
Interior
Lead
Based
Paint
None
Present
Some
Present
Maximum
Floor
Dust
Lead
Loading
(
µ
g/
sq
ft)
a
Number
(
000)
Percent
(%)
b
Number
(
000)
Percent
(%)

LT
LODc
Number
HUsd
32,873
34%
5,496
6%
Lower
95%
CIe
29,475
31%
3,529
4%

Upper
95%
CI
36,270
38%
7,463
8%

GE
LOD
Number
HUs
33,824
35%
23,372
24%
Lower
95%
CI
30,086
31%
19,997
21%

Upper
95%
CI
37,561
39%
26,748
28%

GE
5
Number
HUs
12,242
13%
15,958
17%
Lower
95%
CI
9,835
10%
13,372
14%

Upper
95%
CI
14,650
15%
18,544
19%

GE
10
Number
HUs
6,003
6%
9,961
10%
Lower
95%
CI
4,238
4%
7,615
8%

Upper
95%
CI
7,768
8%
12,307
13%

GE
20
Number
HUs
2,493
3%
6,496
7%
Lower
95%
CI
1,606
2%
4,661
5%

Upper
95%
CI
3,381
4%
8,331
9%

GE
40
Number
HUs
1,666
2%
3,830
4%
Lower
95%
CI
993
1%
2,378
3%

Upper
95%
CI
2,338
3%
5,281
6%

GE
100
Number
HUs
1,122
1%
1,304
1%
Lower
95%
CI
419
0%
654
1%

Upper
95%
CI
1,825
2%
1,954
2%

Missing
Number
HUs
123
a
Missing
means
that
the
sill
or
trough
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
b
All
percentages
are
calculated
with
total
housing
units
as
the
denominator.
c
LT
equals
"
less
than."
GE
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
e
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
5­
22
October
31,
2002
Table
5.10
Association
Between
Window
Sill
Dust
Lead
Loadings
and
Presence
of
Interior
Lead­
Based
Paint
Interior
Lead
Based
Paint
None
Present
Some
Present
Maximum
Window
Sill
Dust
Lead
Loading
(
µ
g/
sq
ft)
a
Number
(
000)
Percent
(%)
b
Number
(
000)
Percent
(%)

LT
LODc
Number
HUsd
8,728
9%
874
1%
Lower
95%
CIe
6,544
7%
187
0%

Upper
95%
CI
10,912
12%
1,562
2%

GE
LOD
Number
HUs
54,454
57%
27,680
29%
Lower
95%
CI
51,195
54%
24,515
26%

Upper
95%
CI
57,713
60%
30,845
32%

GE
125
Number
HUs
6,553
7%
13,785
14%
Lower
95%
CI
5,043
5%
11,177
12%

Upper
95%
CI
8,063
8%
16,393
17%

GE
250
Number
HUs
3,434
4%
10,005
11%
Lower
95%
CI
2,193
2%
8,096
9%

Upper
95%
CI
4,675
5%
11,914
13%

GE
500
Number
HUs
1,498
2%
7,544
8%
Lower
95%
CI
651
1%
5,770
6%

Upper
95%
CI
2,346
3%
9,318
10%

No
sill
present
in
HUa
Number
HUs
2,043
0%
178
0%
Missing
Number
HUs
1,595
136
a
Missing
means
that
the
sill
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.,
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
b
All
percentages
are
calculated
with
total
housing
units
as
the
denominator.
c
LT
equals
"
less
than."
GE
equals
"
greater
than
or
equal
to."
LOD
equals
"
limit
of
detection."
d
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
e
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
1
October
31,
2002
6.
RESIDENTIAL
SOIL
LEAD
Chapter
6
presents
estimates
of
the
prevalence
of
soil
lead
by
lead
concentration,
and
the
association
between
soil
lead
concentration
and
exterior
lead­
based
paint
condition.
Relevant
estimates
are
compared
with
the
findings
of
the
1990
LBP
Survey.
The
prevalence
of
soil
lead
hazards
in
housing
is
presented
in
Chapter
3.
Since
soil
lead
hazards
include
lead
in
soil
in
children's
play
areas,
most
estimates
in
this
Chapter
are
based
on
the
subsample
of
375
homes
with
data
on
the
presence
or
absence
of
children's
play
areas
in
the
yards
and
on
the
extent
of
soil
lead
hazards
in
children's
play
areas.
A
few
tables
in
this
chapter
are
independent
of
the
presence
or
absence
of
lead­
contaminated
soil
in
children's
play
areas;
such
tables
are
therefore
based
on
the
full
sample
and
have
a
footnote
indicating
that
the
basis
is
the
full
sample.

6.1
Prevalence
of
Residential
Soil
Lead
Over
All
Sampled
Locations
A
composite
soil
sample
was
collected
at
each
of
five
sites
on
the
property
of
each
dwelling
unit:

1)
near
the
most
commonly
used
entrance,
2)
the
dripline
and
3)
the
mid­
yard
line
of
the
wall
with
the
main
entrance,
and
4)
the
dripline
and
5)
mid­
yard
line
of
a
second,
randomly­
selected
wall.
The
main
entrance
sample
was
a
composite
sample
of
two
cores
from
the
main
entrance
area.
The
dripline
and
mid­
yard
samples
on
each
wall
were
composite
samples
from
three
locations
along
the
length
of
the
sample
site.
In
addition,
soil
samples
were
collected
from
children's
play
areas
for
a
subsample
of
homes.
At
each
of
these
homes,
up
to
four
samples
were
collected
from
children's
play
equipment,
when
present;
otherwise,
one
sample
was
collected
from
an
area
of
the
yard
identified
as
being
where
children
play.
The
tables
in
this
section
and
in
Section
6.2
are
based
on
the
lead
concentration
data
from
all
of
these
soil
samples,
referenced
as
"
all
sampled
locations."
Section
6.3
then
presents
data
on
soil
lead
concentrations
in
children's
play
areas,
while
Section
6.4
presents
corresponding
data
for
the
"
rest
of
the
yard,"
i.
e.,
areas
not
identified
as
children's
play
areas.

Figure
6.1
and
Table
6.1
present
the
distribution
of
maximum
bare
soil
lead
concentrations.

Figure
6.1
presents
a
histogram
of
the
distribution,
while
Table
6.1
presents
the
number
and
percentage
of
HUs
by
selected
soil
lead
concentration
thresholds:
0,
20,
50,
200,
400,
1,200,
1,600,
2,000,
and
5,000
ppm.

Figure
6.1
and
Table
6.1
include
bare
soil
from
all
sampled
locations,
both
play
areas
and
all
other
locations.

An
estimated
58
percent
(
±
8%)
of
homes
have
soil
lead
levels
above
the
limit
of
detection.
47
An
estimated
10
47
The
sample
limit
of
detection
for
this
study
was
determined
to
be
20
ppm
by
testing
four
distinct
soil
types
from
among
the
study
samples
in
accordance
with
EPA
SW
840
Method
3050
procedures.
National
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of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
2
October
31,
2002
percent
(
±
4%)
48
of
homes
have
soil
lead
levels
above
400
ppm,
and
7%
(
±
4%)
have
soil
lead
levels
above
1,200
ppm.
Only
3
percent
of
homes
were
found
to
have
soil
lead
above
2,000
ppm.
The
maximum
soil
values
for
each
HU
have
been
used
in
Table
6.1.
The
effect
of
using
the
average
soil
lead
for
each
HU
would
drive
the
distribution
towards
the
lower
thresholds,
i.
e.
more
homes
have
lower
average
soil
lead
concentrations.

Care
is
to
be
exercised
in
comparing
the
tables
in
this
Chapter
with
Table
3.3,
which
tabulate
the
prevalence
of
soil
lead
hazards.
The
tables
in
this
chapter
present
the
distribution
of
residential
soil
lead
concentrations
at
selected
locations,
while
soil
lead
hazards
are
defined
in
terms
of
soil
lead
concentrations
in
two
types
of
locations.
Specifically,
a
housing
unit
is
defined
to
have
a
soil
lead
hazard
if
soil
lead
concentrations
exceed
400
ppm
in
play
areas
or
exceed
1,200
ppm
in
the
rest
of
the
yard.
Thus,
the
tables
in
this
section
do
not
directly
compare
with
Table
3.3.

Figure
6.1
Distribution
of
Maximum
Bare
Soil
Lead
Concentrations
48
All
confidence
intervals
are
at
the
95
percent
level
for
the
estimated
number
or
percentage.
0
10
20
30
40
50
<
20
20­
50
50­
200
200­
400
400­
1200
1200­
1600
1600­
2000
2000­
5000
>
5000
Lead
Concentrations
(
ppm)
HUs
(%)
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
3
October
31,
2002
Table
6.1
Distribution
of
Maximum
Bare
Soil
Sample
Lead
Concentrations
(
All
Sampled
Locations)

Bare
Soil
Lead
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
GEd0
ppm
77,888
72,054
83,722
81%
75%
88%
GE
20
ppm
55,114
47,348
62,881
58%
50%
66%
GE
50
ppm
40,023
31,365
48,680
42%
33%
51%
GE
200
ppm
15,299
11,626
18,971
16%
12%
20%
GE
400
ppm
9,996
6,398
13,594
10%
7%
14%
GE
1,200
ppm
6,271
2,733
9,809
7%
3%
10%
GE
1,600
ppm
3,900
1,670
6,131
4%
2%
6%
GE
2,000
ppm
3,124
827
5,420
3%
1%
6%
GE
5,000
ppm
1,580
0
3,309
2%
0%
4%
No
Bare
Soil
15,413
9,789
21,037
16%
10%
22%
No
Soil
2,242
330
4,154
2%
0%
4%
Missinge
145
0
527
0%
0%
1%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
d
GE
equals
"
greater
than
or
equal
to."
e
"
Missing"
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
"
No
soil"
means
that
there
was
no
soil
on
the
property
to
sample.

Table
6.2
presents
the
number
and
percentage
of
housing
units
by
construction
year
for
selected
soil
lead
concentration
thresholds
for
bare
soil
only,
again
for
all
sampling
locations.
As
seen
above
for
all
soil,
as
the
soil
lead
threshold
increases,
the
number
of
newer
homes
meeting
the
criteria
for
bare
soil
decreases
faster
than
the
older
homes.
In
fact,
practically
no
newer
homes
(
1960­
1998)
have
lead
in
bare
soil
above
1,200
ppm,
and
less
than
4
percent
have
soil
lead
above
400
ppm.
49
Thus,
the
data
suggest
that
older
homes
have
higher
bare
soil
lead
levels
than
new
homes.
Since
the
amount
of
lead
added
to
commercial
residential
paint
declined
from
1940
to
1980,
these
observations
are
not
unreasonable,
and
have
been
reported
by
others.
50
49
Even
fewer
homes
will
have
greater
than
9
square
feet
of
bare
soil
above
400
ppm
or
2,000
ppm
(
soil
lead
hazard
as
specified
in
the
Lead
Safe
Housing
Rule).

50
Francek,
M.
(
1992.)
Soil
lead
levels
in
a
small
town
environment:
A
case
study
from
Mt.
Pleasant,
Michigan.
Environmental
Pollution
76.
pp.
251­
257.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
4
October
31,
2002
Table
6.2
Distribution
of
Maximum
Bare
Soil
Sample
Lead
Concentration
by
Construction
Year
(
All
Sampled
Locations)

Bare
Soil
Lead
Concentration
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Before
1940
1940
­
1959
1960
 
1977
1978
­
1998
Before
1940
1940
­
1959
1960
­
1977
1978
­
1998
GEc
0
ppm
12,015
16,843
23,185
25,845
69%
82%
83%
87%
GE
20
ppm
12,015
15,404
17,345
10,350
69%
75%
62%
35%
GE
50
ppm
11,193
12,789
10,437
5,603
64%
62%
37%
19%
GE
200
ppm
7,243
6,073
1,793
190
41%
30%
6%
1%
GE
400
ppm
5,148
3,736
1,111
0
30%
18%
4%
0%
GE
1,200
ppm
3,386
2,886
0
0
19%
14%
0%
0%
GE
1,600
ppm
2,006
1,894
0
0
12%
9%
0%
0%
GE
2,000
ppm
1,320
1,804
0
0
8%
9%
0%
0%
GE
5,000
ppm
1,106
475
0
0
6%
2%
0%
0%
Missingd
145
0
0
0
1%
0%
0%
0%
No
Bare
Soil
4,313
2,762
4,613
3,724
25%
13%
17%
13%
No
Soil
1,003
939
95
205
6%
5%
0%
1%
Total
17,476
20,544
27,893
29,774
100%
100%
100%
100%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
of
that
age
as
the
common
denominator.
c
GE
equals
"
greater
than
or
equal
to."
d
Missing
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
usually
due
to
inaccessibility
or
respondent
refusal).
"
No
soil"
means
that
there
was
no
soil
on
the
property
to
sample.

Figure
6.2
presents
a
series
of
boxplots51
showing
the
distribution
of
soil
lead
concentrations
at
each
of
the
seven
sample
sites.
The
last
two
boxplots
represent
only
the
data
collected
during
the
supplemental
data
collection
from
play
areas.
As
with
paint
lead
and
dust
lead
loadings,
soil
lead
concentrations
are
extremely
skewed
with
over
three­
fourths
of
the
samples
under
200
ppm,
but
some
samples
are
well
above
1,000
ppm.

Table
6.3
presents
selected
parameters
of
the
distributions
of
soil
lead
concentrations
by
sample
sites,
corresponding
to
the
first
five
boxplots
in
Figure
6.2.
Table
6.3
also
presents
geometric
means
and
standard
deviations.
As
with
the
distributions
of
paint
lead
loadings
and
dust
lead
loadings,
the
distribution
of
soil
lead
concentrations
is
right­
skewed.
Thus,
a
normal
distribution
would
not
be
a
suitable
model
for
the
distribution.
A
lognormal
distribution
would
be
a
more
suitable
distribution.
Appendix
C
includes
a
discussion
of
modeling
these
data.

51
Soil
lead
concentration
data
is
presented
in
box
plot
form.
Each
box
plot
shows
a
univariate
data
distribution,
for
example,
the
soil
samples
collected
from
a
specific
location
(
e.
g.,
main
entry).
The
box
in
the
box
plot
represents
the
middle
50
percent
of
the
data;
the
bottom
of
the
box
gives
the
25th
percentile;
the
top
of
the
box
gives
the
75th
percentile;
and
the
horizontal
line
inside
the
box
gives
the
median
or
50th
percentile.
The
vertical
lines
extending
from
the
top
and
bottom
of
the
box
reach
to
the
largest
and
smallest
observations,
respectively,
except
for
outliers.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
5
October
31,
2002
Figure
6.2
Box
Plots
for
Lead
in
Soil
Samples
by
Sample
Site
a
The
box
in
the
box
plot
represents
the
middle
50
percent
of
the
data;
the
bottom
of
the
box
gives
the
25th
percentile;
the
top
of
the
box
gives
the
75th
percentile,
and
the
horizontal
line
inside
the
box
gives
the
median
or
50th
percentile.
The
vertical
lines
extending
from
the
top
and
bottom
of
the
box
reach
to
the
largest
and
smallest
observations,
respectively,
except
for
outliers.

b
"
Wall
1"
refers
to
the
main
entrance
wall
and
"
Wall
2"
refers
to
the
second,
randomly­
selected
wall.
1
10
100
1000
10000
100000
Main
Entry
Wall
1
Dripline
Wall
2
Dripline
Wall
1
Midyard
Wall
2
Midyard
Play
area
Under
Play
Equipment
Soil
Sample
Location
Soil
Lead
Concentration
(
ppm)
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
6
October
31,
2002
Table
6.3
Estimated
Empirical
Distribution
Parameters
of
Soil
Lead
Concentrations
by
Sample
Site
Main
Entry
Wall
1
Dripline
Wall
2
Dripline
Wall
1
Midyard
Wall
2
Midyard
ppm
ppm
ppm
ppm
ppm
Arithmetic
Mean
234.8
242.9
404.1
87.3
123.4
Arithmetic
Standard
Deviation
1,094.4
817.6
1,612.7
194.7
360.4
Geometric
Mean
43.3
44.5
49.0
28.1
29.9
Geometric
Standard
Deviationa
5.6
5.8
6.8
4.3
4.9
25th
Percentile
12.1
11.4
10.8
7.8
8.5
Median
40.2
38.8
40.3
27.0
29.1
75th
Percentile
133.4
130.7
165.4
76.3
74.2
90th
Percentile
433.5
553.5
712.5
209.0
277.0
95th
Percentile
1,005.8
1,110.8
1,444.5
411.3
538.8
Number
of
Samples
707
704
704
723
728
a
The
geometric
standard
deviation
is
computed
as
exp(
s),
where
s
is
the
arithmetic
standard
deviation
of
the
natural
logarithms
of
the
concentrations
(
see,
e.
g.,
Gilbert,
R.
O.
(
1987)
Statistical
Methods
for
Environmental
Pollution
Monitoring,
Van
Nostrand
Reinhold
Company
New
York).
For
the
calculations
of
the
geometric
mean
and
standard
deviation,
zero
and
negative
values
were
set
to
5.

6.2
Association
between
Bare
Soil
Lead
and
Exterior
Paint
Condition
Table
6.4
and
Figure
6.3
show
the
association
between
bare
soil
lead
concentration
and
the
condition
of
the
exterior
LBP.
Higher
bare
soil
lead
concentrations
occur
for
homes
with
deteriorated
LBP.

