CONTROL TECHNOLOGY AND EXPOSURE ASSESSMENT FOR

ELECTRONIC RECYCLING OPERATIONS

UNITED STATES PENITENTIARY, LEWISBURG, PA

REPORT DATE:

January 2009

FILE NO.:

EPHB 326-17a

PRINCIPAL AUTHORS:

Dan Almaguer, MS

G. Edward Burroughs, PhD, CIH, CSP

Alan Echt, MPH, CIH

David Marlow

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

Division of Applied Research and Technology

4676 Columbia Parkway, R5

Cincinnati, Ohio  45226

SITES SURVEYED: 								UNICOR Recycling Operations 

 											Federal Correctional Institution 

 											Lewisburg, PA 

 

NAICS: 										562920 

SURVEY DATE:  								January 28 – 31, 2008

 

SURVEY CONDUCTED BY: 						Dan Almaguer, MS 

											Ed Burroughs, Ph.D., CIH, CSP 

											Dave Marlow 

         

 

 

 

 

 

 

 

 

DISCLAIMER

 

Mention of company names or products does not constitute endorsement by
the Centers for Disease Control and Prevention. 

 

The findings and conclusions in this report do not necessarily reflect
the views of the National 

Institute for Occupational Safety and Health. 

 

CONTENTS

Executive Summary
………………………………………………………………
… 	  6

I. Introduction
………………………………………………………………
………. 	  8

II. Process Description
………………………………………………………………
10

III. Sampling and Analytical Methods
……………………………………………….	12

IV. Occupational Exposure Limits and Health Effects
………………………………	14

 A. Exposure Criteria for Occupational Exposure to Airborne Chemical
Substances .	16 

  Barium
………………………………………………………………
………………	17

  Beryllium
………………………………………………………………
……………	17

  Cadmium
………………………………………………………………
……………	17

  Lead
………………………………………………………………
…………………	18

 
Nickel…………………………………………………………
……………………..	19

  Airborne
Particulate……………………………………………………
……………	19

 B. Surface Contamination Criteria 
………………………………………………….	19

  Lead
………………………………………………………………
…………………	20

  Beryllium
………………………………………………………………
……………	21

  Cadmium
………………………………………………………………
…………….	21

  Nickel
………………………………………………………………
…………….…	21

  Barium
………………………………………………………………
………………	21

C. Noise Exposure Criteria
…………………………………………………………..	21

V. Results and Discussion
……………………………………………………………	22

A.  Air Sample Results
………………………………………………………………
.	22

B. Surface Wipe Sample Results
…………………………………………………….	23

C. Sound Level
Measurements……………………………………………………
….	24

D. Local Exhaust System Measurements  
……………………………………………	24

VI. Conclusions and Recommendations
………………………………………………	25

 References……………………………………………………
………………………..	28

 

Tables, Appendices and Figures

Table 1 Summary Statistics for Airborne Metal Measurements
………………………  	32

Table 2 Personal Breathing Zone and Area Air Sample Results
……………………… 	33

Table 3 Respirable Air Sample
Results………………………………………………... 	34

Table 4 Wipe Sample Results
…………………………………………………………  	35

Table 5 Noise Exposure Measurements
………………………………………………  	36

  

 

Appendix A Occupational Exposure Criteria for Metal/Elements
……………………. 	38

Appendix B Personal Breathing Zone and Area Air Sample
Results…………………. 	39

Appendix C Metallic Respirable Air Sample Results
………………………………… 	42

Appendix D Wipe Sample Results 
……………………………………………………	44

 

 

Figure I Lewisburg UNICOR Factory Floor Plan, Warehouse 

      and associated areas
………………………………………………………………
.  	45

Figure II Lewisburg UNICOR Factory Floor Plan, Disassembly

      and glass breaking areas
…………………………………………………………... 
46

Figure III Lewisburg Glass Breaking Area
……………………………………………	47

Figure IV Lewisburg Glass Breaking Booth Work Stations
…………………………. 	48

 

EXECUTIVE SUMMARY

Researchers from the National Institute for Occupational Safety and
Health (NIOSH) conducted a study of the recycling of electronic
components at the Federal Prison Industries facilities (aka, UNICOR) in
Lewisburg, PA in January 2008 to assess workers’ exposures to metals
and other occupational hazards, including noise, associated with these
operations. 

The electronics recycling operations at Lewisburg can be organized into
four production processes: a) receiving and sorting, b) disassembly, c)
glass breaking operations, and d) packaging and shipping.  A fifth
operation, cleaning and maintenance, was also addressed but is not
considered a production process per se.  It is known that lead (Pb),
cadmium (Cd), and other metals are used in the manufacturing of
electronic components and pose a risk to workers involved in recycling
of electronic components if the processes are not adequately controlled
or the workers are not properly trained and provided appropriate
personal protective clothing and equipment.  

Methods used to assess worker exposures to metals during this evaluation
included: personal breathing zone sampling for airborne metals and
particulate, and surface wipe sampling to assess surface contamination. 
Samples were analyzed for 31 metals with five selected elements (barium,
beryllium, cadmium, lead and nickel) given emphasis.  Noise exposures
were determined using sound pressure level monitors.  