An
estimated
56
percent
(
±
8%)
of
homes
with
intact
or
minimally­
deteriorated
LBP
have
bare
soil
lead
above
20
ppm,
while
73
percent
(
±
19%)
of
homes
with
significantly
deteriorated
LBP
have
bare
soil
levels
above
20
ppm.
Only
4
and
2
percent
of
homes
free
of
significantly
deteriorated
LBP
have
bare
soil
lead
levels
above
1,200
and
2,000
ppm,
respectively,
while
24
and
13
percent
of
homes
with
significantly
deteriorated
LBP
have
bare
soil
lead
levels
above
1,200
and
2,000
ppm,
respectively.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
7
October
31,
2002
Table
6.4
Association
Between
Bare
Soil
Lead
Concentration
and
Presence
of
Significantly
Deteriorated
Exterior
LBP
(
All
Sampled
Locations)

Bare
Soil
Lead
Housing
Units
without
Any
Exterior
LBPa,
b
Housing
Units
without
Significantly
Deteriorated
Exterior
LBPa,
b
Housing
Units
with
Significantly
Deteriorated
Exterior
LBPa,
b
Percent
Lower
95%
CIc
Upper
95%
CI
Percent
Lower
95%
CI
Upper
95%
CI
Percent
Lower
95%
CI
Upper
95%
CI
GEd0
ppm
83%
78%
88%
83%
77%
88%
73%
55%
92%
GE
20
ppm
49%
41%
56%
56%
48%
63%
73%
54%
92%
GE
50
ppm
28%
20%
36%
38%
30%
47%
67%
51%
83%
GE
200
ppm
5%
1%
9%
13%
9%
17%
39%
19%
58%
GE
400
ppm
3%
0%
5%
8%
5%
11%
30%
11%
49%
GE
1,200
ppm
1%
0%
3%
4%
2%
7%
24%
7%
41%
GE
1,600
ppm
1%
0%
3%
2%
1%
4%
17%
4%
30%
GE
2,000
ppm
1%
0%
2%
2%
0%
4%
13%
2%
24%
GE
5,000
ppm
0%
0%
0%
1%
0%
2%
8%
0%
17%
Missinge
0%
0%
0%
30%
0%
0%
1%
0%
5%
No
Bare
Soil
14%
10%
19%
15%
11%
20%
22%
3%
41%
No
Soil
3%
0%
6%
2%
0%
4%
4%
0%
9%
Total
100%
100%
100%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
The
denominators
for
the
percentages
are
66,032,000
HUs
without
any
exterior
LBP,
84,215,000
HUs
without
significantly
deteriorated
exterior
LBP,
and
11,473,000
HUs
with
significantly
deteriorated
exterior
LBP.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
d
GE
equals
"
greater
than
or
equal
to."
e
Missing
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
usually
due
to
inaccessibility
or
respondent
refusal).
"
No
soil"
means
that
there
was
no
soil
on
the
property
to
sample.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
8
October
31,
2002
Figure
6.3
Association
Between
Lead
in
Bare
Soil
and
Deteriorated
Exterior
Lead­
Based
Paint
6.3
Prevalence
of
Bare
Soil
Lead
in
Children's
Play
Areas
Table
6.5
presents
the
number
and
percentage
of
housing
units
with
bare
soil
lead
in
children's
play
areas
above
selected
concentration
thresholds:
0,
20,
50,
200,
400,
1,200,
1,600,
2,000,
and
5,000
ppm.

Figure
6.4
presents
the
point
estimates
as
a
histogram.
An
estimated
51
percent
(
±
6%)
of
homes
have
bare
soil
lead
levels
in
play
areas
above
the
limit
of
detection.
52
An
estimated
five
percent
(
±
3%)
of
homes
with
play
areas
have
soil
lead
levels
above
400
ppm,
while
an
estimated
two
percent
(
±
2%)
of
homes
have
play
area
soil
lead
levels
above
2,000
ppm.

Where
more
than
one
soil
sample
was
collected
from
children's
play
areas
at
a
home,
the
maximum
soil
value
for
housing
unit
has
been
used
in
Table
6.5.
The
effect
of
using
the
average
soil
lead
for
each
housing
unit
would
drive
the
distribution
towards
the
lower
thresholds,
i.
e.
more
homes
would
have
lower
soil
lead
concentrations.

52
The
sample
limit
of
detection
for
this
study
was
determined
to
be
20
ppm
by
testing
four
distinct
soil
types
from
among
the
study
samples
in
accordance
with
EPA
Method
3050
procedures.
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%

GE
0
GE
20
GE
50
GE
200
GE
400
GE
1,200
GE
1,600
GE
2,000
GE
5,000
Bare
Soil
Lead
Concentration
(
ppm)
Percent
of
Housing
Units
Housing
Units
without
Any
Exterior
LBP
Housing
Units
without
Significantly
Deteriorated
Exterior
LBP
Housing
Units
with
Significantly
Deteriorated
Exterior
LBP
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
9
October
31,
2002
Figure
6.4
Distribution
of
Maximum
Bare
Play
Area
Soil
Lead
Concentration
Table
6.5
Distribution
of
Maximum
Soil
Lead
Concentrations
in
Children's
Play
Areas
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Bare
Play
Area
Soil
Lead
HUs
in
Sample
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
GEd0
ppm
76,404
69,826
82,982
80%
73%
87%
294
GE
20
ppm
49,019
42,946
55,092
51%
45%
58%
209
GE
50
ppm
28,878
25,828
31,929
30%
27%
33%
127
GE
200
ppm
10,849
7,899
13,800
11%
8%
14%
101
GE
400
ppm
4,856
2,096
7,616
5%
2%
8%
84
GE
1,200
ppm
2,493
458
4,529
3%
1%
5%
82
GE
1,600
ppm
2,078
92
4,063
2%
0%
4%
80
GE
2,000
ppm
1,777
0
3,871
2%
0%
4%
77
GE
5,000
ppm
380
0
1,231
0%
0%
1%
1
No
play
area
12,368
6,659
18,077
13%
7%
19%
53
Missinge
6,916
1,862
11,969
7%
2%
13%
23
Total
95,688
100%
375
a
"
Housing
units"
are
permanently
occupied,
noninstitutional
residential
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
d
GE
equals
"
greater
than
or
equal
to."
e
Missing
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
usually
due
to
inaccessibility
or
respondent
refusal).
"
No
soil"
means
that
there
was
no
soil
on
the
property
to
sample.
0
10
20
30
40
50
<
20
20­
50
50­
200
200­
400
400­
1200
1200­
1600
1600­
2000
2000­
5000
>
5000
Lead
Concentrations
(
ppm)
HUs
(%)
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
10
October
31,
2002
Table
6.6
presents
the
number
and
percentage
of
housing
units
with
bare
soil
lead
concentration
in
children's
play
areas
by
selected
thresholds,
by
housing
unit
construction
year.
In
general,
as
the
soil
lead
threshold
increases,
the
number
of
homes
meeting
the
criteria
decreases
as
the
housing
unit
age
increases.
In
fact,
nearly
all
newer
homes
(
1960­
1998)
have
bare
play
area
soil
lead
below
400
ppm.
Thus,
the
data
suggest
that
older
homes
have
higher
bare
play
area
soil
lead
concentrations
than
new
homes.
Since
the
amount
of
lead
added
to
commercial
residential
paint
declined
from
1940
to
1980,
these
observations
are
not
unreasonable,
and
have
been
reported
by
others.
53
Table
6.6
Distribution
of
Maximum
Soil
Lead
Concentrations
in
Children's
Play
Areas,
by
Construction
Year
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Bare
Soil
Lead
Concentration
Before
1940
1940
 
1959
1960
 
1977
1978
 
1998
Before
1940
1940
 
1959
1960
­
1977
1978
 
1998
GEc0
ppm
14,641
15,953
22,536
23,275
84%
78%
81%
78%
GE
20
ppm
14,552
13,074
13,238
8,155
83%
64%
48%
27%
GE
50
ppm
12,562
8,920
4,733
2,664
72%
43%
17%
9%
GE
200
ppm
6,508
2,804
320
1,217
37%
14%
1%
4%
GE
400
ppm
3,325
1,469
62
0
19%
7%
0%
0%
GE
1,200
ppm
1,498
995
0
0
9%
5%
0%
0%
GE
1,600
ppm
1,082
995
0
0
6%
5%
0%
0%
GE
2,000
ppm
872
905
0
0
5%
4%
0%
0%
GE
5,000
ppm
380
0
0
0
2%
0%
0%
0%
No
Play
Area
613
102
3,410
2,790
13%
22%
7%
13%
Missingd
2,222
4,489
1,947
3,710
4%
1%
12%
9%
Total
17,476
20,544
27,893
29,774
100%
100%
100%
100%

a
"
Housing
units"
are
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
of
that
age
as
the
common
denominator.
c
GE
equals
"
greater
than
or
equal
to."
d
Missing
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
usually
due
to
inaccessibility
or
respondent
refusal).
"
No
bare
soil"
means
that
there
was
no
bare
soil
in
children's
play
areas
on
the
property
to
sample.

Table
6.7
shows
the
association
between
bare
play
area
soil
lead
concentration
and
the
condition
of
the
exterior
LBP.
Higher
bare
soil
lead
concentrations
occur
in
play
areas
for
homes
with
significantly
deteriorated
LBP.
An
estimated
46
percent
(
±
7%)
of
homes
with
intact
or
minimally­
deteriorated
LBP
have
bare
play
area
soil
lead
above
20
ppm,
while
89
percent
(
±
11%)
of
homes
with
significantly
deteriorated
LBP
have
bare
soil
levels
above
20
ppm.
Only
three
percent
(
±
3%)
of
homes
with
intact
or
minimally­
deteriorated
LBP
have
bare
play
area
soil
lead
levels
above
400
ppm,
while
18
percent
(
±
12%)
of
homes
with
significantly
deteriorated
LBP
have
bare
soil
lead
levels
above
400
ppm.

53
Francek,
M.
(
1992.)
Soil
lead
levels
in
a
small
town
environment:
A
case
study
from
Mt.
Pleasant,
Michigan.
Environmental
Pollution
76.
pp.
251­
257.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
11
October
31,
2002
Table
6.7
Association
Between
Bare
Soil
Lead
Concentration
and
Presence
of
Significantly
Deteriorated
Exterior
LBP,
in
Children's
Play
Areas
Bare
Play
Area
Soil
Lead
Housing
Units
without
Significantly
Deteriorated
Exterior
LBP
(%)
a,
b
Housing
Units
with
Significantly
Deteriorated
Exterior
LBP
(%)
a,
b
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
GEd0
ppm
79%
71%
86%
90%
79%
100%
GE
20
ppm
46%
39%
53%
89%
77%
100%
GE
50
ppm
24%
20%
29%
73%
55%
91%
GE
200
ppm
8%
4%
12%
35%
17%
53%
GE
400
ppm
3%
1%
6%
18%
6%
30%
GE
1,200
ppm
1%
0%
3%
13%
2%
24%
GE
1,600
ppm
1%
0%
3%
11%
0%
23%
GE
2,000
ppm
1%
0%
2%
10%
0%
23%
GE
5,000
ppm
0%
0%
0%
3%
0%
11%
No
Play
Areas
14%
7%
20%
7%
0%
17%
Missinge
8%
2%
14%
3%
0%
7%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
Percentages
are
calculated
with
the
number
of
HUs
with
and
without
significantly
deteriorated
LBP,
11,472
and
84,216,
respectively,
as
the
denominators.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
d
GE
equals
"
greater
than
or
equal
to."
e
Missing
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
usually
due
to
inaccessibility
or
respondent
refusal).
"
No
soil"
means
that
there
was
no
soil
on
the
property
to
sample.

6.4
Prevalence
of
Soil
Lead
in
the
Rest
of
the
Yard
Table
6.8
presents
the
number
and
percentage
of
housing
units
with
soil
lead
in
the
rest
of
the
yard
­­
i.
e.,
areas
not
identified
as
children's
play
areas
­­
above
selected
concentration
thresholds:
0,
50,
200,

400,
1,200,
1,600,
2,000,
and
5,000
ppm.
An
estimated
75
percent
(
±
6%)
of
homes
have
bare
soil
lead
levels
in
the
rest
of
the
yard
above
the
limit
of
detection.
54
An
estimated
10
percent
(
±
4%)
of
homes
have
soil
lead
levels
above
1,200
ppm
in
the
rest
of
the
yard,
while
an
estimated
6
percent
(
±
2%)
of
homes
have
soil
lead
levels
above
2,000
ppm.

54
The
sample
limit
of
detection
for
this
study
was
determined
to
be
20
ppm
by
testing
four
distinct
soil
types
from
among
the
study
samples
in
accordance
with
EPA
Method
3050
procedures.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
12
October
31,
2002
Table
6.8
Distribution
of
Maximum
Soil
Lead
Concentrations
in
the
Rest
of
the
Yard
Soil
Lead
Concentration
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
HUs
in
Sample
GEd
0
ppm
90,348
87,218
93,479
94%
91%
98%
323
GE
20
ppm
71,537
65,843
77,230
75%
69%
81%
258
GE
50
ppm
54,250
48,525
59,976
57%
51%
63%
162
GE
200
ppm
27,353
25,438
29,267
29%
27%
31%
116
GE
400
ppm
19,709
16,109
23,310
21%
17%
24%
70
GE
1,200
ppm
9,939
6,435
13,444
10%
7%
14%
53
GE
1,600
ppm
6,220
4,034
8,407
7%
4%
9%
49
GE
2,000
ppm
5,905
3,727
8,083
6%
4%
8%
38
GE
5,000
ppm
2,987
1,548
4,427
3%
2%
5%
17
No
Soil/
No
Bare
Soile
2,310
366
4,254
2%
0%
4%
9
Missinge
3,029
693
5,365
3%
1%
6%
12
Total
95,688
100%
375
a
"
Housing
units"
are
permanently
occupied,
noninstitutional
residential
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
d
GE
equals
"
greater
than
or
equal
to."
e
Missing
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
usually
due
to
inaccessibility
or
respondent
refusal).
"
No
soil"
means
that
there
was
no
soil
in
the
rest
of
the
yard
to
sample.
"
No
bare
soil"
means
there
was
no
bare
soil
in
the
rest
of
the
yard.

Table
6.9
presents
the
number
and
percentage
of
housing
units
with
soil
lead
concentration
in
the
rest
of
the
yard
by
selected
thresholds,
and
by
housing
unit
construction
year.
In
general,
as
the
soil
lead
threshold
increases,
the
number
of
homes
meeting
the
criteria
decreases
as
the
housing
unit
age
increases.
In
fact,
nearly
all
(
91%)
homes
built
between
1960
and
1977
have
bare
soil
lead
concentrations
below
400
ppm
in
the
rest
of
the
yard.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
13
October
31,
2002
Table
6.9
Distribution
of
Maximum
Soil
Lead
Concentrations
in
the
Rest
of
the
Yard,
by
Construction
Year
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Bare
Soil
Lead
Concentration
Before
1940
1940
­
1959
1960
­
1977
1978
­
1998
Before
1940
1940
 
1959
1960
­
1977
1978
 
1998
GEc0
ppm
15,858
19,372
26,950
28,168
91%
94%
97%
95%
GE
20
ppm
15,858
18,947
24,151
12,581
91%
92%
87%
42%
GE
50
ppm
15,350
17,492
13,509
7,900
88%
85%
48%
27%
GE
200
ppm
13,051
9,524
4,430
348
75%
46%
16%
1%
GE
400
ppm
11,255
5,960
2,410
84
64%
29%
9%
0%
GE
1,200
ppm
6,326
2,926
686
0
36%
14%
3%
0%
GE
1,600
ppm
4,245
1,289
686
0
24%
6%
3%
0%
GE
2,000
ppm
3,929
1,289
686
0
23%
6%
3%
0%
GE
5,000
ppm
1,891
865
231
0
11%
4%
1%
0%
No
Soil/
No
Bare
Soile
1,211
939
160
0
7%
5%
1%
0%
Missingd
407
233
783
1,606
2%
1%
3%
5%
Total
17,476
20,544
27,893
29,774
100%
100%
100%
100%

a
"
Housing
units"
are
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
of
that
age
as
the
common
denominator.
c
GE
equals
"
greater
than
or
equal
to."
d
Missing
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
usually
due
to
inaccessibility
or
respondent
refusal).
e
"
No
soil"
means
that
there
was
no
soil
in
the
rest
of
the
yard
to
sample.
"
No
bare
soil"
means
there
was
no
bare
soil
in
the
rest
of
the
yard.

6.5
Comparison
of
Prevalence
of
Soil
Lead
to
the
1990
LBP
Survey
Table
6.10
compares
the
prevalence
of
soil
lead
found
in
the
NSLAH
with
the
prevalence
of
soil
lead
found
in
the
1990
LBP
Survey.
The
estimate
of
homes
reported
for
the
NSLAH
have
been
limited
to
those
with
500
ppm55
soil
lead
or
greater
and
to
homes
built
before
1980
for
comparability
to
the
1990
LBP
Survey
protocols
and
findings
(
see
Appendix
B
for
a
comparison
of
the
protocols
for
the
two
studies).

Statistical
comparison
shows
no
significant
difference
in
the
prevalence
of
soil
above
or
below
500
ppm
in
the
two
studies.

55
At
the
time
the
1990
LBP
survey
was
conducted,
500
ppm
was
the
guideline
in
EPA's
Interim
Guidance
on
Establishing
Soil
Lead
Cleanup
Levels
at
Superfand
Sites,
September
7,
1989
(
OSWER
Directive
#
9355­
4­
02).
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
6­
14
October
31,
2002
Table
6.10
Comparison
of
the
Prevalence
of
Lead­
Contaminated
Bare
Soil
in
the
NSLAH
and
the
1990
LBP
Survey
1990
LBP
Survey
(
pre­
1980
HUs)
Current
NSLAH
(
pre­
1980
HUs)
Number
(
000)
Percent
(%)
Number
(
000)
Percent
and
(
CI)
a
(%)
HUs
with
Bare
Soil
Lead
Above
500
ppm
15,699
20%
15,909
23%
(
19­
27%)
HUs
with
Bare
Soil
Lead
Equal
to
or
Below
500
ppm
61,478
80%
50,290
73%
(
70­
77%)

No
Bare
Soil
­­
­­
2,557
4%

Total
77,177
100%
68,756
100%

a
CI
=
95%
confidence
interval
for
the
estimated
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
1
7.
QUALITY
OF
THE
NATIONAL
SURVEY
DATA
Chapter
7
examines
the
quality
of
the
data
and
the
resulting
quality
of
projected
national
estimates.
The
greatest
source
of
error
(
in
the
statistical
sense)
in
the
NSLAH
estimates
is
sampling
error
 

as
discussed
in
Volume
II,
Chapter
2.
This
chapter
addresses
two
additional
important
potential
sources
of
error
 
nonresponse
bias
and
measurement
bias
 
and
discusses
their
effects
on
the
national
estimates
of
the
prevalence
of
lead­
based
paint
(
LBP),
lead
in
dust,
and
lead
in
soil.
56
The
chapter
concludes
with
a
summary
of
the
data
collection
quality
assurance
activities,

including
results
of
telephone
verification,
field
team
audits,
field
dust
and
soil
quality
control
samples,

laboratory
performance
on
dust
and
soil
quality
control
samples,
and
paint
testing
quality
control.

7.1
Statistical
Concepts
and
Terminology
There
are
two
broad
types
of
error
in
survey
estimates:
sampling
error
and
nonsampling
error:


Sampling
error:
Sampling
error
arises
from
surveying
a
random
sample
rather
than
a
complete
census
of
all
housing
units
(
HUs).
It
is
a
function
of
the
sample
size
and
sample
design.
Different
samples
of
the
same
size
drawn
using
the
same
sample
design
will
yield
varying
estimates
of
the
population
parameters.
This
variation
about
the
true
population
parameter
is
the
sampling
error.


Nonsampling
error:
Nonsampling
errors
arise
from
a
number
of
sources,
including
differential
response
rates
from
different
demographic
groups,
types
of
HUs,
and
geographical
areas;
unknown
differences
between
the
respondents
and
nonrespondents;
differences
between
the
sample
frame
and
the
target
population;
some
types
of
processing
and
data
reduction
techniques;
and
classification
bias
due
to
measurement
error
inherent
in
XRF
and
laboratory
instrumentation
and
variation
in
a
measured
parameter
across
a
surface
and
among
rooms.

Throughout
the
report,
the
term
weight
has
been
used
in
conjunction
with
the
sampled
HUs,

rooms,
and
surfaces.
It
is
important
that
these
terms
be
understood.

56
Another
source
of
error
in
the
survey
is
response
bias,
i.
e.,
how
correct
was
the
information
provided
by
the
respondents?
Significant
information
obtained
from
respondents
included
year
of
construction
(
HU
age)
and
age
of
children.
These
data
were
not
verified
by
other
means
and
are
thus
associated
with
an
unknown
amount
of
error.
However,
the
overall
distribution
of
HU
age
and
age
of
children
reported
by
survey
respondents
were
consistent
with
study
expectations
(
see
Volume
II,
Chapter
2),
indicating
no
systematic
bias
in
these
responses.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
2

Housing
Unit
(
HU)
weight:
The
HU
weight
is
the
number
of
HUs
in
the
target
population
that
a
single
HU
in
the
survey
represents.
The
weight
is
calculated
by
taking
the
inverse
of
the
probability
of
selection
for
that
unit.
Thus,
if
the
probability
of
selection
is
0.01,
the
sample
weight
is
100.
With
multi­
stage
samples,
the
overall
probability
of
selection
is
the
product
of
the
conditional
probabilities
of
selection
at
each
stage.
HU
weights
for
this
survey
reflect
nonresponse
adjustments
and
post­
stratification
to
the
1997
American
Housing
Survey
(
AHS)
housing
unit
totals
by
Census
region,
HU
age
category,
and
presence
of
children
under
age
18.


Room
weight:
The
room
weight
is
the
number
of
rooms
in
the
target
population
that
a
single
room
in
the
survey
represents.
Room
weights
were
determined
by
dividing
the
post­
stratified
HU
weights
by
the
probability
of
room
selection
based
on
the
inventory
of
all
rooms
in
each
HU.
A
nonresponse
adjustment
was
then
made
to
account
for
noncompleted
rooms.
A
room
was
only
considered
to
be
complete
if
some
environmental
samples
and
data
were
collected
in
the
room.


Component
weight:
The
component
weight
is
the
number
of
components
in
the
target
population
that
a
single
component
tested
in
the
survey
represents.
For
most
lead
samples,
the
component
weight
equaled
the
nonresponse­
adjusted
room
weight.
There
were
two
exceptions:
1)
XRF
measurements
on
windows
and
doors,
and
2)
window
dust
samples.
For
these
components,
a
sample
of
one
door
or
window
per
room
was
selected.
To
complete
component
weights
for
these
components,
the
nonresponse­
adjusted
room
weights
were
divided
by
the
component
probability
of
selection,
i.
e.,
the
inverse
of
the
total
number
of
doors
or
windows
in
the
room.

7.2
Potential
for
Nonresponse
Bias
The
objective
of
the
nonresponse
analysis
was
to
estimate
the
potential
impact
of
survey
nonresponse
on
the
estimated
prevalence
of
LBP
in
housing.
To
accomplish
this,
three
analyses
were
conducted.
First,
the
weighted
distribution
of
the
NSLAH
sample
was
compared
and
found
to
be
comparable
with
the
AHS
and
CPS
(
this
analysis
was
presented
in
Chapter
2).
Second,
an
analysis
of
completion
rates
was
performed
to
look
for
correlates
with
nonresponse.
Third,
the
survey
estimates
for
the
"
hard­
to­
recruit"
and
HUs
that
initially
refused
(
proxies
for
the
nonrespondents)
were
compared
with
estimates
from
HUs
that
were
relatively
easy
to
recruit
and
had
no
history
of
refusal.

7.2.1
Analysis
of
Completion
and
Response
Rates
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
3
An
analysis
of
completion
rates
was
conducted
for
the
entire
sample
of
1,984
fielded
HUs.

The
analysis
looked
at
the
relationship
between
completion
rates
and
factors
such
as
age
of
housing,
race,

ethnicity,
geographic
location,
income,
tenure,
and
presence
of
multi­
family
housing.
Given
that
these
data
were
generally
not
available
at
the
individual
HU
level
for
the
noncompletes,
data
for
the
block
group
to
which
the
HU
belonged
was
used
for
the
entire
sample,
with
the
exception
of
HU
age.
The
housing
unit
age
reported
by
respondents
was
used
when
available,
which
was
the
case
for
approximately
one­
half
of
the
HUs.
The
source
of
the
block
group
data
was
the
1990
Census.
Completion
rates
were
also
compared
for
HUs
receiving
an
advance
letter
addressed
to
"
Current
Resident"
and
HUs
receiving
a
letter
addressed
to
a
household
member.

The
completion
rates
for
the
analysis
were
calculated
as
the
weighted
proportion
of
the
HUs
sampled
that
completed
both
screener
and
data
collection,
or
else
were
found
to
be
ineligible.
Ineligibles
were
considered
to
be
screener
completes
in
the
sense
that
their
eligibility
status
was
determined
during
the
screener.
For
a
large
proportion
of
the
sample
(
39%),
eligibility
could
not
be
determined,
usually
because
contact
could
not
be
made.
Most
nonresponse
occurred
at
the
screener
stage
and
resulted
in
unknown
eligibility
status.
Of
the
1,984
HUs
sampled,
831
completed
both
the
screener
and
data
collection
and
229
were
found
to
be
ineligible.
Of
the
remaining
924
that
did
not
complete
the
data
collection,
149
were
eligible
and
another
775
were
of
unknown
eligibility.
Thus,
there
were
1,060
completes
and
924
noncompletes
overall.
The
overall
unweighted
completion
rate
for
the
survey
was
53.4
percent;
the
overall
weighted
completion
rate
was
53.1
percent.

Formulas
for
unweighted
screener
and
data
collection
completion
rates
are
given
below,
along
with
the
eligibility
rate,
refusal
rate,
and
overall
response
rate.
The
overall
completion
rate
is
calculated
as
the
product
of
the
completion
rate
at
each
stage.
57
%
59
984
,
1
229
943
x
%
100
fielded
#
ineligible
#
completes
screener
#
x
%
100
rate
completion
Screener
=
+
=
+
=

90%
172
,
1
060
,
1
x
100%
ineligible
#
screener
completing
eligible
#
ineligible
#
collection
data
completing
eligible
#
x
100%
rate
completion
collection
Data
=
=
+
+
=

57
In
the
data
collection
completion
rate,
the
ineligible
cases
are
included
in
both
numerator
and
denominator.
If
the
ineligible
cases
are
not
included,
the
data
collection
completion
rate
drops
from
90
to
88
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
4
The
overall
response
rate
measures
the
response
among
eligible
HUs.
The
number
of
eligible
nonrespondents
must
be
estimated
because
eligibility
cannot
usually
be
established
for
households
that
don't
complete
the
screener.
It
is
assumed
that
the
eligibility
rate
among
HUs
whose
eligibility
is
unknown
is
the
same
as
for
HUs
that
did
complete
the
screener.
The
eligibility
rate
among
HUs
that
completed
a
screener
was
81
percent.
The
refusal
rate
is
the
rate
of
refusal
among
HUs
where
contact
was
established.

(
Numerous
attempts
were
made
to
gain
cooperation.
Among
respondents,
two­
thirds
cooperated
on
the
first
or
second
attempt.
While
the
average
number
of
attempts
to
complete
was
2.6,
some
housing
units
didn't
cooperate
until
the
eleventh
attempt.)
HUs
that
were
vacant
or
couldn't
be
located,
that
had
no
one
at
home,
that
were
in
a
locked,
gated
community
where
access
couldn't
be
gained,
or
that
couldn't
otherwise
be
contacted
were
subtracted
from
the
total
sample
size
of
1,984
in
the
denominator.
The
overall
response
rate
for
the
survey
was
51.7
percent.

Eligibility
Rate
#
Eligible
943
100%
x
100%
x
81%
#
Eligible
#
Ineligible
943
229
=
=
=
+
+

Refusal
Rate
#
of
refusals
564
100%
x
100%
x
34.5%
#
contacted
1,634
=
=
=

Overall
Response
Rate
#
eligible
completing
data
collection
100%
x
#
eligible
completing
data
collection
#
eligible
nonrespondents
=
+

831
51.7%
831
(
149
.81*
775)
=
=
+
+

Overall
completion
rates
by
Census
Division
and
block
group
characteristics
such
as
race/
ethnicity,
housing
age,
and
type
of
housing
are
presented
in
Table
7.1.
Mean
percents
for
several
characteristics
by
completion
status
are
given
in
Table
7.2.
For
housing
age,
the
predominant
building
age
category
for
the
block
group
was
assigned
to
the
HU,
except
when
HU
age
was
available
from
survey
respondents.
It
is
important
to
keep
in
mind
that
(
with
the
exception
of
HU
age)
the
characteristics
apply
only
to
the
block
group
in
which
the
HU
is
located,
and
may
not
apply
to
the
HU
itself.
The
associations
between
completion
status
and
these
characteristics
were
tested
using
chi­
square
and
t­
tests
that
take
into
account
the
HU
weights
and
the
survey
design.

Significant
associations
were
found
between
completion
status
and
percents
Hispanic
and
African
American,
percent
below
the
federal
poverty
level,
housing
age,
and
tenure
(
see
Table
7.2).
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
5
Different
completion
rates
for
groups
within
a
category
cannot
always
be
explained,
but
could
be
due
to
factors
such
as
the
use
of
incentives,
attitudes
of
householders,
etc.
In
Table
7.1,
the
highest
response
rates
were
found
among
HUs
in
block
groups
with
30
percent
or
more
Hispanic
population,
30
percent
or
more
in
poverty,
and
in
newer
housing
(
1978
or
later).
The
differences
in
response
rates
are
substantial
for
these
characteristics,
ranging
from
9
to
14
percentage
points
or
more
(
possibly
a
function
of
the
$
200
incentive
having
greater
value
for
these
households).
This
means
that
if
the
lead
outcome
variables
are
correlated
with
any
of
these
characteristics
(
such
as
housing
age),
a
greater
potential
for
nonresponse
bias
would
exist
had
these
characteristics
not
been
used
in
adjusting
for
nonresponse
at
the
screener
and
data
collection
stages.
Nonresponse
adjustment
factors
were
calculated
within
cells
defined
by
the
block
group
percent
of
low­
income
population,
percent
of
Hispanic
or
African
American
population,
and
percent
of
pre­
1940
and
pre­
1960
housing.
In
addition,
the
nonresponse­
adjusted
HU
weights
were
poststratified
to
1997
AHS
housing
unit
totals
by
Census
region,
housing
unit
age,
and
presence
of
a
child
under
18.
Use
of
the
final
adjusted
weights
in
all
analyses
therefore
greatly
reduces
this
potential
bias
in
estimates
for
the
national
housing
stock.

The
presence
or
absence
of
a
household
member
name
on
the
advance
letter
was
also
significantly
correlated
with
completion
rates.
For
HUs
located
in
higher
income
block
groups
(
i.
e.
fewer
than
30
percent
of
the
households
are
below
the
federal
poverty
level),
the
response
rate
for
HUs
with
a
name
on
the
advance
letter
was
significantly
lower
(
p
=
.01)
than
for
HUs
receiving
a
letter
addressed
to
"
Current
Resident"
(
48%
vs.
56%).
For
HUs
located
in
lower
income
block
groups
(
i.
e.
more
than
30
percent
of
the
households
are
below
the
federal
poverty
level),
however,
the
completion
rates
were
not
significantly
different.

Response
rates
for
the
play
areas
sample
were
also
calculated
using
the
above
formula.

Weighted
and
unweighted
response
rates
were
examined
in
the
same
manner,
but
given
the
smaller
sample
size
the
characteristics
were
restricted
to
Census
Region,
building
age
category,
and
soil
lead.
The
national
response
rate
for
the
play
areas
survey
was
79.5
percent
weighted
and
78.0
percent
unweighted
(
higher
than
the
national
survey
since
we
were
returning
to
previously
willing
HUs).
For
each
subset,
the
response
rate
remained
between
71
and
85
percent.
None
of
the
response
rate
differences
observed
for
the
play
areas
survey
were
statistically
significant
at
the
alpha
=
.10
level.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
6
Table
7.1
Completion
Rates
by
1990
Census
Block
Group
Characteristics
Unweighted
Weighted
P­
Value
for
1990
Census
Block
Group
Characteristic
Number
of
HUs
Completion
Rate
Completion
Rate
Chi­
square
testa
Census
Division
New
England
102
52%
53%
0.42
Middle
Atlantic
289
53%
49%
East
North
Central
289
49%
46%
West
North
Central
181
55%
55%
South
Atlantic
326
52%
53%
East
South
Central
144
53%
54%
West
South
Central
208
56%
58%
Mountain
136
57%
58%
Pacific
309
56%
57%
%
Hispanic
Population
Less
than
30%
Hispanic
1832
52%
52%
0.005
30%
or
more
Hispanic
152
65%
65%
%
African
American
Population
Less
than
30%
African
American
1731
52%
53%
0.08
30%
or
more
African
American
253
60%
59%
%
Population
in
Poverty
Less
than
30%
in
Poverty
1796
53%
52%
0.04
30%
or
more
in
Poverty
188
60%
61%
%
Multi­
family
Housing
Units
(
5+)
Less
than
30%
Multi­
family
HUs
1522
53%
53%
0.42
30%
or
more
Multi­
family
HUs
462
56%
55%
Age
of
Housing
Unitb
Pre­
1940
456
48%
45%
<
0.001
1940
 
1959
363
59%
60%
1960
 
1977
806
47%
45%
1978
and
later
359
70%
74%

a
Chi­
square
test
between
completion
rate
and
housing
characteristic
­
takes
into
account
the
HU
weights
and
sample
design.

b
Reported
HU
age
used
when
available
for
HUs
completing
screener.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
7
Table
7.2
Mean
Percents
for
Completed
and
Noncompleted
Housing
Units
by
1990
Census
Block
Group
Characteristics
Mean
of
Characteristic
1990
Census
Block
Group
Characteristic
Completes
Noncompletes
P­
value
for
t­
test
between
completes
and
noncompletesa
Percent
HUs
Pre­
1940b
18%
25%
0.001
Percent
Population
below
Poverty
Level
12%
11%
0.080
Percent
Multi­
Family
HUs
(
5+)
17%
16%
0.535
Percent
Multi­
Family
HUs
(
20+)
7%
7%
0.908
Percent
HUs
Owned
63%
66%
0.042
Percent
Population:
African
American
11%
8%
0.006
Percent
Population:
Hispanic
8%
5%
0.005
a
The
test
takes
into
account
the
HU
weights
and
sample
design.

b
HU
age
reported
by
respondents
was
used
when
available
for
HUs
completing
screener.

7.2.2
Comparison
of
"
Hard­
to­
Recruit"
Versus
"
Easy­
to­
Recruit"
HUs
Lead
measurements
were
not
available
for
the
HUs
whose
occupants
refused
to
participate
in
the
survey
or
who
could
not
be
contacted,
so
it
is
not
possible
to
know
how
their
participation
would
have
changed
the
estimates
of
lead
prevalence
in
housing.
However,
if
the
HUs
that
initially
refused
but
later
cooperated
(
or
those
HUs
requiring
several
attempts
to
complete
the
screener)
are
similar
to
the
survey
nonrespondents,
they
may
be
considered
as
a
proxy
group
for
the
nonrespondents.
If
they
are
significantly
different,
this
may
indicate
the
likely
direction
of
the
nonresponse
bias
in
the
lead
prevalence
estimates.

The
initial
refusals
were
compared
with
HUs
with
a
history
of
no
refusal.
HUs
requiring
4
or
more
attempts
to
complete
the
screener
were
also
compared
with
those
requiring
3
or
fewer
attempts.
The
number
of
attempts
was
split
at
3­
4
for
two
reasons.
Two­
thirds
of
respondents
cooperated
on
the
first
or
second
attempt
and
the
average
number
of
attempts
to
complete
was
2.6.
The
comparisons
were
made
for
four
key
statistics
and
by
the
housing
characteristics
recorded
by
the
interviewer.
The
statistics
were
1)
the
presence
of
LBP
anywhere
in
the
home,
2)
the
presence
of
deteriorated
LBP
anywhere
in
the
home,
3)

presence
of
LBP
hazard
anywhere
in
the
home,
and
4)
the
presence
of
a
soil
lead
hazard.
The
housing
characteristics
were
the
respondent's
race/
ethnicity,
household
income,
tenure,
building
age,
and
presence
of
a
child
under
18.
Comparison
of
whether
or
not
the
household
had
initially
refused
(
or
required
more
than
three
attempts
to
obtain
a
completed
screener)
and
these
characteristics
is
presented
in
Table
7.3.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
8
Table
7.3
Comparison
of
"
Easy­
to­
Recruit"
Respondents
Versus
"
Hard­
to­
Recruit"
Respondents
National
Survey
Estimates
Initial
Refusal
(%)
p­
valuea
More
than
3
Attempts
to
Complete
Screener
(%)
p­
valuea
Presence
of
LBP
anywhere
in
HU
Yes
9.2
0.60
17.3
0.67
No
10.0
15.1
Presence
of
Significantly
Deteriorated
LBP
anywhere
Yes
6.0
0.05
12.8
0.29
No
10.4
16.7
Presence
of
Significant
LBP
Hazard
in
HU
Yes
5.6
0.0007
15.8
0.84
No
11.6
16.5
Presence
of
Soil­
Lead
Hazard
Yes
8.7
0.85
6.2
0.29
No
9.9
16.7
Ethnicity
Hispanic
10.7
0.78
9.6
0.14
Non­
Hispanic
9.7
16.8
Race
White
10.2
0.38
16.9
0.12
African
American
6.7
11.7
Asian,
Pacific
Islander,
Hawaiian,
8.9
14.4
American
Indian,
Other
Presence
of
Child
under
18
Yes
9.9
0.85
15.1
0.31
No
9.5
16.6
Year
of
Construction
Pre­
1940
7.2
0.22
18.6
0.18
1940
 
1959
6.1
11.5
1960
 
1977
12.1
13.3
1978
or
later
11.4
20.2
Tenure
(
moved
up
to
be
w/
hsg
info)
Owned
11.2
0.03
15.8
0.15
Rented
6.3
16.8
Type
of
Housing
Single­
family
10.3
0.02
15.4
0.58
Multi­
family
5.8
19.9
Household
Income
Less
than
$
30,000
4.7
<
0.0001
12.3
0.03
$
30,000
or
More
11.7
17.8
Household
Income
Less
than
$
20,000
4.7
0.05
11.1
0.02
$
20,000
­
$
39,999
6.8
15.6
$
40,000
­
$
59,999
10.9
16.8
$
60,000
and
over
13.5
18.9
Poverty
Below
Poverty
Level
4.6
0.003
9.9
0.005
At
or
Above
Poverty
Level
9.8
17.0
a
Chi­
square
test
of
association
between
Ease
of
Recruitment
and
Reported
Housing
Characteristics.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
9
Table
7.3
shows
that
poorer
households
were
much
less
likely
to
have
an
initial
refusal,
and
required
fewer
attempts
to
obtain
a
completed
screener.
This
is
consistent
with
earlier
analysis
showing
higher
response
rates
for
lower
income
households.
It
could
be
that
the
monetary
incentive
was
more
effective
among
lower
income
households
in
improving
response
rates,
or
that
higher
income
HUs
were
more
difficult
to
contact.