The results of air sampling conducted during this visit indicated no
overexposures of workers to metals above the most stringent occupational
exposure limits.  Exposures to airborne metals during the filter
change-out maintenance operation (the task of primary concern in this
evaluation) were also well below the most stringent occupational
exposure limits. 

Although beryllium is used in consumer electronics and computer
components, such as disk drive arms (beryllium-aluminum), electrical
contacts, switches, and connector plugs (copper-beryllium) and printed
wiring boards [Willis and Florig 2002, Schmidt 2002], most beryllium
“in consumer products is used in ways that are not likely to create
beryllium exposures during use and maintenance” [Willis and Florig
2002].  This may account for the fact that beryllium in this study was
not detected at levels above the detection limit of the analytical
method.  The removal and sorting of components seen here is typical of a
maintenance activity (components are removed from the cases and sorted,
rather than removed and replaced).  Other e-recycling activities that
include further processing, such as shredding of the components, may
produce higher exposures to beryllium but shredding (except as a means
to destroy memory devices) does not occur at this facility.

Samples collected during routine daily disassembly operations and glass
breaking operations were less than 10% of the OSHA PELs for both Cd and
Pb.  Unless specified, results of samples presented are for the duration
of the sample and not calculated on an 8 hour time weighted average
basis.

  

Lead was detected on surface wipe samples in excess of recommended
levels, although in 2 of 3 instances it was concluded that this was
existing contamination on materials coming into the workplace.  Cadmium
and other heavy metals were detected in the surface wipe and bulk dust
samples.  There are few established standards available for wipe samples
with which to compare these data although the samples collected were
below recommended maximum levels which do exist.  The wipe sample
results generally cannot be used to determine the source of the
contamination.  They only estimate the surface contamination present at
the time the sample was collected.

Eight-hour time weighted average measurements of noise in this workplace
identified several instances where exposure was greater than the REL and
TLV of 85 dBA, although none which exceeded the PEL of 90 dBA.

Recommendations resulting from this study include:

The implementation of a site-specific health and safety program at
Lewisburg that includes a noise reduction program.

The respiratory protection program for this facility should be evaluated
to ensure that it complies with OSHA regulations.  

Attention should be focused on practices to prevent accidental ingestion
of lead and other metals. 

Management should evaluate the feasibility of providing and laundering
work clothing for all workers in the recycling facility.

Change rooms should be equipped with separate storage facilities for
work clothing and for street clothes to prevent cross-contamination.   

All UNICOR operations should be evaluated from the perspective of
health, safety and the environment in the near future. 

A comprehensive program is needed within the Bureau of Prisons to assure
both staff and inmates a safe and healthy workplace.

 

I.  INTRODUCTION

 

Researchers from the National Institute for Occupational Safety and
Health (NIOSH) conducted a study of exposures to metals and other
occupational hazards associated with the recycling of electronic
components at the Federal Prison Industries (aka, UNICOR) in Lewisburg,
PA.(  The principal objectives of this study were: 

 

1. To measure full-shift, personal breathing zone exposures to metals
including barium (Ba), beryllium (Be), cadmium (Cd), lead (Pb) and
nickel (Ni);     

2. To evaluate contamination of surfaces in the work areas that could
permit skin contact or allow re-suspension of metals into the air;   

3. To identify and describe the control technology and work practices in
use in operations  associated with occupational exposures to metals, as
well as to determine additional controls,  work practices, substitute
materials, or technology that can further reduce occupational 
exposures;   

4. To evaluate the use of personal protective equipment (PPE) in
operations involved in the recycling of electronic components; and,   

5. To determine the size distribution of airborne particles for purposes
of toxicity and control. 

 

Other objectives such as a preliminary evaluation of noise exposures and
visual observations of undocumented hazards, were secondary to those
listed above but are discussed as appropriate in this document. 

 

An initial walk-through evaluation was conducted in May 2007 to observe
operations at Lewisburg in order to facilitate subsequent testing.  In
January 2008 an in-depth evaluation was conducted during which two full
shifts of environmental monitoring were conducted for the duration of
normal plant operations, and monitoring also was conducted during
cleaning and maintenance as described in Section II (Process
Description) and Section III (Sampling and Analytical Methods).   

 

Computers and their components contain a number of hazardous substances.
 Among these are  “platinum in circuit boards, copper in transformers,
Ni and cobalt in disk drives, barium  and cadmium coatings on computer
glass, and lead solder on circuit boards and video screens” 
[Chepesiuk 1999].  The Environmental Protection Agency (EPA) notes that
“In addition to lead, electronics can contain chromium, cadmium,
mercury, beryllium, nickel, zinc, and brominated flame retardants”
[EPA 2008].  Schmidt [2002] linked these and other substances to their
use and location in the “typical” computer: lead used to join metals
(solder) and for radiation protection, is present in the cathode ray
tube (CRT) and printed wiring board (PWB).  Aluminum, used in structural
components and for its conductivity, is present in the housing, CRT,
PWB, and connectors.  Gallium is used in semiconductors; it is present
in the PWB.   Ni is used in structural components and for its
magneticity; it is found in steel housing, CRT and PWB.  Vanadium
functions as a red-phosphor emitter; it is used in the CRT.   Be, used
for its thermal conductivity, is found in the PWB and in connectors. 
Chromium, which has decorative and hardening properties, may be a
component of steel used in the housing.  Cd, used in Ni-Cad batteries
and as a blue-green phosphor emitter, may be found in the housing, PWB
and CRT.  Cui and Forssberg [2003] note that Cd is present in components
like SMD chip resistors, semiconductors, and infrared detectors. 
Mercury may be present in batteries and switches, thermostats, sensors
and relays [Schmidt 2002, Cui and Forssberg 2003], found in the housing
and PWB.  Arsenic, which is used in doping agents in transistors, may be
found in the PWB [Schmidt 2002]. 