Table
7.3
also
shows
that
households
with
LBP,
significantly
deteriorated
LBP,
significant
LBP
hazard,
or
soil
lead
hazard
were
just
as
likely
to
require
more
than
three
attempts
to
complete
the
screener
as
those
without
these
lead
characteristics.
While
households
with
LBP
or
soil
hazards
were
just
as
likely
to
initially
refuse
as
other
households,
those
with
significantly
deteriorated
LBP
or
LBP
hazards
were
significantly
more
likely
to
initially
refuse
than
those
without
these
characteristics.
This
could
be
due
to
the
fact
that
more
lower
income
homes
participated
in
the
survey
and
lower
income
homes
are
more
likely
to
have
these
characteristics.

The
nonresponse
analysis
shows
that
the
households
that
responded
were
more
likely
to
be
located
in
densely
Hispanic
and
low
income
areas,
and
to
be
renters
as
opposed
to
home
owners.
They
are
also
more
likely
to
live
in
newer
housing
(
post­
1977).

If
the
initial
refusals
who
agreed
to
cooperate
are
representative
of
nonrespondents,
there
would
be
a
potential
for
bias
in
unweighted
estimated
prevalence
of
HUs
with
deteriorated
LBP
or
LBP
hazards.
This
means
that
there
would
be
a
potential
for
bias
in
the
estimated
prevalence
of
HUs
with
an
LBP
hazard.
However,
this
was
partially
corrected
by
using
race/
ethnicity,
low­
income
indicators,
and
building
age
in
making
nonresponse
adjustments
to
the
HU
weights.
The
weighting
adjustments
do
not
eliminate
nonresponse
bias
completely,
but
they
do
reduce
it
when
variables
that
are
correlated
with
both
the
response
rates
and
propensity
to
have
a
lead
hazard
are
used
in
the
nonresponse
adjustments.

Comparison
of
the
nonresponse­
adjusted
and
poststratified
weighted
distribution
of
housing
from
the
National
Survey
with
the
AHS
and
CPS
in
Table
2.1
show
that
the
weighted
National
Survey
sample
matches
the
national
housing
distribution
closely.
These
results
suggest
that
there
is
probably
not
a
serious
nonresponse
bias
in
the
weighted
estimates
of
lead
hazard
prevalence.

7.2.3
Completion
Rates
in
the
Play
Area
Subsample
In
the
play
area
subsample,
40
of
the
75
PSU's
were
selected
and
all
previously
completed
homes
were
selected
for
revisiting.
There
were
481
homes
in
the
40
PSU's.
Table
7.4
displays
the
yield
in
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
10
this
subsample.
In
the
play
area
subsample,
78
percent
of
the
homes
were
completed,
either
with
the
collection
of
a
play
area
soil
sample,
or
the
determination
that
one
was
not
necessary.

Table
7.4.
Completions
in
Play
Area
Subsample
Result
Number
of
HUs
Percent
of
HUs
Complete,
no
soil
sample
needed
178
37%
Complete,
new
soil
sample
collected
197
41%
Total
completes
375
78%
No
contact
made
with
respondent
54
11%
Refusal
12
2%
Demolished
1
0%
Vacant
27
6%
Other
12
2%
Total
Housing
Units
481
100%

7.3
Quality
of
Field
Data
Collection
and
Analysis
Quality
assurance
was
integrated
into
all
components
of
the
study,
including
a
defensible
study
design,
experienced
project
personnel,
utilization
of
well­
planned,
detailed
and
tested
protocols
for
all
aspects
of
data
collection,
thorough
study­
specific
training
of
experienced
field
staff,
electronic
sample
and
data
management,
and
ongoing
communication
between
individuals
responsible
for
each
stage
of
the
study.

These
procedures
are
described
in
detail
in
Volume
II,
Chapter
6.

Four
types
of
replicate
sampling
were
conducted
to
estimate
measurement
error:
replicate
XRF
testing
of
one
random
component
per
room,
replicate
dust
sampling
of
one
surface
per
home,
replicate
soil
sampling
at
a
different
sample
site
at
every
third
home,
and
replicate
room
sampling
at
a
subset
of
homes.
The
analyses
utilizing
these
replicate
data
and
resultant
measurement
error
estimates
are
presented
in
Appendix
C.

This
section
summarizes
the
results
of
the
various
activities
focussed
at
ensuring
quality
of
the
field
data
collection
and
laboratory
analysis
of
the
environmental
samples.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
11
7.3.1
Field
Data
Collection
A
number
of
procedures
were
instituted
to
ensure
quality
of
the
field
data
collection,
including
a
manual
edit
of
all
data
and
samples
by
the
field
team,
review
by
the
Field
Supervisor
upon
return
of
the
data
to
Westat
headquarters,
and
reconciliation
of
any
errors
with
the
field
team
prior
to
submission
of
any
samples
to
the
laboratory.
In
addition,
random
telephone
verification
and
field
team
audits
were
conducted;

dust
sample
material
screens
were
analyzed;
and
dust
blanks
and
spike
samples
and
blind
soil
reference
samples
were
included
in
the
sample
stream.

Telephone
Verification
of
Data
Collection
The
Field
Director
contacted
a
random
subsample
of
82
(
10%)
households
by
telephone
to
verify
the
team's
activities
and
conduct
and
to
validate
selected
information
from
the
data
forms.
No
field
problems
were
identified
by
this
process.

In
addition
to
the
random
verification
process,
a
number
of
respondents
and
potential
respondents
utilized
the
toll­
free
phone
number,
or
the
HUD
phone
number,
to
ask
questions,
verify
the
survey,
and
express
concerns.
All
questions
or
concerns
were
answered
or
addressed
by
the
Field
Director
or
HUD.

Random
Field
Audits
The
QA
Officer
or
designee,
and
HUD
and
NIEHS
representatives,
conducted
random
field
audits
at
31
households
to
verify
that
the
protocols
were
followed
and
data
collection
was
accurate
and
complete.
In
addition
to
the
field
audits,
the
QA
Officer
conducted
17
telephone
audits
to
ascertain
the
team
members'
understanding
of
the
protocols,
especially
when
more
than
two
months
had
elapsed
between
assignments.
Problems
noted
during
these
audits
were
corrected
directly
with
the
individual
team
members.

In
addition,
the
results
of
audits
were
immediately
relayed
to
the
Field
Office.
As
appropriate,
all
field
staff
were
notified
by
memo
of
any
issues
identified
with
the
protocols.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
12
Lead
Dust
Wipe
Sample
Collection

Lead
Dust
Wipe
Materials
Screens
The
purpose
of
a
materials
screen
was
to
verify
that
the
various
sampling
supplies
to
be
used
in
the
field
did
not
have
lead
contamination.
Two
screens
were
prepared
and
analyzed
for
every
lot
of
wipe
materials
and
sample
tubes
before
being
used
in
the
study.
The
analyses
showed
that
all
material
screens
had
below
1.5
µ
g
lead.
58

Field
Blank
Wipes
One
field
blank
wipe
was
prepared
for
each
HU
at
a
specified
random
sample
location
where
another
wipe
sample
was
collected.
All
field
blanks
were
below
50
µ
g
lead/
wipe,
as
specified
in
HUD
Guidelines.
Most
field
blanks
(
98+%
of
all
field
blanks)
had
lead
levels
below
the
detection
limit
for
the
analytical
run
(
approximately
3.5
µ
g
lead/
wipe).
Of
15
field
blanks
with
lead
values
above
3.5
µ
g
lead/
wipe,
only
one
blank
had
more
than
20
µ
g
lead/
wipe;
this
wipe
had
43
µ
g
lead
and
was
collected
in
a
home
with
elevated
window
sill
and
trough
lead
dust
levels.
Data
from
this
home
were
used
in
the
survey
since
the
blank
was
still
below
the
50
µ
g
guideline.


Reference
(
Spike)
Sample
Dust
Wipes
Reference
wipe
samples
were
made
in
advance
of
the
fieldwork
by
placing
a
known
quantity
of
National
Institute
of
Standards
and
Technology's
Standard
Reference
Material
(
NIST
SRM)
1579a
on
the
same
wipe
material
used
in
the
study.
The
reference
wipes
were
labeled
like
a
regular
sample
so
that
the
laboratory
was
blinded
to
fact
that
these
were
quality
control
samples.
The
Field
Office
inserted
one
reference
wipe
sample
with
each
group
of
50
samples
before
sending
samples
to
the
laboratory.
A
total
of
206
reference
wipes,
ranging
from
21
to
516
µ
g
lead/
wipe,
were
submitted
over
the
course
of
the
study.

The
average
reference
sample
recovery
was
96%
(
range
from
83%
to
115%)
with
a
standard
deviation
of
+

5.25
percent.
With
a
few
exceptions,
all
sample
recoveries
were
within
the
HUD
Guidelines
acceptable
range
of
80
to
120
percent.
The
laboratory
was
requested
to
re­
analyze
those
batches
with
values
outside
acceptable
limits.
Recoveries
were
acceptable
on
the
second
run
(
see
Section
6.7
of
Volume
II)
and
the
second
set
of
data
was
used
for
the
entire
batch
of
samples.

58
EPA's
National
Lead
Laboratory
Accreditation
Program
(
NLLAP)
requires
wipes
to
be
used
in
the
field
to
have
less
than
5
µ
g
lead/
wipe.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
13
Soil
Quality
Control
Samples

Reference
Soil
Samples
Reference
soil
samples
were
purchased
before
the
fieldwork
began.
The
Field
Office
labeled
and
included
one
reference
sample
with
each
group
of
samples
from
every
three
households
(
approximately
one
sample
in
ten).
A
total
of
83
soil
reference
samples
were
submitted
to
the
laboratory.
The
average
recovery
was
104%
(
range
84%
to
121%)
with
a
standard
deviation
of
+
8.04
percent.
Two
analytical
batches
contained
a
reference
sample
with
a
recovery
of
121%,
exceeding
the
control
limits
of
80
to
100
percent.
The
laboratory
was
requested
to
re­
analyze
these
batches.
Recoveries
were
acceptable
on
the
second
run
(
see
Section
6.9,
Volume
II)
and
the
second
set
of
data
was
used
for
the
entire
batch
of
samples.

Two
types
of
reference
soil
samples
were
used:
urban
soil
provided
by
University
of
Cincinnati
(
640,
3,132,
and
6,090
ppm
lead),
and
NIST
SRM
2709
(
San
Joacquin
soil,
18.9
ppm
lead)
and
SRM
2711
(
Montana
soil,
1,162
ppm
lead).
It
is
interesting,
but
not
unexpected,
that
the
average
recovery
of
89%
for
the
NIST
Montana
soil
was
lower
than
the
average
of
105%
for
the
urban
soils.
Lead
in
urban
soils
tends
to
be
from
more
leachable
sources
(
i.
e.
paint,
past
automobile
emissions,
industrial
facilities).
59
7.3.2
Laboratory
Quality
Control
Samples
Each
laboratory
provided
quality
assurance
procedures
during
the
selection
and
qualification
process.
These
approved
procedures
(
outlined
in
the
National
Survey's
Protocol
and
Sample
Design
Report,
June,
1999)
were
adhered
to
for
all
study
samples.
In
general,
the
laboratories
performed
instrumental
and
duplicate
quality
control
analyses,
as
required
by
ASTM
E
1613­
94
and
the
American
Industrial
Hygiene
Association's
Environmental
Lead
Laboratory
Accreditation
Program
(
ELLAP)
Quality
Manual
and
Policies,
to
ensure
that
the
original
calibration
solutions
were
accurate,
the
instruments
were
properly
zeroed,
instrumental
drift
was
not
excessive,
and
carryover
between
samples
did
not
occur.
These
included
duplicate
injections
of
the
same
sample,
method
blanks,
and
spiked
samples
at
a
minimum
frequency
of
five
percent
of
the
samples.

59
Personal
communication
with
Sandy
Roda,
Director,
Hematology
and
Environmental
Laboratory,
University
of
Cincinnati.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
October
31,
2002
7­
14
7.3.3
Laboratory
Selection
Quality
Assurance
The
laboratories
used
for
analysis
of
dust
and
soil
samples,
respectively,
were
recognized
by
the
EPA
under
its
National
Lead
Laboratory
Accreditation
Program
(
NLLAP)
for
those
analyses
throughout
the
laboratory
qualification
and
performance
phases
of
the
National
Survey.
This
recognition
provided
assurance
of
the
quality
of
laboratory
performance
of
lead
analyses
and
reporting.
In
addition,

the
laboratories
were
accredited
by
the
American
Industrial
Hygiene
Association;
this
accreditation
provided
a
separate
assurance
of
the
quality
of
laboratory
management
and
performance
of
environmental
analyses
and
reporting.

7.4
Paint
Testing
Quality
Assurance
Calibration
of
the
XRF
analyzer
was
performed
before
and
after
testing
in
every
home.
In
no
case
was
the
instrument
used
if
the
calibration
criteria
were
not
met,
i.
e.
the
analyzer
read
0.0
mg/
m2
on
the
0.0
film
and
between
0.9
and
1.2
mg/
m2
on
both
the
front
and
back
of
the
1.0
film.
In
addition,
the
average
of
three
readings
on
the
front
of
the
1.0
film
was
between
0.9
and
1.2
mg/
m2.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
1
October
31,
2002
APPENDIX
A
Selected
Additional
Tables
and
Figures
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
2
October
31,
2002
Figure
A.
1
Prevalence
of
Significant
LBP
Hazards,
Soil
Lead
Threshold
at
2,000
ppm
and
at
1,200
ppm
0
5,000
10,000
15,000
20,000
25,000
30,000
All
Occupied
Housing
Units
Midwest
West
Built
1960­
1977
Built
Before
1940
Income
<
$
30,000/
year
African
American
Household
Households
with
Children
<
6
Years
Subpopulation
of
Housing
Units
Housing
Units
(
000)
with
Significant
LBP
Hazards
2,000
ppm
1,200
ppm
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
3
October
31,
2002
Table
A.
1
Prevalence
of
Housing
Units
with
Significant
Lead­
Based
Paint
(
LBP)
Hazards,
by
Selected
Characteristics,
for
Alternative
Soil
Lead
Threshold
of
2000
ppm
HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazardsa
Characteristic
All
HUs
(
000)
b
No.
of
HUs
with
Significant
LBP
Hazards
(
000)
Percent
of
HUs
with
Significant
LBP
Hazards
(%)
c
HUs
in
Sample
Estimate
Lower
95%
CId
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Total
Occupied
HUs
95,688
25,517
20,410
30,623
27%
21%
32%
375
Region:
Northeast
19,290
8,260
5,904
10,616
43%
31%
55%
95
Midwest
22,083
7,606
5,691
9,521
34%
26%
43%
102
South
35,474
6,082
3,161
9,003
17%
9%
25%
111
West
18,841
3,569
1,003
6,135
19%
5%
33%
67
Construction
Year:
1978­
1998
29,774
425
0
1,222
1%
0%
4%
88
1960­
1977
27,874
2,843
317
5,370
10%
1%
19%
111
1940­
1959
20,564
10,501
7,996
13,006
51%
39%
63%
97
Before
1940
17,476
11,747
8,771
14,723
67%
50%
84%
79
Urbanization
MSA
>=
2
million
population
26,814
6,793
4,978
8,609
25%
19%
32%
276
MSA
=<
2
million
population
45,753
10,232
8,171
12,293
22%
18%
27%
417
Non­
MSA
23,121
7,001
3,848
10,153
30%
17%
44%
138
One
or
More
Children
Under
Age
6:
All
HU
ages
16,402
5,652
3,758
7,546
34%
23%
46%
83
HUs
built
1978­
1998
5,847
364
0
1,127
6%
0%
19%
25
HUs
built
1960­
1977
5,098
371
0
987
7%
0%
19%
20
HUs
built
1940­
1959
3,055
2,662
1,554
3,770
87%
51%
123%
22
HUs
built
before
1940
2,401
2,255
502
4,007
94%
21%
167%
16
Housing
Unit
Type:
Single
family
82,651
23,204
17,794
28,614
28%
22%
35%
319
Multi­
family
13,037
2,313
0
5,143
18%
0%
39%
56
Occupant
Status:
Owner­
occupied
62,232
16,013
12,647
19,380
26%
20%
31%
254
Renter­
occupied
29,074
9,503
5,906
13,100
33%
20%
45%
119
Refusal/
Don't
Knowe
381
2
Household
Income:
Less
than
$
30,000/
year
33,830
13,998
8,938
19,057
41%
26%
56%
145
Equal
to
or
more
than
$
30,000/
year
56,111
10,060
7,151
12,970
18%
13%
23%
211
Refusal/
Don't
Know
5,747
19
One
or
More
Children
Under
Age
6:
All
Income
Categories
16,402
5,652
3,758
7,546
34%
23%
46%
83
Less
than
$
30,000/
year
4,791
1,646
0
3,460
34%
0%
72%
28
Equal
to
or
more
than
$
30,000/
year
11,236
4,006
1,797
6,214
36%
16%
55%
52
Refusal/
Don't
Know
375
3
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
4
October
31,
2002
Table
A.
1
Prevalence
of
Housing
Units
with
Significant
Lead­
Based
Paint
(
LBP)
Hazards,
by
Selected
Characteristics,
for
Alternative
Soil
Lead
Threshold
of
2000
ppm
(
continued)

HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazardsa
Characteristic
All
HUs
(
000)
b
No.
of
HUs
with
Significant
LBP
Hazards
(
000)
Percent
of
HUs
with
Significant
LBP
Hazards
(%)
c
HUs
in
Sample
Estimate
Lower
95%
CId
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Government
Support:
Government
support
4,809
822
10
1,634
17%
0%
34%
25
No
government
support
86,070
23,571
19,114
28,028
27%
22%
33%
327
Refusal/
Don't
Know
4,809
23
Poverty:
In
Poverty
13,221
5,053
2,542
7,565
38%
19%
57%
54
Not
in
Poverty
76,336
18,669
14,396
22,942
24%
19%
30%
300
Refusal/
Don't
Know
6,130
21
Race:
White
77,005
19,164
14,972
23,356
25%
19%
30%
285
African
American
10,365
2,317
665
3,969
22%
6%
38%
45
Otherf
6,571
2,631
0
5,734
40%
0%
87%
35
Refusal/
Don't
Know
1,746
10
Ethnicity:
Hispanic/
Latino
7,434
3,635
700
6,569
49%
9%
88%
31
Not
Hispanic/
Latino
87,008
20,841
16,734
24,948
24%
19%
29%
337
Refusal/
Don't
Know
1,246
7
a
Significant
LBP
hazard
as
defined
in
text
and
HUD
Lead
Safe
Housing
Rule.
b
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
c
All
percentages
are
calculated
with
the
"
All
HUs"
column
in
each
row
used
as
the
denominator.
d
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
e
Refusals
and
"
don't
know"
responses
by
survey
respondents.
f
"
Other"
race
includes
Asian,
American
Indian
or
Alaskan
Native,
Native
Hawaiian
or
other
Pacific
Islander,
and
more
than
one
race.

Table
A.
2
Prevalence
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
by
Location
in
the
Building,
for
Alternative
Soil
Lead
Threshold
of
2000
ppm
HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazards
LBP
Hazard
Location
Number
of
HUsa
(
000)
Percent
of
HUsb
HUs
in
Sample
Estimate
Lower
95%
CIc
Upper
95%
CI
Percent
Lower
95%
CI
Upper
95%
CI
Interior
only
10,861
6,865
14,857
11%
7%
16%
47
Both
Interior
and
Exterior
7,965
4,891
11,040
8%
5%
12%
39
Exterior
only
6,690
3,635
9,745
7%
4%
10%
29
Anywhere
25,517
20,440
30,594
27%
21%
32%
115
No
Significant
LBP
Hazard
70,171
65,094
75,248
73%
68%
79%
260
Total
HUs
95,688
100%
375
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
5
October
31,
2002
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
Percentages
may
not
total
100%
due
to
rounding.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

Table
A.
3
Prevalence
of
Significant
Lead­
Based
Paint
(
LBP)
Hazards
in
Housing
Units
with
a
Child
Under
6
Years
of
Age
by
Type
of
Hazard,
for
Alternative
Soil
Lead
Threshold
of
2000
ppm
HUD
Lead
Safe
Housing
Rule:
Significant
LBP
Hazards
Type
of
Hazard
Number
of
HUsa
(
000)
Percent
of
HUsb
(%)

Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Significantly
Deteriorated
Lead
Based
Paint
All
HUs
14,124
10,666
17,582
15%
11%
18%
HUs
w/
Child
Under
6
3,521
1,576
5,467
21%
10%
33%
Interior
Lead
Dust
All
HUs
16,794
12,169
21,420
18%
13%
22%
HUs
w/
Child
Under
6
3,637
1,636
5,638
22%
10%
34%
Lead
Contaminated
Soil
All
HUs
5,572
2,487
8,657
6%
3%
9%
HUs
w/
Child
Under
6
1,419
0
3,057
9%
0%
19%
Any
LBP
Hazard
All
HUs
25,517
20,410
30,623
27%
21%
32%
HUs
w/
Child
Under
6
5,652
3,758
7,546
34%
23%
46%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
Percentages
are
calculated
with
total
housing
units
(
95,688)
or
with
housing
units
with
a
child
under
age
6
(
19,577)
as
the
denominator,
or
as
applicable.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
6
October
31,
2002
Table
A.
4a
Distribution
of
Single
Family
Housing
Units
(
SFHUs)
with
Deteriorated
or
Significantly
Deteriorated
Paint,
by
Construction
Year
Deteriorated
Paint
Construction
Year
Total
SFHUs
(
000)
a
Number
of
SFHUs
with
Deteriorated
Paint
(
000)
Percent
of
SFHUs
with
Deteriorated
Paint
(%)
b
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
1978­
1998
26,349
5,231
2,628
7,835
20%
10%
30%
1960­
1977
22,657
7,992
5,573
10,410
35%
25%
46%
1940­
1959
18,497
11,987
9,643
14,331
65%
52%
77%
Before
1940
15,148
11,518
10,049
12,986
76%
66%
86%
Total
SFHUs
82,651
36,728
27,893
45,562
44%
34%
55%

Significantly
Deteriorated
Paint
Construction
Year
Total
SFHUs
(
000)
No.
of
SFHUs
with
Significantly
Deteriorated
Paint
(
000)
Percent
of
SFHUs
with
Significantly
Deteriorated
Paint
(%)

Estimate
Lower
95%
CI
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
1978­
1998
26,349
3,403
1,629
5,176
13%
6%
20%
1960­
1977
22,657
6,606
4,291
8,922
29%
19%
39%
1940­
1959
18,497
9,426
7,240
11,611
51%
39%
63%
Before
1940
15,148
9,365
7,527
11,203
62%
50%
74%
Total
SFHUs
82,651
28,800
20,686
36,913
35%
25%
45%

a
"
Single
family
housing
units"
include
permanently
occupied,
noninstitutional
single
family
housing
units
in
which
children
are
permitted
to
live.
b
Percentages
are
calculated
with
total
housing
units
(
95,688)
or
with
housing
units
with
a
child
under
age
6
(
19,577)
as
the
denominator,
or
as
applicable.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
7
October
31,
2002
Table
A.
4b
Distribution
of
Single
Family
Housing
Units
(
SFHUs)
with
Deteriorated
or
Significantly
Deteriorated
Unleaded
Paint,
by
Construction
Year
Deteriorated
Unleaded
Paint
Construction
Year
Total
SFHUs
(
000)
a
Number
of
SFHUs
with
Deteriorated
Unleaded
Paint
(
000)
Percent
of
SFHUs
with
Deteriorated
Unleaded
Paint
(%)
b
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
1978­
1998
26,349
5,149
2,525
7,773
20%
10%
29%
1960­
1977
22,657
7,081
4,873
9,289
31%
22%
41%
1940­
1959
18,497
5,748
4,076
7,420
31%
22%
40%
Before
1940
15,148
2,824
1,828
3,819
19%
12%
25%
Total
SFHUs
82,651
20,802
13,303
28,301
25%
16%
34%

Significantly
Deteriorated
Unleaded
Paint
Construction
Year
Total
SFHUs
(
000)
2
No.
of
SFHUs
with
Significantly
Deteriorated
Unleaded
Paint
(
000)
Percent
of
SFHUs
with
Significantly
Deteriorated
Unleaded
Paint
(%)
1
Estimate
Lower
95%
CI3
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
1978­
1998
26,349
3,320
1,521
5,119
13%
6%
19%
1960­
1977
22,657
5,997
3,752
8,241
26%
17%
36%
1940­
1959
18,497
4,658
3,107
6,209
25%
17%
34%
Before
1940
15,148
2,250
1,274
3,225
15%
8%
21%
Total
SFHUs
82,651
16,225
9,654
22,795
20%
12%
28%

a
"
Single
family
housing
units"
include
permanently
occupied,
noninstitutional
single
family
housing
units
in
which
children
are
permitted
to
live.
b
Percentages
are
calculated
with
total
housing
units
(
95,688)
or
with
housing
units
with
a
child
under
age
6
(
19,577)
as
the
denominator,
or
as
applicable.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
8
October
31,
2002
Table
A.
4c
Distribution
of
Single
Family
Housing
Units
(
SFHUs)
with
Deteriorated
and
Significantly
Deteriorated
Lead­
Based
Paint
(
LBP)
by
Construction
Year
Deteriorated
LBP
Construction
Year
Number
of
SFHUs
with
Deteriorated
LBP
(
000)
Percent
of
SFHUs
with
Deteriorated
LBP
(%)
1
Total
SFHUs
(
000)
2
Estimate
Lower
95%
CI3
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
1978­
1998
26,349
83
0
238
0%
0%
1%
1960­
1977
22,657
910
242
1,579
4%
1%
7%
1940­
1959
18,497
6,239
4,319
8,159
34%
23%
44%
Before
1940
15,148
8,694
7,107
10,281
57%
47%
68%
Total
SFHUs
82,651
15,926
11,668
20,257
19%
14%
25%

Significantly
Deteriorated
LBP
Construction
Year
No.
of
SFHUs
with
Significantly
Deteriorated
LBP
(
000)
Percent
of
SFHUs
with
Significantly
Deteriorated
LBP
(%)
1
Total
SFHUs
(
000)
2
Estimate
Lower
95%
CI3
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
1978­
1998
26,349
83
0
238
0%
0%
1%
1960­
1977
22,657
610
97
1,122
3%
0%
5%
1940­
1959
18,497
5,002
3,193
6,811
27%
17%
37%
Before
1940
15,148
7,115
5,605
8,626
47%
37%
57%
Total
SFHUs
82,651
12,809
8,894
16,797
15%
11%
20%

a
"
Single
family
housing
units"
include
permanently
occupied,
noninstitutional
single
family
housing
units
in
which
children
are
permitted
to
live.
b
Percentages
are
calculated
with
total
housing
units
(
95,688)
or
with
housing
units
with
a
child
under
age
6
(
19,577)
as
the
denominator,
or
as
applicable.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.

Table
A.
5
Estimated
Number
of
Housing
Units
with
Lead­
Based
Paint
on
Windows
Number
of
Housing
Units
with
LBP
Windows
(
000)

HU
Characteristic
Estimate
Lower
95%
CI
Upper
95%
CI
HUs
in
Sample
All
Housing
Units
18,222
15,688
20,757
165
Construction
Year:
1978­
1998
290
0
711
2
1960­
1977
2,092
1,251
2,933
20
1940­
1959
4,733
3,202
6,264
41
Before
1940
11,108
9,298
12,917
102
Occupied
by
Children
Under
Age
6
2,826
1,661
3,991
32
Household
in
Poverty
3,547
2,324
4,771
36
Household
in
Poverty,
Resident
Children
Under
Age
6
569
169
969
7
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
9
October
31,
2002
Table
A.
6
Estimated
Number
of
Windows
with
Lead­
Based
Paint
and
in
Housing
Units
with
Lead­
Based
Paint
on
Windows
Number
of
Windows
with
Lead­
Based
Paint
(
Average/
HU)
a
Number
of
Painted
Windows
(
Average/
HU)
Total
Number
of
Windows
(
Average/
HU)

HU
Characteristic
Estimate
Lower
95%
CI
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
All
Housing
Units
7.7
6.2
9.3
13.9
12.1
15.7
15.0
13.3
16.8
Construction
Year:
1978­
1998
3.5
0.0
7.9
7.2
3.9
10.4
7.2
3.9
10.4
1960­
1977
5.6
3.4
7.8
14.0
8.1
20.0
14.4
8.5
20.3
1940­
1959
6.5
4.2
8.7
12.8
10.6
15.0
14.0
12.0
16.1
Before
1940
8.7
6.9
10.6
14.5
12.5
16.5
15.7
13.8
17.7
Occupied
by
Children
Under
Age
6
12.7
8.0
17.5
20.4
14.5
26.3
21.8
16.2
27.4
Household
in
Poverty
4.3
2.7
6.0
7.9
5.9
9.9
9.4
8.1
10.7
Household
in
Poverty,
Resident
Children
Under
Age
6
4.8
0.7
8.8
9.8
7.8
11.9
9.8
7.8
11.9
a
Entries
are
average
number
of
windows
per
housing
units,
averaged
over
the
housing
units
with
LBP
on
windows.

Table
A.
7
Distribution
of
Maximum
Soil
Sample
(
Bare
and
Covered)
Lead
Concentrations,
All
Sampled
Locations
Bare
Soil
Lead
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Estimate
Lower
95%
CIc
Upper
95%
CI
Estimate
Lower
95%
CI
Upper
95%
CI
GEd0
ppm
93,111
91,090
95,131
97%
95%
99%
GE
20
ppm
74,621
68,764
80,478
78%
72%
84%
GE
50
ppm
56,266
49,840
62,693
59%
52%
66%
GE
200
ppm
29,234
28,240
30,228
31%
30%
32%
GE
400
ppm
20,390
17,032
23,748
21%
18%
25%
GE
1,200
ppm
11,145
7,580
14,709
12%
8%
15%
GE
1,600
ppm
7,426
5,289
9,563
8%
6%
10%
GE
2,000
ppm
6,809
4,535
9,084
7%
5%
10%
GE
5,000
ppm
2,987
1,548
4,427
3%
2%
5%
No
Bare
Soil
335
0
960
0%
0%
1%
No
Soil
2,242
330
4,154
2%
0%
4%
Missinge
95,688
a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
(
95,688)
as
the
denominator.
c
CI
=
95%
confidence
interval
for
the
estimated
number
or
percent.
d
GE
equals
"
greater
than
or
equal
to."
e
"
Missing"
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
either
the
sample
was
not
collected,
e.
g.
due
to
inaccessibility
or
respondent
refusal,
or
the
laboratory
did
not
submit
a
value).
"
No
soil"
means
that
there
was
no
soil
on
the
property
to
sample.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
A­
10
October
31,
2002
Table
A.
8
Distribution
of
Maximum
Soil
Sample
(
Bare
and
Covered)
Lead
Concentrations
by
Construction
Year,
All
Sampled
Locations
Soil
Lead
Concentration
Number
of
HUs
(
000)
a
Percent
of
HUs
(%)
b
Before
1940
1940
­
1959
1960
­
1977
1978
­
1998
Before
1940
1940
­
1959
1960
­
1977
1978
­
1998
GEc
0
ppm
16,328
19,605
27,608
29,569
93%
95%
99%
99%
GE
20
ppm
16,328
19,279
25,238
13,776
93%
94%
91%
46%
GE
50
ppm
15,820
17,670
14,092
8,684
91%
86%
51%
29%
GE
200
ppm
13,314
9,950
4,495
1,476
76%
48%
16%
5%
GE
400
ppm
11,613
6,283
2,410
84
67%
31%
9%
0%
GE
1,200
ppm
6,536
3,922
686
­
37%
19%
3%
0%
GE
1,600
ppm
4,455
2,284
686
­
26%
11%
3%
0%
GE
2,000
ppm
3,929
2,194
686
­
23%
11%
3%
0%
GE
5,000
ppm
1,891
865
231
­
11%
4%
1%
0%
Missingd
145
­
190
­
1%
0%
1%
0%
No
soil
1,003
939
95
205
6%
5%
0%
1%
Total
17,476
20,544
27,893
29,774
100%
100%
100%
100%

a
"
Housing
units"
include
permanently
occupied,
noninstitutional
housing
units
in
which
children
are
permitted
to
live.
b
All
percentages
are
calculated
with
total
housing
units
of
that
age
as
the
common
denominator.
c
GE
equals
"
greater
than
or
equal
to."
d
"
Missing"
means
that
soil
was
present,
but
that
no
lead
value
is
available
(
usually
due
to
inaccessibility
or
respondent
refusal).
"
No
soil"
means
that
there
was
no
soil
on
the
property
to
sample.
APPENDIX
B
Comparison
of
Protocols
for
the
HUD
1990
Survey
of
Lead­
Based
Paint
(
LBP)
in
Housing
and
the
HUD
National
Survey
of
Lead
and
Allergens
in
Housing
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
B­
2
October
31,
2002
Comparison
of
Protocols
for
the
HUD
1990
Survey
of
Lead­
Based
Paint
(
LBP)
in
Housing
and
the
HUD
National
Survey
of
Lead
and
Allergens
in
Housing
Area
HUD
National
Survey
of
Lead­
Based
Paint
in
Housing
HUD
National
Survey
of
Lead
and
Allergens
in
Housing
Types/
numbers
of
housing
units
selected
for
the
survey
and
whose
data
were
available
to
the
TSCA
Section
403
risk
analysis
284
housing
units
selected
from
occupied,
permanent,
non­
institutional
housing
in
the
48
coterminous
states
built
prior
to
1980
and
having
the
potential
for
containing
children.
(
These
units
were
all
privately­
owned.
While
publicly­
owned
units
were
also
selected
for
the
survey,
data
for
these
units
are
not
considered
in
this
summary.)
831
housing
units
selected
in
a
threestage
stratified
random
sample
from
occupied,
permanent,
noninstitutionalized
housing
having
the
potential
for
containing
children.
75
primary
sampling
units
(
PSUs).