 

Lee et al. [2004] divided the personal computer into three components,
the main machine, monitor, and keyboard.  They further divided the CRT
of a color monitor into the “(1) panel glass (faceplate), (2) shadow
mask (aperture), (3) electronic gun (mount), (4) funnel glass and (5)
deflection yoke.  Lee et al. [2004] note that panel glass has a high Ba
concentration (up to 13%) for radiation protection and a low
concentration of Pb oxide.  The funnel glass has a higher amount of Pb
oxide (up to 20%) and a lower Ba concentration.  They analyzed a 14-in
Philips color monitor by electron dispersive spectroscopy and reported
that the panel contained silicon, oxygen, potassium, Ba and aluminum in
concentrations greater than 5% by weight, and titanium, sodium, cerium,
Pb, zinc, yttrium, and sulfur in amounts less than 5% by weight. 
Analysis of the funnel glass revealed greater than 5% silicon, oxygen,
iron and Pb by weight, and less than 5% by weight potassium, sodium, Ba,
cerium, and carbon.   Finally, Lee et al. [2004] noted that the four
coating layers are applied to the inside of the panel glass, including a
layer of three fluorescent colors (red, blue and green phosphors) that
contain various metals, and a layer of aluminum film to enhance
brightness. 

 

German investigators [BIA 2001, Berges 2008a] broke 72 cathode-ray tubes
using three techniques (pinching off the pump port, pitching the anode
with a sharp item, and knocking off the cathode) in three experiments
performed on a test bench designed to measure emissions from the
process.  Neither Pb nor Cd was detected in the total dust, with one
exception, where Pb was detected at a concentration of 0.05 mg/cathode
ray tube during one experiment wherein the researchers released the
vacuum out of 23 TVs by pinching off the pump port [BIA 2001, Berges
2008b].  They described this result as “sufficiently low that a
violation of  the German atmospheric limit value of 0.1 mg/m3 need not
generally be anticipated” [BIA  2001].  The researchers noted that
“the working conditions must be organized such that skin contact with
and oral intake of the dust are excluded” [BIA 2001]. 

 

However, there are few articles documenting occupational exposures among
electronics recycling workers.  Sjödin et al. [2001] and
Pettersson-Julander et al. [2004] have reported potential exposures of
electronics recycling workers to flame retardants while they dismantled
electronic products, although no retardants were used in this facility. 
Recycling operations in the Lewisburg facility are limited to
disassembly and sorting tasks, with the exception of breaking CRTs and
stripping insulation from copper wiring. Disassembly and sorting
probably pose less of a potential hazard from retardants as well as
metals for workers than tasks that disrupt the integrity of the
components, such as shredding or de-soldering PWBs.  

 

The process of greatest concern was the glass breaking operation
(described below) that releases visible emissions into the workroom
atmosphere.  Material safety data sheets and other information on
components of CRTs broken in this operation listed several metals,
including Pb, Cd, Be and Ni.  In addition, FOH investigators expressed a
particular interest in Ba. 

II. PROCESS DESCRIPTION

The recycling of electronic components at the United States Penitentiary
(USP) Lewisburg  is done in one extended building that is part of the
prison camp outside of the main prison.  That building is composed of
three sections:  1) a receiving and warehousing area which also contains
offices and areas where laptop refurbishing is done; 2) a middle or
center section where most of the disassembly is performed; and 3) a
third area where some disassembly is done which also houses the glass
breaking operation.  Diagrams of these work areas are shown in Figures I
and II with an enlargement of the glass breaking operation in Figure
III.  These figures provide a general visual description of the layout
of the work process, although workers often moved throughout the various
areas in the performance of their tasks.

The electronics recycling operations can be organized into four
production processes: a) receiving and sorting, b) disassembly, c)
(glass breaking operation), and d) packaging and shipping.  A fifth
operation, cleaning and maintenance will also be addressed but is not
considered a production process per se.    

Incoming materials to be recycled are received at the warehouse (Figure
I) where they are examined and sorted.  During this evaluation it
appeared that the bulk of the materials received were computers, either
desktop or notebooks, or related devices such as printers.  Some items,
notably notebook computers, could be upgraded and resold, and these
items were sorted out for that task.      

After electronic memory devices (e.g., hard drives, discs, etc.) were
removed and degaussed or destroyed, computer central processing units
(CPUs), servers and similar devices were sent for disassembly; monitors
and other devices (e.g., televisions) that contain CRTs were separated
and sent for disassembly and removal of the CRT.  Printers, copy
machines and any device that could potentially contain toner, ink, or
other expendables were segregated and inks and toners were removed in
the warehouse prior to being sent to the disassembly area.      