Breakdown
of
selected
units
by
year
built
Pre­
1940:
27%
1940­
1959:
31%
1960­
1979:
42%
Post­
1979:
0%
Pre­
1940:
18%
1940­
1959:
22%
1960­
1977:
29%
Post­
1977:
31%

Dates
of
environmental
sampling
November
1989
to
March
1990
August
1998
to
February
1999,
and
from
July
to
August
1999
Selecting
rooms
for
environmental
sampling
Telephone
household
interview
provided
information
on
rooms.
One
room
was
selected
for
sampling
in
each
of
the
following
strata:


Wet
room
­­
rooms
containing
plumbing
(
e.
g.,
kitchen,
bathroom,
laundry
room,
utility
room)


Dry
room
­­
all
rooms
not
classified
as
wet
rooms

Main
entryway
(
floor
dust
samples
only)
Room
Inventory
Form
from
the
Screening/
Recruiting
Questionnaire
was
used
to
obtain
information
on
rooms.
One
room
was
randomly
selected
for
sampling
in
each
of
the
following
four
strata:


Kitchen

Common
living
area
(
e.
g.,
living
room,
den,
family
room)


Bedroom
in
which
one
or
more
children
aged
17
years
or
younger
regularly
slept,
or
any
regularlyoccupied
bedroom
if
no
such
children
lived
in
the
unit
(
occasionally,
two
such
bedrooms
were
selected)


Other
random
room
among
the
remaining
rooms
in
the
housing
unit.
(
Note:
Two
rooms
were
randomly
selected
from
this
stratum
if
the
stratum
contained
at
least
six
rooms.)


Main
entry
(
floor
dust
only)


Interior
common
area
(
multi­
family
dwellings,
floor
dust
only)

Method
of
assigning
sampling
weights
Weights
reflect
the
various
stages
of
sampling.
Total
of
the
sampling
weights
Weights
reflect
the
various
stages
of
sampling.
Total
of
the
sampling
weights
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
B­
3
October
31,
2002
Area
HUD
National
Survey
of
Lead­
Based
Paint
in
Housing
HUD
National
Survey
of
Lead
and
Allergens
in
Housing
equaled
the
estimated
number
of
housing
units
with
children
under
age
7
years
(
13,912,000,
as
estimated
by
the
1987
AHS).
Total
of
the
sampling
weights
within
a
given
census
region
equaled
the
estimated
number
of
units
with
children
under
age
7
years
in
the
census
region.
within
a
given
census
region
equals
the
estimated
number
of
units
in
the
census
region.

Method
for
taking
dust
samples
for
lead
analysis
Blue
Nozzle
vacuum
(
a
few
wipe
samples
were
also
collected).
Sampling
house
dust
for
lead:
basic
concepts
and
literature
review.
(
1995).
EPA
747­
R­
95­
007.
Wipes,
collected
in
accordance
with
ASTM
E1728­
95,
Practice
for
the
field
determination
of
settled
dust
samples
using
wipe
sampling
methods
for
lead
determination
by
atomic
absorption
spectrometry
techniques.

Number
and
location
of
floor­
dust
samples
per
room
One
sample
from
each
selected
room
(
location
not
dictated
in
the
protocol)
One
sample
from
each
selected
room,
generally
taken
from
the
center
of
the
largest
open
area
of
the
room.

Window
sill/
trough
dust
sampling
approach
A
window
was
selected
within
each
selected
room
according
to
a
ranking
scheme.
Sampling
was
performed
from
both
the
sill
and
trough
of
the
selected
window
until
enough
dust
was
collected
or
until
the
entire
sill
or
trough
was
vacuumed.
Entire
sill
and
trough
sampled
from
a
random
window
in
the
selected
room.
Trough
definition
included
sliders.

Number
and
location
of
sill
and
trough
dust
samples
per
room
One
sample
from
the
sill
and
one
sample
from
the
trough
of
the
selected
window
in
the
selected
wet
room
and
dry
room
One
sample
from
the
sill
and
one
sample
from
the
trough
of
the
selected
window
in
each
selected
room
Method
of
analyzing
dust
samples
Graphite
Furnace
Atomic
Absorption
Spectroscopy
(
GFAA)
(
with
EPA
SW­
846
digestion
method)
Flame
Atomic
Absorption
Spectrometry
(
FAAS)
using
NIOSH
method
7082
Digestion
method:
modification
of
EPA
SW­
846
Method
3050
or
ASTM
ES
36­
94
(
hot­
plate
digestions
utilizing
nitric
acid
and/
or
perchloric
acid
and/
or
hydrogen
peroxide).
Method
same
as
used
in
proficiency
testing
within
the
Environmental
Lead
Laboratory
Accreditation
Program
(
ELLAP).

Soil
sampling
approach
One
composite
sample
of
up
to
3
core
samples
(
the
latter
two
taken
within
20
inches
of
the
first),
each
taken
at
a
depth
of
10
cm,
was
collected
at
each
of
the
following
locations:
entryway,
drip­
line,
and
remote
area
(
i.
e.,
an
area
halfway
between
the
unit
and
its
property
boundary,
or
within
25
feet
of
the
unit,
whichever
was
less).
Two
sides
of
the
unit
were
selected
for
soil
sampling:
the
side
containing
the
major
entryway
(
Wall
1)
and
a
second,
randomly­
selected
side
(
Wall
2).
Samples
were
collected
from
the
top
0.5
inches
of
soil
at
the
following
three
sites:


Main
entry
­
a
single
sample
from
Wall
1
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
B­
4
October
31,
2002
Area
HUD
National
Survey
of
Lead­
Based
Paint
in
Housing
HUD
National
Survey
of
Lead
and
Allergens
in
Housing

Foundation/
drip­
line
­
one
sample
from
each
of
Walls
1
and
2,
each
sample
being
a
composite
of
3
core
subsamples
taken
within
3
feet
of
the
foundation

Mid­
yard
area
­
one
sample
from
each
of
Walls
1
and
2,
each
sample
being
a
composite
of
3
core
subsamples
taken
midway
between
the
drip­
line
and
boundary
of
the
housing
unit
property.


Play
Area
 
one
composite
sample
from
bare
soil
under
each
unit
of
fixed
play
equipment.

Soil
samples
were
collected
in
accordance
with
core
sampling
procedures
based
on
ASTM
E1727­
95
(
described
in
the
HUD
Guidelines
and
in
EPA's
Residential
Sampling
for
Lead:
Protocols
for
Leaded
Dust
and
Soil
Sampling).
Samples
were
collected
from
bare
soil
when
possible.
If
no
bare
soil
existed,
samples
were
collected
from
covered
surfaces
if
possible.

Method
of
analyzing
soil
samples
ICP­
AES
(
with
SW­
846
digestion
method)
ICP­
AES
using
NIOSH
method
7082
Digestion
method:
modification
of
SW­
846
Method
3050
or
ASTM
ES
36­
94
(
hot­
plate
digestions
utilizing
nitric
acid
and/
or
perchloric
acid).
Method
same
as
used
in
proficiency
testing
within
the
Environmental
Lead
Laboratory
Accreditation
Program
(
ELLAP).

Handling
dust­
lead
and
soil­
lead
measurements
below
the
detection
limit
As
log­
transformed
lead
amounts
are
reported
in
the
database,
only
positive
measurements
are
represented.
No
indication
is
given
as
to
when
data
may
have
been
truncated
due
to
being
below
detection
limits.
The
final
results
as
reported
by
the
instrument
are
recorded
in
the
database
(
i.
e.,
not­
detected
results
are
not
censored),
along
with
detection
limits.

Method
for
taking
paintlead
measurements
Spectrum
analyzer
XRF
instrument
(
single
60­
second
spectrum
reading
measurement
using
a
40
millicurie
cobalt
source).
Measurements
were
adjusted
to
statistically
correct
for
measurement
bias.
Spectrum
analyzer
XRF
analyzer
(
fullperiod
readings
with
a
20­
second
minimum
in
accordance
with
the
applicable
HUD­
approved
Performance
Characteristic
Sheet
.)

Approach
to
selecting
interior
painted
Painted
surfaces
were
categorized
into
the
following
four
strata:
The
following
painted
components
were
measured
for
lead
in
each
selected
room:
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
B­
5
October
31,
2002
Area
HUD
National
Survey
of
Lead­
Based
Paint
in
Housing
HUD
National
Survey
of
Lead
and
Allergens
in
Housing
components
for
paint­
lead
measurements

Walls/
ceilings/
floors

Metal
substrate

Non­
metal
substrate

Other
surfaces
Five
painted
components
were
selected
randomly
for
testing
in
each
of
the
selected
wet
and
dry
rooms,
one
from
each
stratum
along
with
a
fifth
selected
randomly
from
among
all
strata.
In
addition,
up
to
two
purposive
measurements
were
taken
from
paint
anywhere
in
the
unit
that
may
be
suspected
to
contain
lead.

All
four
major
walls

Ceiling

Door
of
major
entryway

Window
selected
for
dust
sampling

Baseboard

Floor

Up
to
two
other
painted
surfaces:
Technician
choice
based
on
surfaces
containing
deteriorated
paint
or
friction
areas.

Approach
to
selecting
exterior
painted
components
for
paint­
lead
measurements
Painted
surfaces
were
categorized
into
the
following
four
strata:


Wall
(
randomly­
selected)


Metal
substrate
within
the
selected
wall

Non­
metal
substrate
within
the
selected
wall

Other
surfaces
within
the
selected
wall
Five
painted
components
were
selected
randomly
for
testing
from
the
side
of
the
unit
containing
the
selected
wall,
one
from
each
stratum
along
with
a
fifth
selected
randomly
from
among
all
strata.
In
addition,
up
to
two
purposive
measurements
were
taken
from
paint
anywhere
on
the
exterior
of
the
unit
that
may
be
suspected
to
contain
lead.
Painted
siding
was
measured
for
lead
levels
on
each
exterior
wall.
In
addition,
the
following
painted
components
were
measured
for
lead
on
a
random
wall:


Miscellaneous
trim
(
2
measurements)


Window

Door
of
major
entryway
 
wall
independent.


Porch
and
railing
 
wall
independent

Up
to
two
other
painted
surfaces
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
1
October
31,
2002
APPENDIX
C
Correcting
for
Classification
Bias
Due
to
Measurement
Error
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
2
October
31,
2002
CORRECTING
FOR
CLASSIFICATION
BIAS
DUE
TO
MEASUREMENT
ERROR
Homes
were
classified
as
having
LBP
and
lead
hazards
based
on
the
XRF
readings
of
paint
and
the
analysis
of
dust
and
soil
samples.
Random
variation
associated
with
instrument
or
laboratory
measurement,
sample
collection,
and
random
selection
of
sampling
locations,
can
induce
a
classification
bias
resulting
in
a
bias
in
the
estimated
prevalence
of
HUs
with
LBP
and
lead
hazards.
In
addition,
paint
and
dust
measurements
were
made
in
a
sample
of
rooms
 
not
all
rooms.
Under
this
protocol,
it
is
possible
for
a
home
to
have
LBP
or
a
LBP
dust
hazard
in
the
unsampled
rooms
and
non­
lead­
based
paint
and/
or
no
dust­
lead
hazard
in
the
sampled
rooms.
Such
HUs
would
be
incorrectly
classified
as
not
having
LBP
and/
or
LBP
hazards
(
false
negatives).
For
this
report,
measurement
error
refers
to
the
combined
effect
of
instrument
or
laboratory
measurement
variation,
sampling
variation,
spatial
variation,
and
the
incomplete
sampling
of
rooms
on
the
important
survey
estimates.

The
specific
procedures,
equations,
and
justification
for
the
measurement
error
correction
are
presented
in
Appendix
C
of
Volume
II.
The
findings
for
the
measurement
error
analyses
for
paint,
dust,

and
soil
are
discussed
below
in
Sections
7.3.1
through
7.3.3
below.
The
measurement
error
adjusted
values
(
lead
loading
or
concentration)
have,
to
the
extent
possible,
the
same
distribution
as
the
true
lead
loading
or
lead
concentration
values,
without
the
effect
of
measurement
error.
The
measurement
error
corrected
values
are
a
weighted
average
of
the
observed
measurements
and
predicted
values
from
a
regression
model.
Calculating
the
weights
requires
modeling
the
magnitude
of
the
measurement
error
variance
and
the
regression
error
variance.
Replicate
measurements
were
used
to
estimate
the
measurement
error
variance.

Note
that
this
analysis
used
preliminary
data
from
the
main
survey.
The
analysis
did
not
include
data
from
the
follow­
on
play
area
survey.
In
addition,
minor
revisions
or
corrections
to
the
data
may
have
been
made
since
the
analysis
was
performed.
As
a
result,
summary
statistics
from
the
measurement
error
analysis
may
not
agree
with
those
in
other
sections
of
the
report.
Nevertheless,
the
effects
of
measurement
error
are
expected
to
similar
in
the
preliminary
and
final
data.

C.
1
Measurement
Error
­
Paint
XRF
Measurements
XRF
readings
to
measure
paint
lead
loading
were
taken
on
painted
surfaces
within
the
sampled
rooms
and
on
accessible
exterior
surfaces
on
two
sides
of
the
building
to
assess
the
lead
loading
in
paint.
The
measurement
error
adjustment
procedures
were
first
applied
to
the
interior
XRF
readings.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
3
October
31,
2002
Because
the
measurement
error
adjusted
XRF
values
were
very
close
to
the
original
interior
XRF
readings,

it
was
considered
unnecessary
to
apply
a
measurement
error
adjustment
to
the
exterior
XRF
readings.

For
the
measurement
error
analysis
for
paint
lead
measurements,
the
objective
was
to
determine
the
number
and
percentage
of
homes
with
LBP.
A
surface
with
LBP
is
a
surface
with
an
average
lead
loading
across
the
surface
of
1.0
mg/
cm2
or
greater
when
tested
with
an
XRF
analyzer.
The
instrument
calculates
its
best
internal
estimate
of
the
lead
loading,
which
it
rounds
to
the
nearest
0.1
mg/
cm2
for
display.
Therefore,
to
classify
surfaces
in
an
equivalent
manner,
the
error
corrected
XRF
readings
were
rounded
to
the
nearest
tenth
unit
for
classifying
surfaces.
60
The
classification
of
surfaces
as
having
or
not
having
LBP
is
used
to
classify
homes
as
having
or
not
having
LBP.

The
measurement
error
adjustment
procedure
assumes
that
the
distribution
of
the
true
paint
lead
loading
around
the
average
for
similar
homes
and
the
distribution
of
the
measurement
error
are
normal.
This
assumption
provided
a
relatively
poor
description
of
the
XRF
readings
due
to
the
presence
of
many
zero
XRF
readings
and
long
tails
in
the
XRF
distribution
(
the
measurement
error
adjustment
results
are
expected
to
be
sensitive
values
in
the
tails
of
the
distribution).
As
a
result,
the
measurement
error
adjustment
for
paint
lead
loadings
should
be
considered
approximate,
at
best.
Additional
research
into
the
measurement
error
of
the
XRF
instrument
and
the
distribution
of
paint
lead
loading
across
components
would
be
required
to
improve
the
measurement
error
adjusted
values.

Figure
C.
1,
which
shows
a
scatter
plot
of
replicate
XRF
readings,
helps
to
illustrate
the
distribution
of
the
XRF
readings.
The
original
XRF
reading
is
on
the
horizontal
axis
and
the
replicate
reading
is
on
the
vertical
axis.
Three
situations
occur.
The
first
is
where
both
XRF
readings
are
zero
(
72.3
percent
of
the
replicate
pairs)
­
these
pairs
provide
essentially
no
information
about
measurement
error.

The
second
case
is
where
one
of
the
two
readings
is
zero
(
12.4
percent
of
the
replicate
pairs)
­
these
pairs
fall
on
the
axes.
Lastly,
there
is
the
case
where
both
XRF
readings
are
non­
zero
(
15.3
percent
of
the
replicate
pairs)
 
these
generally
fall
on
the
diagonal
in
Figure
C.
1.
For
these
points,
the
differences
between
the
replicate
XRF
readings
have
an
approximately
normal
distribution
as
assumed
by
the
measurement
error
correction
procedure.

The
XRF
variation
among
all
surfaces
within
a
home
increases
with
the
average
XRF
reading
within
the
home.
This
suggests
that
the
measurement
error
will
also
increase
with
the
paint
lead
loading
on
60
Rounding
to
the
nearest
tenth
unit
for
classifying
surfaces
is
equivalent
to
classifying
a
surfaces
as
having
LBP
if
the
average
lead
loading
across
the
surface
is
0.95
or
greater.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
4
October
31,
2002
a
component.
Surfaces
with
lead
loading
near
zero
will
have
relatively
precise
measurements
and
we
expect
that
large
differences
between
replicate
readings
when
one
reading
is
zero
will
be
relatively
rare.

However,
there
are
many
surfaces
for
which
one
reading
is
zero
and
the
other
paired
reading
is
relatively
large
(
may
be
due
to
two
different
parts
of
a
component
having
very
different
paint
lead
loadings).
61
Figure
C.
1
Original
and
Replicate
XRF
Readings
on
the
Same
Component
50
40
30
20
15
10
9
8
7
6
5
4
3
2
1
0
­
1
­
2
50
40
30
20
15
10
98
7
6
5
4
3
2
1
0
­
1
­
2
Original
XRF
Reading
Replicate
XRF
Reading
Note:
The
axes
use
the
transformed
scale
used
for
analysis
(
see
Equation
9
in
Appendix
C,
Volume
II).

For
the
measurement
error
adjustment,
homes
in
which
all
XRF
readings
were
zero
or
negative
(
162
HUs)
were
assumed
to
have
no
paint
lead.
The
remaining
homes
were
used
in
the
61
Whatever
the
explanation
for
the
pattern
in
the
data,
the
patterns
are
not
consistent
with
the
assumptions
behind
the
measurement
error
adjustment.
Since
no
consistent
pattern
was
found
that
would
provide
a
better
model,
the
measurement
error
adjustment
as
described
in
Appendix
C
(
Volume
II)
was
applied
to
the
data.
The
results
provide
one
estimate
of
the
effect
of
measurement
error
on
the
assessment
of
the
number
of
homes
with
LBP.
However,
other
assumptions
or
other
modeling
approaches
may
provide
very
different
estimates
of
the
magnitude
of
the
effect
of
measurement
error.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
5
October
31,
2002
measurement
error
analysis.
For
those
homes,
the
model
used
to
predict
paint
lead
loadings
had
factors
for
housing
unit
ID,
room
type,
year
of
construction,
and
interactions
of
year
of
construction
by
substrate,

component,
and
percent
deteriorated
paint.
A
preliminary
analysis
suggested
that
the
relationship
between
paint
deterioration
and
XRF
reading
was
not
linear.
To
make
the
relationship
closer
to
linear,
the
cube
of
the
percent
deterioration
was
used
in
the
model.
A
further
analysis
of
the
relationship
would
be
necessary
to
provide
a
better
model.

The
regression
analysis
predicts
the
approximate
median
of
the
interior
paint
lead
loading.

Figure
C.
2
shows
the
relative
median
paint
lead
loading
estimated
from
regression,
by
construction
year
category
and
component
substrate.
Figure
C.
3
shows
the
relative
differences
in
median
paint
lead
loading
associated
with
combinations
of
construction
year
and
region
of
the
country.
Figure
C.
4
and
7.5
shows
the
relative
differences
in
the
median
paint
lead
loading
versus
component
type,
room
type,
component
condition,
metro
status,
presence
of
pets,
overall
home
cleanliness,
and
the
number
of
days
the
air
conditioning
was
used
in
the
last
month.
Because
the
assumptions
behind
the
measurement
error
analysis
provide
a
poor
description
of
the
XRF
measurements,
the
patterns
illustrated
in
Figures
7.2
to
7.5
should
be
considered
suggestive
of,
rather
than
descriptive
of,
patterns
in
the
population.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
6
October
31,
2002
Figure
C.
2
Predicted
Relative
Median
Paint
Lead
Loading
by
Construction
Year
of
the
Home
and
Substrate
(
based
on
regression
model)

0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
1750­
1939
1940­
1959
1960­
1977
1978­
1998
Relative
Median
Paint
Lead
Loading,
mg/
cm2
(
See
text)

Drywall
Metal
Other
Paneling
Plaster
Wallpaper
Wood
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
7
October
31,
2002
Figure
C.
2
shows
that
interior
paint
lead
loadings
are
highest
in
the
oldest
homes
and
lowest
in
the
newest
homes.
The
patterns
for
paint
lead
loading
on
specific
substrates
also
generally
decrease
with
the
age
of
the
home.
The
paint
lead
loadings
are
highest
on
wood
surfaces
in
the
oldest
homes.
For
components
with
drywall,
paneling,
metal,
plaster,
wallpaper,
and
wood
substrates,
the
median
paint
lead
loading
is
low
(
less
than
0.05
mg/
cm2)
for
homes
built
since
1960.
However,
median
paint
lead
loading
on
other
substrates
(
such
as
brick,
concrete,
stone,
and
vinyl)
are
higher
for
homes
built
in
the
1960
to
1977
period.

Figure
C.
3
shows
that
the
highest
predicted
median
paint
lead
loading
is
found
in
homes
built
before
1960
in
the
northeast
US
and
in
homes
built
before
1940
in
the
southern
US.
62
Figure
C.
3
Predicted
Relative
Median
Paint
Lead
Loading
by
Construction
Year
of
the
Home
and
Region
(
based
on
regression
model)

0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
1750­
1939
1940­
1959
1960­
1977
1978­
1998
Year
of
Construction
Relative
Median
Paint
Lead
Loading,
mg/
cm2
(
See
text)

Midwest
Northeast
South
West
62
Care
should
be
taken
when
comparing
these
data
to
tables
presented
in
Chapter
4.
For
example,
a
home
was
included
in
Table
4.1
if
any
one
component
had
LBP.
Values
plotted
in
Figures
7.2
through
7.5
represent
the
predicted
median
paint
loadings
in
the
home
(
i.
e.,
for
all
components).
Thus,
while
Table
4.1
shows
that
53%
of
homes
in
the
Midwest
have
LBP,
Figure
C.
3
shows
that
the
median
lead
loading
for
all
components
is
lowest
for
homes
in
the
Midwest.
This
could
be
due
to
there
being
fewer
components
with
LBP
or
the
lead
content
of
individual
components
could
be
lower
in
Midwest
homes.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
8
October
31,
2002
Figure
C.
4
shows
that
higher
paint
lead
loadings
are
generally
found
on
doors,
window
jambs
and
window
sashes.
There
are
relatively
small
but
significant
differences
in
the
paint
lead
loading
among
rooms
of
different
types.
After
accounting
for
other
factors,
paint
lead
loadings
are
generally
higher
in
children's
bedrooms
and
in
kitchens.

Figure
C.
4
Predicted
Relative
Median
Paint
Lead
Loading
by
Component
Type
and
Room
Type
(
based
on
regression
model)

0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Baseboard
Ceiling
Door
jamb
Entry
door
Miscelaneous
Wall
Window
apron
Window
jamb
Window
sash
Window
sill
Adult
bedroom
Bathroom
Child
bedroom
Kitchen
Living
room
Other
Relative
Median
Paint
Lead
Loading,
mg/
cm2
(
See
text)

Component
Room
type
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
9
October
31,
2002
Figure
C.
5
shows
that
higher
paint
lead
loadings
are
generally
found
on
components
that
were
judged
to
be
in
fair
condition
as
opposed
to
intact
or
poor
condition.
However,
relatively
few
surfaces
were
judged
to
be
in
fair
condition.
Small
but
significant
differences
were
associated
with
metro
status
(
lower
paint
lead
loading
in
non­
MSAs),
presence
of
pets
(
lower
in
homes
with
pets),
overall
cleanliness,
and
days
using
air
conditioning
in
the
last
month.

Figure
C.
5
Predicted
Relative
Median
Paint
Lead
Loading
by
Component
Condition,
Metro
Status,
Presence
of
Pets,
Overall
Cleanliness,
and
Air
Condition
Use
in
the
Last
Month
(
based
on
regression
model)

0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Intact
Fair
Poor
Missng
MSA>
1M
MSA<
1M
nonMSA
Pets
No
pets
Appears
clean
Some
cleaning
No
cleaning
Unknown
zero
1
to
9
10
to
19
20
to
30
31
days
Relative
Median
Paint
Lead
Loading,
mg/
cm2
(
See
text)

Component
condition
Metro
status
Currently
pets
Cleanliness
Days
using
AC
in
last
month
As
part
of
the
exploratory
analysis
to
identify
the
model
for
the
data,
such
additional
variables
as
tenure
and
race
were
considered
and
not
found
to
be
significant
predictors.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
10
October
31,
2002
The
measurement
error
adjustment
procedure
identified
approximately
30
percent
of
the
XRF
readings
as
outliers.
Outliers
are
those
measurements
that
are
more
than
2.5
standard
deviations
above
or
below
the
mean
of
the
non­
outliers.
In
this
case,
the
measurement
error
procedure
makes
a
conservative
adjustment.
The
non­
outlier
data
were
assumed
to
have
a
normal
error
distribution,
however,
the
distribution
of
the
residuals
had
a
tight
distribution
in
the
center
and
very
long
tails,
inconsistent
with
the
normal
distribution
assumption.
The
resulting
estimate
of
the
error
variance
was
very
small,
resulting
in
almost
no
estimated
effect
of
measurement
error.
Using
the
measurement
error
procedure
in
Appendix
C
(
Volume
II),
the
measurement
error
adjusted
paint
lead
loadings
are
essentially
equal
to
the
XRF
readings.

Additional
work
would
be
required
to
develop
a
better
model
for
the
XRF
readings
and
other
assumptions
might
provide
a
significantly
different
assessment
of
the
effects
of
measurement
error.

The
tentative
results
from
the
measurement
error
analysis
are
that
the
interior
XRF
readings
provide
a
reasonable
measure
of
the
paint
lead
loading
for
many
surfaces.
For
the
remaining
surfaces
that
look
like
outliers
when
judged
relative
to
a
normal
distribution,
the
effect
of
measurement
error
is
difficult
to
assess.
We
believe
that
similar
conclusions
are
likely
to
apply
to
exterior
surfaces;
however,
no
measurement
error
adjustment
was
attempted
for
the
exterior
surfaces.

C.
2
Measurement
Error
 
Dust
Lead
Measurements
Dust
samples
were
taken
at
all
surveyed
homes
from
the
floor
at
the
main
entrance
and
from
the
floors,
window
sills,
and
window
troughs
of
the
sampled
rooms.
Separate
measurement
error
adjustments
were
performed
for
the
floor
and
window
dust
samples.

Floor
Dust
Lead
Loading
The
model
for
predicting
floor
dust
lead
loading
included
factors
for
household
ID
(
as
a
class
variable),
surface
characteristics
at
the
sample
location,
and
the
interaction
of
the
type
of
floor
cover
and
year
of
construction.
The
measurement
error
adjustment
procedures
excluded
three
percent
of
the
floor
dust
measurements
as
outliers.
The
regression
analysis
predicts
the
approximate
median
of
the
floor
dust
lead
loading.

Figure
C.
6
shows
the
relative
median
floor
dust
lead
loading
estimated
from
regression,
by
construction
year
category
and
type
of
floor
cover
in
the
sampled
room.
The
predicted
median
floor
dust
lead
loadings
were
highest
for
the
oldest
homes
and
decrease
for
homes
constructed
more
recently.
The
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
11
October
31,
2002
floor
lead
loading
was
generally
higher
in
rooms
with
no
floor
covering
than
in
rooms
with
wall­
to­
wall
carpets.
Rooms
with
some
floor
covering
had
floor
dust
loadings
similar
to
or
somewhat
greater
than
in
rooms
with
wall­
to­
wall
carpets,
and
lower
than
rooms
with
no
floor
covering.
The
floor
lead
loadings
for
the
unknown
floor
cover
category
represent
primarily
the
floor
dust
lead
loadings
for
the
main
entrance
(
94%
of
the
data
in
the
unknown
category,
as
this
information
was
not
recorded).
The
dust
lead
loading
at
the
main
entrance
was
similar
to
dust
lead
loading
from
other
rooms
that
have
no
floor
covering.

Figure
C.
6
Predicted
Relative
Median
Floor
Dust
Lead
Loadings
by
Construction
Year
Category
and
Floor
Cover
in
the
Sampled
Room
(
based
on
regression
model)

0
1
2
3
4
5
6
7
1750­
1939
1940­
1959
1960­
1977
1978­
1998
Construction
Year
Category
Relative
Median
Floor
Lead
Loading,
µ
g/
ft2
(
see
text)

No
floor
cover
Some
floor
cover
(
area
rug,
mat,
etc.)
Wall­
to­
wall
carpet
Unknown
(
primarily
main
entrance
samples)
Floor
cover
in
sampled
room
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
12
October
31,
2002
Figure
C.
7
shows
the
relative
median
floor
dust
lead
loading
estimated
from
regression,
by
home
cleanliness,
household
income,
and
surface
sampled.
Dust
lead
loadings
were
on
average
higher
in
lower
income
homes,
and
in
homes
that
show
no
evidence
of
cleaning
(
a
small
minority
of
all
homes).
63
Dust
lead
loadings
were
also
higher
on
hard
surfaces
that
were
not
smooth
and
cleanable
(
a
small
minority
of
all
surfaces),
perhaps
because
these
surfaces
are
more
difficult
to
clean
or
perhaps
because
they
collect
dust
faster
between
cleanings.
Carpets
had
lower
lead
loading
than
smooth
and
cleanable
surfaces,
using
the
wipe
sampling
methods
employed.

Figure
C.
7
Predicted
Relative
Median
Floor
Dust
Lead
Loadings
by
Cleanliness,
Household
Income,
and
Surface
Condition
(
based
on
regression
model)

0
1
2
3
4
5
6
7
Appears
clean
Some
evidence
of
cleaning
No
evidence
of
cleaning
Unknown
up
to
30K
30K
or
over
Carpeted
Smooth
and
cleanable
Hard
but
not
smooth/
cleanable
Unknown
Relative
Median
Dust
Lead
Loading,
µ
g/
ft
2
(
see
text)

Overall
Household
Cleanliness
Household
Income
Surface
Condition
at
Sample
Location
63
These
results
suggest
that
cleaning
activity
will
generally
affect
dust
lead
loading.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
13
October
31,
2002
As
part
of
the
exploratory
analysis
to
identify
the
model
for
the
data,
additional
variables
were
considered
and
not
found
to
be
significant
predictors.
In
particular,
the
type
of
room
(
bedroom,
bathroom,

kitchen,
etc.)
and
presence
of
pets
were
not
significant.

Figure
C.
8
shows
the
cumulative
distribution
of
the
maximum
floor
dust
lead
loading
at
homes.
The
figure
shows
three
cumulative
distributions:

1.
The
maximum
of
the
floor
dust
lead
loading
measurements
at
a
home
(
bottom
thin
black
line).

2.
The
maximum
measurement
error
adjusted
floor
dust
lead
loading
across
the
sampled
rooms
(
top
gray
line).

3.
The
maximum
measurement
error
adjusted
floor
dust
lead
loading
across
all
rooms,
sampled
and
unsampled
(
middle
thick
black
line).

The
difference
between
the
first
(
bottom
thin
black)
and
second
(
top
gray)
curves
shows
the
effect
of
the
measurement
error
adjustment
on
the
classification
of
the
measured
surfaces.
The
difference
between
the
second
(
top
gray)
and
the
third
(
middle
thick
black)
curves
illustrates
the
effect
of
random
selection
of
rooms
on
the
classification
of
homes.
Measurement
error
tends
to
increase
the
number
of
homes,
and
incomplete
sampling
of
rooms
tends
to
decrease
the
number
of
homes,
classified
as
having
maximum
floor
dust
lead
loading
above
a
selected
value.
For
the
floor
data,
these
effects
partially
cancel
out
so
that
the
number
of
homes
classified
as
having
floor
lead
over
a
specified
value
using
either
the
maximum
adjusted
lead
loading
value
or
the
maximum
observed
measurements
is
similar.
The
difference
between
the
first
(
bottom
thin
black)
and
the
third
(
middle
thick
black)
curves
illustrates
the
combined
effect
of
doing
both
the
measurement­
error
adjustment
and
unsampled­
room
adjustment.

Using
the
measurement
error
corrected
values,
an
estimated
four
percent
of
homes
(
about
4
million
homes)
have
floor
dust
lead
loadings
of
40
µ
g/
ft2
or
more
in
one
or
more
rooms.
This
is
about
one
percent
fewer
homes
than
estimated
using
the
actual
floor
dust
measurements.

Figure
C.
8
Cumulative
Distribution
of
the
Maximum
Floor
Dust
Lead
Loading
for
Homes
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
14
October
31,
2002
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%

1
10
100
1000
Floor
dust
lead
loading
(
µ
g/
ft2)
Percent
of
homes
with
lower
floor
dust
lead
loadings
Measurements
Adjusted
for
measurement
error
Adjusted
for
unsampled
rooms
Window
Dust
Lead
Loading
Window
dust
samples
were
taken
from
randomly
selected
windows
in
the
sampled
rooms
within
surveyed
homes.
For
the
measurement
error
correction,
one
objective
was
to
estimate
the
number
of
rooms
having
or
not
having
average
window
sill
dust
lead
loading
and
average
window
trough
dust
lead
loading
less
than
a
selected
value.
A
second
objective
was
to
estimate
the
number
of
homes
with
average
room
window
sill
and
window
trough
dust
lead
loading
less
than
a
selected
value
in
all
rooms.
The
first
objective
required
estimating
lead
loadings
for
the
missing
values
and
adjusting
for
measurement
error.

The
second
objective
also
required
adjusting
for
the
unknown
lead
loading
in
the
unsampled
rooms.

Scatter
plots
of
the
data
showed
that
the
log
transformed
window
sill
and
trough
measurements
are
linearly
related,
with
the
ratio
of
the
trough
to
sill
lead
loading
being
roughly
constant
at
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
15
October
31,
2002
about
11.
The
proximity
of
the
sill
to
the
trough
suggests
that
the
similar
factors
may
affect
the
lead
loading
at
these
two
locations.
Therefore,
the
analysis
below
used
both
the
window
sill
and
window
trough
dust
lead
loadings
in
the
same
model
for
calculating
the
measurement
error
adjustment.
Because
the
log
transformation
was
used,
the
model
assumes
that
the
same
factors
predict
the
relative
sill
and
trough
lead
loadings
and
that
the
ratio
of
the
sill
to
trough
lead
loading
was
constant
across
homes.
Although
a
separate
measurement
error
adjustment
could
have
been
performed
separately
for
sill
and
trough
measurements,
this
combined
approach
was
expected
to
provide
a
similar
adjustment.
The
measurement
error
adjustment
procedures
excluded
three
percent
of
the
floor
dust
measurements
as
outliers.

Two
models
were
fit
to
the
data.
One
was
used
for
predicting
window
dust
lead
loading
in
homes
with
at
least
one
window
lead
loading
measurement.
A
second
model
was
used
to
predict
window
dust
lead
loading
for
homes
with
no
window
dust
lead
loading
measurements
in
the
data
files.
The
predictors
in
each
model
are
presented
in
Table
C.
1.

Table
C.
1
Regression
Model
Used
for
Different
Categories
of
Homes
Category
of
homes
Number
of
homes
Factors
for
predicting
window
dust
lead
loading
I.
Homes
with
no
window
dust
samples
17
Sample
location
(
sill
or
trough),
year
of
construction,
tenure,
race
category
of
occupants,
overall
household
cleanliness
as
judged
by
the
interviewer,
and
room
type.

II.
Homes
with
at
least
one
window
dust
sample
808
Sample
location
(
sill
or
trough),
household
ID
(
as
a
class
variable),
surface
characteristics
at
the
sample
location,
whether
the
window
has
a
vinyl
mini­
blind,
and
room
type.

Figure
C.
9
shows
the
relative
differences
in
median
window
dust
lead
loading
associated
with
different
levels
of
sample
location
(
sill
or
trough),
year
of
construction,
tenure,
race
category,
overall
household
cleanliness,
surface
characteristics,
room
type,
and
presence
of
vinyl
mini­
blinds.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
16
October
31,
2002
Figure
C.
9
Predicted
Median
Window
Dust
Lead
Loading
by
Various
Factors
(
based
on
regression
model)

0
200
400
600
800
1000
1200
Some
evidence
of
cleaning
Window
sill
Window
trough
1750­
1939
1940­
1959
1960­
1977
1978­
1998
Privately
owned
Publically
owned
Rented
African
American
Other/
Unknown
White
Appears
clean
No
evidence
of
cleaning
Unknown
Adult
bedroom
Bathroom
Child
bedroom
Kitchen
Living
room
Other
Unknown
Smooth
and
cleanable
Not
smooth/
cleanable
No
vinyl
mini­
blinds
Vinyl
mini­
blinds
Unknown
Relative
Median
Dust
Lead
Loading,
µ
g/
ft
2
(
see
text)

Sample
location
Construction
date
Tenure
Race
category
Overall
Household
Cleanliness
Room
type
Sample
surface
Vinyl
miniblinds
The
predicted
median
window
dust
lead
loading
is
much
higher
in
the
window
trough
than
on
the
window
sill.
Lead
loading
is
highest
for
the
oldest
homes
and
lower
for
homes
constructed
more
recently.
The
window
lead
loading
is
generally
higher
for
rented
homes
than
in
private
owned
homes
and
higher
in
homes
with
African
American
residents
and
in
homes
with
residents
of
other
races.
The
small
number
of
homes
that
have
no
apparent
indication
of
cleaning
have
higher
window
dust
lead
loadings
than
homes
that
were
classified
as
showing
some
evidence
of
cleaning
or
appearing
clean.
Although
most
rooms
had
similar
window
dust
lead
loading
measurements,
measurements
were
somewhat
higher
in
adult
bedrooms
and
"
Other"
rooms
(
rooms
not
classified
as
kitchen,
living
room,
or
bedroom).
Samples
from
window
surfaces
that
were
not
smooth
and
cleanable
had
higher
lead
loading
than
samples
from
smooth
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
17
October
31,
2002
and
cleanable
surfaces.
Finally,
windows
with
vinyl
mini­
blinds
had
somewhat
higher
dust
lead
loading
than
windows
without
vinyl
mini­
blinds.
Differences
for
other
window
coverings
were
not
statistically
significant.