In the disassembly process (see Figures II and III), external cabinets,
usually plastic, were removed from all devices and segregated.  Valuable
materials such as copper wiring and aluminum framing were removed and
sorted by grade for further treatment if necessary.  Components such as
circuit boards or chips that may have value or may contain precious
metals such as gold or silver were removed and sorted. With few
exceptions each of the approximately 85 workers in the main factory will
perform all tasks associated with the disassembly of a piece of
equipment into the mentioned components with the use of powered and
non-powered hand tools (primarily screwdrivers and wrenches), with a few
workers collecting the various parts and placing them into the proper
collection bin.  Work tasks included removing screws and other fasteners
from cabinets, unplugging or clipping electrical cables, removing
circuit boards, and using whatever other methods necessary to break
these devices into their component parts.  Essentially all of these
component parts are sorted and separated, then repackaged and sold for
some type of recycling. 

Personal protective equipment in these first two operations consisted of
safety glasses and gloves where needed.  Control of dust and surface
contamination was accomplished primarily by good housekeeping procedures
which included brushing dust from work tables and sweeping floors up to
twice a day.  Protective clothing and housekeeping were more stringent
in the third operation and are described below.      

The third production process to be evaluated was the glass breaking
operation where CRTs from computer monitors and TVs were sent for
processing.  This was an area of primary interest in this evaluation due
to concern from staff, review of process operations and materials
involved, and observations during an initial walk-through.  This was the
only process where local exhaust ventilation was utilized or where
respiratory protection was in universal use.  Workers in other locations
would wear eye protection and occasionally would voluntarily wear a
disposable respirator.  Additional PPE in the glass breaking operation
included Tyvek™ coveralls, hand and arm protection for broken glass,
and powered air-purifying respirators (PAPRs).  Glass breaking was done
in an enclosed booth (see Figure III), approximately 25 ft by 14 feet,
located as shown in Figure II.  The local exhaust ventilation system,
contained in that booth, consisted of 2 reverse flow horizontal filter
modules (model HFM24-ST/RD/SP, Atmos-Tech Industries, Ocean, NJ), for
funnel glass and for panel glass.  These units were 16 ga. galvanized
steel with filter faces approximately 26 inches high and 51 inches wide.
 The units were 36 inches deep.  Filtration was achieved with three 16
inch x 24 inch x 1 inch pleated pre-filters preceding a single 24” x
48” x 6” high efficiency particulate air (HEPA) filter. Air was
exhausted through the HEPA filter back into the glass breaking booth. 
Exhaust fans and air filters were placed on top of the glass breaking
booth to produce air movement between the booth and the general work
area.  

Workers in the glass breaking operation wore PAPRs, (MB14-72 PAPR w/
Super Top Hood, Woodsboro, MD, Global Secure Safety), work boots, gloves
and coveralls.  Of the UNICOR recycling facilities evaluated to date,
Lewisburg has the most adequate arrangement for donning and doffing
personal protective clothing and equipment.  A typical work area that
requires the use of protective clothing includes: a) an outer change
area where workers can remove and store their street clothing and don
their work clothing and personal protective equipment before entering
the work area; b) upon completion of their work, workers exit the work
area through a “decon” area (e.g., where they vacuum the outer
surface of their clothes); c) they then enter a separate, “dirty”
locker area, where their soiled work clothes are removed and placed in
receptacles for cleaning or disposal.  The workers then pass through a
shower area, and then enter the outer change area, where they change
into their street clothes again.  In some cases (e.g., asbestos
removal), respirators are worn into the shower and not removed until the
exterior surfaces are rinsed.

CRTs that had been removed from their cases were trucked to this process
area in large boxes and were fed into the glass-breaking booth through
an opening on the side and placed on a metal grid for breaking (see
Figure IV).  As the CRT moved from right to left in the booth the
electron gun was removed by tapping with a hammer to break it free from
the tube, then a series of hammer blows was used to break the funnel
glass and allow it to fall through the metal grid into large Gaylord
boxes (cardboard boxes approximately 3 feet tall designed to fit on a
standard pallet) positioned below the grid.  This was done at the first
(right) station in Figure IV.  The CRT was moved to the second (left)
station where any internal metal framing or lattice was removed before
the panel glass was broken with a hammer and also allowed to fall into a
Gaylord box.  During the two days of sampling 551 CRTs were broken (293
on day 1 and 258 on day 2).  No count was made by the survey team
regarding the number of color vs monochrome monitors broken.

The final production process, packing and shipping, moved the various
materials segregated during the disassembly and glass breaking processes
to the loading dock to be sent to contracted purchasers of those
individual materials.  To facilitate shipment some bulky components such
as plastic cabinets or metal frames were placed in a hydraulic bailer to
be compacted for easier shipping.  Other materials were boxed and
removed for subsequent sale to a recycling operation.

n similar operations.  Two workers in Tyvek™ coveralls, gloves and
PAPRs remove both sets of filters, clean the system, and replace the
filters.  They are assisted by two additional workers who wear Tyvek™
coveralls and gloves while working outside the glass breaking enclosure.
 The filter change is a maintenance operation that occurs at
approximately monthly intervals during which the ventilation system is
shut down and all filters are removed and replaced. Initially the
exhaust system components, including the accessible surfaces of the
filters, are vacuumed with a HEPA vacuum.  Then the filters are removed
and bagged for disposal, and the area inside the filter housing is
vacuumed.  New filters are inserted to replace the old ones, the LEV
system is reassembled, and any residual dust is removed with a HEPA
vacuum.  