Figure
C.
10
shows
the
cumulative
distribution
of
the
maximum
window
sill
dust
lead
loading
within
homes.
The
figure
shows
four
cumulative
distributions:

1.
The
maximum
of
the
window
dust
lead
loading
measurements
within
a
home
(
thin
black
line).

2.
The
maximum
of
the
window
dust
lead
loading
measurements
or
predicted
values
for
missing
data
(
also
a
thin
black
line).

3.
The
maximum
measurement­
error­
adjusted
window
dust
lead
loading
across
the
sampled
rooms
(
thick
gray
line).

4.
The
maximum
measurement­
error­
adjusted
window
dust
lead
loading
across
all
rooms,
sampled
and
unsampled
(
thick
black
line).

For
various
reasons,
such
surfaces
being
inaccessible,
data
were
not
available
for
some
window
surfaces.
The
first
curve
assumes
that
the
lead
loading
on
all
surfaces
with
missing
data
is
negligible.
As
a
result
of
the
measurement
error
adjustment,
predicted
values
are
available
for
all
surfaces.

For
surfaces
with
no
data,
the
predicted
values
were
used.
The
second
curve,
to
the
right
of
the
first
curve,

shows
the
cumulative
distribution
of
the
best
estimate
of
the
lead
loading
on
all
window
surfaces,
i.
e.,
the
measurement
on
surfaces
with
data
and
the
predicted
values
on
surfaces
with
no
measurements.
The
predicted
values
are
referred
to
as
imputed
values.
The
imputation
generally
affects
the
lower
portion
of
the
distribution.

The
third
curve
shows
the
distribution
of
the
measurement
error
adjusted
estimates.
Since
measurement
error
will
generally
increase
the
maximum
within­
home
measurements,
the
effect
of
the
measurement
error
correction
is
to
slightly
reduce
estimated
maximum
within­
home
window
dust
lead
loading.
The
fourth
curve
shows
the
cumulative
distribution
of
the
measurement
error
corrected
measurements
after
accounting
for
the
incomplete
sampling
of
rooms.
These
values
will
be
referred
to
as
the
adjusted
values.
The
primary
difference
between
the
maximum
of
the
observed
window
sill
dust
lead
loading
measurements
and
the
final
adjusted
maximum
in
each
home
is
due
to
the
incomplete
sampling
of
rooms.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
18
October
31,
2002
Using
the
adjusted
values,
a
predicted
19
percent
of
homes
(
18
million
homes)
have
a
window
sill
dust
lead
loading
of
at
least
250
µ
g/
ft2
in
at
least
one
room.
This
is
about
five
percent
more
homes
than
estimated
using
the
actual
measurements.
A
predicted
22
percent
of
homes
(
21
million
homes)
have
a
window
trough
dust
lead
loading
of
at
least
800
µ
g/
ft2
in
at
least
one
room.
This
is
about
20
percent
more
than
estimated
using
the
actual
measurements.

Figure
C.
10
Cumulative
Distribution
of
the
Maximum
Within­
Home
Window
Sill
Dust
Lead
Loading
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%

1
10
100
1000
10000
100000
Maximum
within­
home
window
sill
dust
lead
loading
(
µ
g/
ft2)
Percent
of
homes
Measurements
Measurements
+
imputed
values
Adjusted
for
measurement
error
Adjusted
for
measurement
error
and
unsampled
rooms
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
19
October
31,
2002
Figure
C.
11
shows
the
cumulative
distribution
of
the
maximum
window
trough
dust
lead
loading
within
homes.
The
figure
shows
four
cumulative
distributions
for
the
measurements
(
thin
upper
thin
black
line),
the
measurements
plus
imputed
values
(
lower
thin
black
line),
the
measurement
error
corrected
values
for
the
sampled
rooms
(
gray
line)
and
the
final
adjusted
values
that
account
for
the
incomplete
sampling
of
rooms
Because
there
were
many
surfaces
for
which
window
trough
data
could
not
be
obtained,
there
are
relatively
large
differences
between
the
distributions
for
the
measurements
and
the
measurements
with
imputed
values.
As
with
the
window
sill
lead
loading,
the
measurement
error
adjustment
for
the
available
measurements
makes
only
a
small
difference
compared
to
the
effect
of
missing
data
and
the
incomplete
sampling
of
rooms.

Figure
C.
11
Cumulative
Distribution
of
the
Maximum
Within­
Home
Window
Trough
Dust
Lead
Loading
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%

1
10
100
1000
10000
100000
1000000
Maximum
within­
home
window
trough
dust
lead
loading
(
µ
g/
ft2)
Percent
of
homes
Measurements
Adjusted
for
measurement
error
and
unsampled
rooms
Also
adjusted
for
unsampled
rooms
Measurements
+
imputed
values
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
20
October
31,
2002
C.
3
Measurement
Error
 
Soil
Lead
Measurements
Soil
samples
were
taken
at
all
surveyed
homes
at
the
major
entrance
and
along
the
dripline
and
midyard
of
two
sides
of
the
home,
if
soil
was
present.
For
the
soil
measurement
error
correction,
the
objective
was
to
determine
the
number
and
percentage
of
homes
with
average
soil
lead
concentrations
above
a
selected
value
at
the
three
sample
sites
­
midyard,
dripline,
and
main
entrance.
64
Note
that
this
analysis
was
performed
on
preliminary
data,
before
the
play
area
survey
samples
were
collected.

Table
C.
2
describes
the
regression
model
used
for
different
categories
of
homes.


For
Category
I
homes,
there
was
no
soil
at
any
of
the
three
sample
sites,
and
so
no
model
was
required.
This
situation
occurred
if
all
areas
of
the
yard
were
covered
with
concrete,
asphalt,
or
rock.
Also,
a
specific
sample
site
could
have
no
soil
if
the
site
did
not
exist
(
for
example,
the
dripline
and
the
property
line
coincided
so
that
there
was
no
midyard
sample
site).


For
Category
II
homes,
at
least
one
of
the
sample
sites
had
soil,
but
there
were
no
soil
lead
measurements
for
the
home.
This
situation
could
arise
if
the
respondent
denied
permission
to
collect
soil
samples,
or
if
adverse
conditions
existed,
such
as
an
ongoing
storm,
frozen
ground,
the
presence
of
a
dog,
or
large
rocks
mixed
in
with
the
soil.
The
measurement
error
corrected
soil
lead
concentrations
are
the
predicted
values
from
the
regression
model.


For
Category
III
homes,
all
soil
measurements
were
equal
to
zero.
While
the
sample
detection
limit
was
determined
to
be
20
ppm,
the
laboratory
provided
an
estimate
of
the
soil
lead
for
all
samples
with
levels
below
the
detection
limit.
However,
negative
laboratory
estimates
were
reported
as
zero.
The
measurement
error
corrected
soil
lead
concentrations
are
assumed
to
be
less
than
the
detection
limit.


For
Category
IV
homes,
some
or
all
of
the
soil
measurements
were
equal
to
a
non­
zero
value
(
i.
e.,
a
value
at
or
more
than
the
detection
limit).
These
values
were
used
to
predict
soil
lead
concentrations
for
the
category
IV
and
category
II
homes.

64
The
average
of
the
available
midyard
and
average
of
available
dripline
samples
were
used
for
the
measurement
error
analysis,
regardless
of
which
side
of
the
house
they
were
collected.
That
is,
separate
assessments
were
not
made
for
midyard
and
dripline
areas
on
each
side
of
the
home.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
21
October
31,
2002
Table
C.
2
Regression
Model
Used
for
Different
Categories
of
Homes
Category
of
homes
Number
of
homes
Model
for
measurement
error
corrected
soil
concentrations
I.
Homes
with
no
soil
at
any
sample
site
45
Not
applicable.

II.
Homes
with
soil,
but
no
soil
measurements
8
Log
transformed
soil
lead
concentration
=
a
mean
for
each
combination
of
construction
year
category
and
soil
sample
location
and
a
mean
for
each
combination
of
construction
year
category
and
region.

III.
Homes
with
all
soil
lead
measurements
equal
to
zero
(
therefore
no
within­
home
variation)
33
All
measurements
assumed
to
be
less
than
the
detection
limit.

IV.
Homes
with
soil
lead
measurements,
some
or
all
of
which
are
nonzero
745
Log
transformed
soil
lead
concentration
=
a
mean
for
each
combination
of
construction
year
category
and
soil
sample
location,
a
mean
for
each
combination
of
construction
year
category
and
region,
and
a
mean
for
each
home
The
regression
analysis
predicts
the
approximate
median
of
the
soil
lead
concentrations.

Figures
C.
12
and
C.
13
show
the
relative
median
soil
lead
concentration
for
homes
within
each
construction
year
category
by
sample
location
and
region.
As
expected,
older
homes
have
higher
soil
lead
concentrations.
Concentrations
are
also
higher
on
average
in
the
northeast
region
and
lower
in
the
western
region
of
the
country.
Soil
lead
concentrations
are
higher
on
average
at
the
dripline
sample
location
and
lower
at
the
midyard
sample
location.
The
measurement
error
adjustment
procedures
excluded
three
percent
of
the
floor
dust
measurements
as
outliers.

As
part
of
the
exploratory
analysis
to
identify
the
model
for
the
data,
additional
variables
were
considered.
In
particular,
orientation
of
the
side
of
the
building
(
north,
east,
south,
or
west)
and
ground
cover
(
bare
soil,
grass,
ivy,
moss,
mulch,
and
other
or
unknown)
were
examined.
Neither
the
side
of
the
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
22
October
31,
2002
house
on
which
the
samples
were
taken
nor
the
ground
cover
was
a
significant
predictor
of
soil
lead
concentrations,
after
adjusting
for
the
effects
of
year
of
construction,
region,
and
sample
location.

Figure
C.
12
Predicted
Relative
Median
Soil
Lead
Concentrations
by
Construction
Year
Category
and
Sample
Location
(
based
on
regression
model)

0
50
100
150
200
250
300
350
400
450
1750­
1939
1940­
1959
1960­
1977
1978­
1998
Year
built
category
Relative
Estimated
median
soil
lead
concentration
Main
entry
Midyard
Dripline
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
23
October
31,
2002
Figure
C.
13
Predicted
Median
Soil
Lead
Concentrations
by
Construction
Year
Category
and
Region
(
based
on
regression
model)

0
50
100
150
200
250
300
350
400
450
1750­
1939
1940­
1959
1960­
1977
1978­
1998
Year
built
category
Relative
Estimated
median
soil
lead
concentration
Midwest
Northeast
South
West
Figure
C.
14
shows
the
cumulative
distribution
of
the
maximum
soil
lead
concentration
at
homes.
The
figure
shows
three
cumulative
distributions:


The
maximum
of
the
soil
lead
measurements
at
a
home
(
bottom
thin
black
line).


The
maximum
within
each
home
of
the
average
soil
lead
measurements
at
the
entrance,

dripline,
and
midyard
(
middle
gray
line).
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
24
October
31,
2002

The
maximum
measurement
error
corrected
soil
lead
measurements
(
top
thick
black
line).

Figure
C.
14
Cumulative
Distribution
of
the
Maximum
Soil
Lead
Concentration
for
All
Homes
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%

10
100
1000
10000
100000
Maximum
soil
lead
concentration
Percent
of
homes
Measurement
Mean
measurement
by
location
Adjusted
measurements
Note:
Play
area
soil
sample
results
were
not
included
in
the
analysis
for
Figure
C.
14.
Thus,
data
may
vary
slightly
from
that
presented
in
Chapter
6.

The
difference
between
the
first
and
second
curves
shows
the
effect
of
taking
replicate
soil
measurements
(
i.
e.
more
than
one
sample
for
a
given
sample
location
at
a
home).
As
more
measurements
are
taken,
it
is
more
likely
that
a
sample
will
be
taken
which
has
an
unusually
high
measurement
(
either
due
to
laboratory
variation
or
due
to
sampling
a
small
area
with
a
locally
high
concentration).
The
second
curve
is
most
comparable
to
the
third
curve.
The
difference
between
the
second
and
the
third
curve
is
due
to
the
measurement
error
correction.
The
fact
that
the
third
(
measurement
error
corrected)
curve
is
to
the
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
C­
25
October
31,
2002
left
of
the
other
curve
is
because,
after
correcting
for
measurement
error,
the
percentage
of
homes
judged
to
have
soil
lead
concentrations
above
any
selected
value
is
decreased.

Using
the
measurement
error
corrected
values,
an
estimated
5.6
percent
of
homes
with
soil
(
about
5.3
million
homes)
have
soil
lead
concentrations
above
1,200
ppm
in
one
or
more
of
the
sampling
locations
(
dripline,
midyard,
and
main
entrance).
This
is
about
two
million
fewer
homes
than
estimated
using
the
observed
soil
lead
measurements.
Even
fewer
homes
have
maximum
soil
lead
concentrations
over
1,200
ppm
on
bare
soil.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
D­
1
October
14,
2002
APPENDIX
D
Calculation
of
Soil
Related
Estimates
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
D­
2
October
14,
2002
CALCULATION
OF
SOIL
RELATED
ESTIMATES
In
the
main
survey,
soil
samples
were
collected
near
the
main
entrance,
along
the
drip
line
and
in
the
midyard
on
the
side
of
the
house
with
the
main
entrance,
and
along
the
dripline
and
in
the
mid­
yard
on
a
second
randomly
selected
side
of
the
home.
In
a
follow­
on
survey
of
children's
play
areas
involving
a
subset
of
the
homes
in
the
main
survey,
residents
were
asked
where
children
play
around
the
home.
If
there
was
play
equipment
at
the
home
or
soil
samples
were
not
previously
collected
in
children's
play
areas,
additional
soil
samples
were
collected
at
the
home
in
a
follow­
up
visit.
In
the
play
area
survey,
soil
samples
were
collected
from
below
play
equipment
and
from
areas
designated
by
the
respondent
as
children's
play
areas.
The
main
survey
has
data
from
831
homes.
The
follow­
on
survey
has
information
on
375
homes.
Details
of
the
survey
procedures
are
described
in
the
Design
and
Methodology
report.

The
tables
in
this
report
are
based
on
data
from
the
831
homes
whenever
possible.
However,
for
estimates
involving
soil
in
children's
play
areas,
data
was
only
available
from
375
homes.
Therefore,
estimates
not
involving
soil
were
based
on
the
main
survey
data.
Estimates
involving
only
soil
were
based
on
the
play
area
survey
data.
For
estimates
that
involve
both
soil
data
and
data
from
other
locations,
such
as
the
number
of
homes
with
significant
lead­
based
paint
(
LBP)
hazards,
estimates
from
the
main
survey
were
combined
with
estimates
from
the
play
area
survey,
as
described
below.

To
construct
estimates
of
significant
LBP
hazards
using
as
much
of
the
data
as
possible
the
following
procedure
was
used.
Estimates
of
the
number
of
homes
with
significant
LBP
hazards
due
to
paint,
dust,
and
soil
sources
other
that
play
soil
were
calculated
from
the
831
homes
from
the
main
survey.
Estimates
of
the
number
of
homes
with
significant
LBP
hazards
due
only
to
soil
hazards
in
play
areas
were
calculated
from
the
375
homes
in
the
play
area
survey.
These
two
estimates
were
added
together
to
obtain
the
combined
estimate
of
the
number
of
homes
with
significant
LBP
hazards
from
any
source.

For
example,
the
estimated
number
of
homes
with
a
significant
LBP
hazard
is
24,026
thousand.
This
is
the
sum
of
23,312
thousand
homes
with
paint
hazards,
dust
hazards,
or
soil
lead
hazards
in
non­
play
areas
(
based
on
data
from
831
homes)
and
714
thousand
homes
with
significant
LBP
hazards
in
play
areas
only
(
based
on
data
from
375
homes).

The
variance
of
the
combined
estimate
depends
on
the
portion
of
the
estimate
contributed
by
the
two
data
sources,
the
variance
of
each
estimate,
and
the
correlation
between
the
estimates.
Calculation
of
the
variance
of
the
combined
estimate
is
difficult
because
the
correlation
is
difficult
to
estimate.
However,
the
estimate
from
the
main
survey
contributes
97%
of
the
combined
estimate.
As
a
result,
the
variance
of
the
combined
estimate
is
primarily
due
to
uncertainty
in
the
estimate
from
the
main
survey.
Therefore,
the
confidence
intervals
in
the
tables
involving
lead
hazards,
are
based
on
the
confidence
intervals
calculated
from
the
main
survey.
The
resulting
confidence
interval
will
tend
to
underestimate
the
true
variance
by
a
small
amount.
Thus,
the
confidence
intervals
for
the
number
of
homes
are
calculated
as
follows:

1)
The
confidence
interval
and
estimate
for
the
number
of
homes
with
significant
LBP
hazards
in
all
but
play
soil
are
calculated
from
the
main
survey
data.

2)
The
estimate
for
the
number
of
additional
homes
with
a
significant
LBP
hazards
in
only
the
play
soil
is
calculated
from
the
play
survey
data.
National
Survey
of
Lead
Final
Report,
Vol.
I
and
Allergens
in
Housing
Analysis
of
Lead
Hazards
WESTAT
D­
3
October
14,
2002
3)
The
estimate
from
the
play
survey
data
is
added
to
the
estimate
from
the
main
survey
to
get
the
combined
estimate,
and
4)
The
estimate
from
the
play
survey
data
is
added
to
the
confidence
limits
for
the
estimate
from
the
main
survey
to
approximate
the
confidence
limits
for
the
combined
estimate.