III. SAMPLING AND ANALYTICAL METHODS

Air sampling techniques

Methods used to assess worker exposures in this workplace evaluation
included: personal breathing zone and area sampling for airborne metals
and particulate (total and respirable fractions); and surface wipe
sampling to assess surface contamination.  Material safety data sheets
and background information on CRTs and other processes in this operation
listed several metals, including Pb, Cd, Be and Ni.  Additionally, FOH
personnel expressed specific interest in Ba.  Therefore emphasis is
placed on those five analytes in this report.

Personal breathing zone and general area samples were collected and
analyzed for total airborne particulate and metals.  Samples were
collected for as much of the work shift as possible with durations
(ranging from 20% to 90% of an 8-hour work shift) indicated below in
respective tables of results.  Samples were collected at a flow rate of
3 liters/minute (L/min) using a calibrated battery-powered sampling pump
(Model 224, SKC Inc., Eighty Four, PA) connected via flexible tubing to
a 37-mm diameter filter (0.8 μm pore-size mixed cellulose ester) in a
3-piece, clear plastic cassette sealed with a cellulose shrink band.  It
is possible to determine both airborne particulate as well as metals on
the same sample by using a pre-weighed filter and then post-weighing
that filter to determine weight gain according to NIOSH Method 0500
[NIOSH 1994] before subsequent analysis for metals using inductively
coupled plasma spectroscopy (ICP) according to NIOSH Method 7303 [NIOSH
1994] with modifications.  This combination of analytical techniques
produces a measure for dust and a measure of 31 elements, including the
five of particular interest mentioned above.  Because Method 7303 is an
elemental analysis, the laboratory report describes the amount of the
element present in each sample (μg/sample) as the element, regardless
of the compound in which the element was present in the sample.

Because there is evidence that the presence of an ultrafine component
increases the toxicity for chronic beryllium disease and possibly other
toxic effects, information on the aerosol size distribution was
collected to assist in evaluation of the potential exposure [McCawley et
al. 2001].  A subset of samples was collected using BGI cyclones (BGI
Incorporated, Waltham, MA) at a flow rate of 4.2 lpm and analysis
according to NIOSH Methods 0600 and 7303 [NIOSH 1994] to determine the
particulate and metal concentrations, respectively, in the respirable
size range.

Bulk sampling and analysis

Unlike the other evaluations conducted in UNICOR facilities, no bulk
samples were collected by NIOSH researchers at Lewisburg, but rather
wipe samples were
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 for storage until analysis.  Ghost Wipes™ were sent to the laboratory
to be analyzed for metals according to NIOSH Method 9102 [NIOSH 1994].
Palintest wipes were analyzed for Be using the Quantech Fluorometer
(Model FM109515, Barnstead International, Dubuque, Iowa) for
spectrofluorometric analysis by NIOSH Method 9110 [NIOSH 1994]. 

Local Exhaust Ventilation Characterization Methods

Methods used to evaluate the local exhaust ventilation system included
measuring air velocity at the face of each of the reverse flow
horizontal filter modules (HFMs) inside the glass-breaking area, and
observing air flows at the plastic curtains enclosing the glass-breaking
operation.  A Velocicalc Plus Model 8388 thermal anemometer (TSI
Incorporated, St. Paul, MN) was used to measure air speeds at the face
of each HFM.  A Wizard Stick smoke device (Zero Toys, Inc., Concord, MA)
was used to visualize air flow.

The face velocity tests were performed by dividing the face of the HFM
into 12 rectangles of equal area and measuring the velocity at the
center of each square.  Face velocities were taken at each center point
averaged over a period of 30 seconds, using a 5-second time averaging
setting on the instrument.  The metal grid in front of the pre-filters
was used to support the edge of the probe, and the researcher stood to
one side to avoid obstructing air flow.  To measure the velocities
achieved by the control at each center point, the anemometer probe was
held perpendicular to the air flow direction at those points.  The same
measurements were repeated at the front edge of the plastic strip
curtains enclosing the area immediately in front of each HFM to
determine the capture velocity at that point.

Smoke was released as the strips of plastic curtain enclosing the glass
breaking booth were parted to qualitatively evaluate the air flow
patterns and determine areas of concern.  By releasing smoke at these
points the path of the smoke, and thus any airborne material potentially
released at that point, could be qualitatively determined.

Sound pressure measurements

An initial assessment of noise levels during various tasks in all
operations was made during the initial walk-through study using a hand
held sound level meter.  This brief sound-level survey was used to
determine where to target noise dosimetry during the follow-up study. 
During the follow-up study time weighted average noise exposures were
determined using personal dosimeters (Quest Technologies model Q300,
Oconomowoc, WI) capable of simultaneously logging sound pressure levels
under three sets of parameters.  For this evaluation data are reported
using both the Occupational Safety and Health Administration (OSHA) and
NIOSH parameters as follows:

	OSHA	NIOSH

Criteria (dB)	90	85

Exchange rate	5	3

Threshold	80	0

Weight	A	A

Time constant	Slow	Slow

All dosimeters and sound level meters were calibrated on-site prior to
use with a 110 dB source and data were downloaded to a laptop computer.

  

Observations regarding work practices and use of personal protective
equipment were recorded.  Information was obtained from conversations
with the workers and management to determine if the sampling day was a
typical workday to help place the sampling results in proper
perspective.  

OCCUPATIONAL EXPOSURE LIMITS AND HEALTH EFFECTS

In evaluating the hazards posed by workplace exposures, NIOSH
investigators use mandatory and recommended occupational exposure limits
(OELs) for specific chemical, physical, and biological agents.
Generally, OELs suggest levels of exposure to which most workers may be
exposed up to 10 hours per day, 40 hours per week for a working lifetime
without experiencing adverse health effects.  It is, however, important
to note that not all workers will be protected from adverse health
effects even though their exposures are maintained below these levels. 
A small percentage may experience adverse health effects because of
individual susceptibility, a pre-existing medical condition, and/or
hypersensitivity (allergy). In addition, some hazardous substances may
act in combination with other workplace exposures, the general
environment, or with medications or personal habits of the worker to
produce health effects even if the occupational exposures are controlled
at the level set by the exposure limit. Combined effects are often not
considered in the OEL. Also, some substances can be absorbed by direct
contact with the skin and mucous membranes in addition to being inhaled,
thus contributing to the overall exposure. Finally, OELs may change over
the years as new information on the toxic effects of an agent become
available.

Most OELs are expressed as a time-weighted average (TWA) exposure. A TWA
refers to the average exposure during a normal 8- to 10-hour workday.
Some chemical substances and physical agents have recommended short-term
exposure limits (STEL) or ceiling values where there are health effects
from higher exposures over the short-term. Unless otherwise noted, the
STEL is a 15-minute TWA exposure that should not be exceeded at any time
during a workday, and the ceiling limit is an exposure that should not
be exceeded at any time, even instantaneously.

 

In the U.S., OELs have been established by Federal agencies,
professional organizations, state and local governments, and other
entities. Some OELs are mandatory, legal limits; others are
recommendations. The U.S. Department of Labor Occupational Safety and
Health Administration (OSHA) Permissible Exposure Limits (PELs) [29 CFR
1910 (general industry); 29 CFR 1926 (construction industry); and 29 CFR
1915, 1917 and 1918 (maritime industry)] are legal limits that are
enforceable in workplaces covered under the Occupational Safety and
Health Act and in Federal workplaces under Executive Order 12196 [NARA
2008]. NIOSH Recommended Exposure Limits (RELs) are recommendations that
are made based on a critical review of the scientific and technical
information available on the prevalence of hazards, health effects data,
and the adequacy of methods to identify and control the hazards.
Recommendations made through 1992 are available in a single compendium
[NIOSH 1992]; more recent recommendations are available on the NIOSH Web
site (http://www.cdc.gov/niosh). NIOSH also recommends preventive
measures (e.g., engineering controls, safe work practices, personal
protective equipment, and environmental and medical monitoring) for
reducing or eliminating the adverse health effects of these hazards. The
NIOSH Recommendations have been developed using a weight of evidence
approach and formal peer review process. Other OELs that are commonly
used and cited in the U.S. include the Threshold Limit Values (TLVs) ®
recommended by the American Conference of Governmental Industrial
Hygienists (ACGIH) ®, a professional organization [ACGIH 2008]. ACGIH®
TLVs® are considered voluntary guidelines for use by industrial
hygienists and others trained in this discipline “to assist in the
control of health hazards.” Workplace Environmental Exposure Levels
(WEELs) are recommended OELs developed by the American Industrial
Hygiene Association (AIHA), another professional organization. WEELs
have been established for some chemicals “when no other legal or
authoritative limits exist” [AIHA 2007]. 

Employers should understand that not all hazardous chemicals have
specific OSHA PELs and for many agents, the legal and recommended limits
mentioned above may not reflect the most current health-based
information.  However, an employer is still required by OSHA to protect
their employees from hazards even in the absence of a specific OSHA PEL.
In particular, OSHA requires an employer to furnish employees a place of
employment that is free from recognized hazards that are causing or are
likely to cause death or serious physical harm [Occupational Safety and
Health Act of 1970, Public Law 91–596, sec. 5(a)(1)].  Thus, NIOSH
investigators encourage employers to make use of other OELs when making
risk assessment and risk management decisions to best protect the health
of their employees.  NIOSH investigators also encourage the use of the
traditional hierarchy of controls approach to eliminating or minimizing
identified workplace hazards.  This includes, in preferential order, the
use of: (1) substitution or elimination of the hazardous agent, (2)
engineering controls (e.g., local exhaust ventilation, process
enclosure, dilution ventilation) (3) administrative controls (e.g.,
limiting time of exposure, employee training, work practice changes,
medical surveillance), and (4) personal protective equipment (e.g.,
respiratory protection, gloves, eye protection, hearing protection). 

Both the OSHA PELs and ACGIH® TLVs® address the issue of combined
effects of airborne exposures to multiple substances [29 CFR
1910.1000(d)(1)(i), ACGIH 2008].  ACGIH® [2008] states:

When two or more hazardous substances have a similar toxicological
effect on the same target organ or system, their combined effect, rather
than that of either individually, should be given primary consideration.
 In the absence of information to the contrary, different substances
should be considered as additive where the health effect and target
organ or system is the same. That is, if the sum of

 			Eqn. 1

exceeds unity, the threshold limit of the mixture should be considered
as being exceeded (where C1 indicates the observed atmospheric
concentration and T1 is the corresponding threshold limit…).

A.  Exposure Criteria for Occupational Exposure to Airborne Chemical
Substances

The OELs for the five primary contaminants of interest, in micrograms
per cubic meter (µg/m3), are summarized and additional information
related to those exposure limits is presented below.

Occupational Exposure Limits for Five Metals of Primary Interest
(µg/m3)

	Ba	Be	Cd	Pb	Ni

PEL	500 TWA	2 TWA

5 (30 minute ceiling)

25 (peak exposure never to be exceeded)	5 TWA	50 TWA	1000 TWA

REL	500 TWA	0.5 TWA	Lowest Feasible Concentration	50 TWA	15 TWA

TLV	500 TWA	2 TWA

10 (STEL)	10 (total) TWA

2 (respirable) TWA	50 TWA	1500 TWA (elemental)

100 TWA (soluble inorganic compounds)

200 TWA (insoluble inorganic compounds



This subset of five metals has been selected for consideration through
the body of this report because their presence was noted on MSDSs or
other information pertaining to CRTs and other processes at this
facility (Be, Cd, Pb and Ni) or due to the interest expressed in Ba
exposures by FOH personnel.

The occupational exposure limits of all 31 metals quantified in this
work are listed in Appendix A.  Note that these limits refer to the
contaminant as the element (e.g., the TLV®s, Be and compounds, as Be;
Cd and compounds, as Cd [ACGIH 2008]).  Additionally, the OEL for dust
is presented here to place those air sampling results in perspective.

Occupational Exposure Criteria for Ba

The current OSHA PEL, NIOSH REL, and ACGIH® TLV® is 0.5 mg/m3 as a TWA
for airborne Ba exposures (Ba and soluble compounds, except Ba sulfate,
as Ba) [29 CFR 1910.1000, NIOSH 2005, ACGIH 2008].  There is no AIHA
WEEL for Ba [AIHA 2007].  Skin contact with Ba, and many of its
compounds, may cause local irritation to the eyes, nose, throat and
skin, and may cause dryness and cracking of the skin and skin burns
after prolonged contact [Nordberg 1998].   

Occupational Exposure Criteria for Be

 to 0.05 μg/m3 TWA and 0.2 μg/m3 STEL based upon studies investigating
both chronic beryllium disease and beryllium sensitization [ACGIH 2008].
 There is no AIHA WEEL for Be [AIHA 2007].  Be has been designated a
known human carcinogen by the International Agency for Research on
Cancer [IARC 1993]. 

Occupational Exposure Criteria for Cd

dU), and Beta-2-microglobulin in urine (β2-M) [29 CFR 1910.1027
Appendix A]. An employee whose biological testing results during both
the initial and follow-up medical examination are elevated above the
following trigger levels must be medically removed from exposure to Cd
at or above the action level: (1) CdU level: above 7 μg/g creatinine,
or (2) CdB level: above 10 μg/liter of whole blood, or (3) β2-M level:
above 750 μg/g creatinine and (a) CdU exceeds 3 μg/g creatinine or (b)
CdB exceeds 5 μg/liter of whole blood [OSHA 2004].

The ACGIH® TLV® for Cd and compounds as Cd is 10 μg/m3  as a TWA, and
2 μg/m3 TWA for the respirable fraction of airborne Cd and compounds,
as Cd  [ACGIH 2008].  The ACGIH® also published a Biological Exposure
Index® that recommends that Cd blood level be controlled at or below 5
μg/L and urine level to be below 5 μg/g creatinine [ACGIH 2008]. 
There is no AIHA WEEL for Cd [AIHA 2007].

In 1976, NIOSH recommended that exposures to Cd in any form should not
exceed a concentration greater than 40 μg/m3 as a 10-hour TWA or a
concentration greater than 200 μg/m3 for any 15-minute period, in order
to protect workers against kidney damage and lung disease.  In 1984,
NIOSH issued a Current Intelligence Bulletin, which recommended that Cd
and its compounds be regarded as potential occupational carcinogens
based upon evidence of lung cancer among a cohort of workers exposed in
a smelter [NIOSH 1984].  NIOSH recommends that exposures be reduced to
the lowest feasible concentration [NIOSH 2005].  This NIOSH REL was
developed using a previous NIOSH policy for carcinogens (29 CFR
1990.103). The current NIOSH policy for carcinogens was adopted in
September 1995. Under the previous policy, NIOSH usually recommended
that exposures to carcinogens be limited to the “lowest feasible
concentration,” which was a non-quantitative value. Under the previous
policy, most quantitative RELs for carcinogens were set at the limit of
detection (LOD) achievable when the REL was originally established. 
From a practical standpoint, NIOSH testimony provided in 1990 on
OSHA’s proposed rule on occupational exposure to Cd noted that,
“NIOSH research suggests that the use of innovative engineering and
work practice controls in new facilities or operations can effectively
contain Cd to a level of 1 μg/m3.  Also, most existing facilities or
operations can be retrofitted to contain cadmium to a level of 5 μg/m3
through engineering and work practice controls” [NIOSH 1990].  

Early symptoms of Cd exposure may include mild irritation of the upper
respiratory tract, a sensation of constriction of the throat, a metallic
taste and/or cough. Short-term exposure effects of Cd inhalation include
cough, chest pain, sweating, chills, shortness of breath, and weakness. 
Short-term exposure effects of ingestion may include nausea, vomiting,
diarrhea, and abdominal cramps [NIOSH 1989].  Long-term exposure effects
of Cd may include loss of the sense of smell, ulceration of the nose,
emphysema, kidney damage, mild anemia, an increased risk of cancer of
the lung, and possibly of the prostate [NIOSH 1989, Thun et al. 1991,
Goyer 1991]. 

Occupational Exposure Criteria for Pb

 as an 8-hour TWA, with worker BLLs to be controlled to ≤ 30 µg/dL. A
national health goal is to eliminate all occupational exposures that
result in BLLs >25 µg/dL [DHHS 2000].  There is no AIHA WEEL for Pb
[AIHA 2007].

Occupational exposure to Pb occurs via inhalation of Pb-containing dust
and fume and ingestion from contact with Pb-contaminated surfaces.
Symptoms of Pb poisoning include weakness, excessive tiredness,
irritability, constipation, anorexia, abdominal discomfort (colic), fine
tremors, and "wrist drop” [Saryan and Zenz 1994, Landrigan et al.
1985, Proctor et al. 1991a].  Overexposure to Pb may also result in
damage to the kidneys, anemia, high blood pressure, impotence, and
infertility and reduced sex drive in both genders. In most cases, an
individual's BLL is a good indication of recent exposure to and current
absorption of Pb [NIOSH 1978].

Occupational Exposure Criteria for Ni

The NIOSH REL for Ni metal and other compounds (as Ni) is 15 µg/m3
based on its designation as a potential occupational carcinogen [NIOSH
2005].  The ACGIH® TLV® for insoluble inorganic compounds of Ni is 200
µg/m3 (inhalable fraction).  For soluble inorganic Ni compounds the
TLV® is 100 µg/m3 (inhalable fraction). The TLV® for elemental Ni is
1,500 µg/m3 (inhalable fraction) [ACGIH 2008]. The OSHA PEL for Ni is
1,000 µg/m3   TWA [29 CFR 1910.1000].  Metallic Ni compounds cause
allergic contact dermatitis [Proctor et al. 1991b].  NIOSH considers Ni
a potential occupational carcinogen [NIOSH 2005].  There is no AIHA WEEL
for Ni [AIHA 2007].

Occupational Exposure Criteria for Airborne Particulate

The maximum allowable exposure to airborne particulate not otherwise
regulated is established by OSHA at 15 mg/m3   for total and 5 mg/m3 
for the respirable portion [29 CFR 1910.1000].  A more stringent
recommendation of 10 mg/m3 inhalable and 3 mg/m3 respirable is presented
by the ACGIH® which feels that “even biologically inert insoluble or
poorly soluble particulate may have adverse health effects” [ACGIH
2008].  There is no AIHA WEEL for these substances [AIHA 2007].

B. Surface Contamination Criteria 

Occupational exposure criteria have been discussed above for airborne
concentrations of several metals.  Surface wipe samples can provide
useful information in two circumstances; first, when settled dust on a
surface can contaminate the hands and then be ingested when transferred
from hand to mouth; and second, if the surface contaminant can be
absorbed through the skin and the skin is in frequent contact with the
surface [Caplan 1993].  While the OSHA lead standard mandates that
surfaces be maintained as free of lead as practicable, there is
currently no surface contamination criteria included in OSHA standards
[OSHA 2008].  The health hazard from these regulated substances results
principally from their inhalation and to a smaller extent from their
ingestion; those substances are by and large “negligibly” absorbed
through the skin [Caplan 1993].  NIOSH RELs do not address surface
contamination either, nor do ACGIH TLVs or AIHA WEELs.  Caplan [1993]
stated that “There is no general quantitative relationship between
surface contamination and air concentrations...” He also noted that,
“Wipe samples can serve a purpose in determining if surfaces are as
‘clean as practicable’.  Ordinary cleanliness would represent
totally insignificant inhalation dose; criteria should be based on
surface contamination remaining after ordinarily thorough cleaning
appropriate for the contaminant and the surface.”  With those caveats
in mind, the following paragraphs present guidelines that help to place
the results of the surface sampling conducted at this facility in
perspective. 

Surface Contamination Criteria for Five Metals of Primary Interest

Surface Contamination Criteria for Pb

Federal standards have not been adopted that identify an exposure limit
for Pb contamination of surfaces in the industrial workplace.  However,
in a letter dated January 13, 2003 [Fairfax 2003], OSHA’s Directorate
of Compliance Programs indicated that the requirements of OSHA’s
standard for Pb in the construction workplace [29 CFR 1926.62(h)(1),
1926.62(i)(2)(i) and 1926(i)(4)(ii)] interpreted the level of
Pb-contaminated dust allowable on workplace surfaces as follows:  a) All
surfaces shall be maintained as ‘free as practicable’ of
accumulations of Pb, b) The employer shall provide clean change areas
for employees whose airborne exposure to Pb is above the permissible
exposure limit, c) The employer shall assure that lunchroom facilities
or eating areas are as free as practicable from Pb contamination, d) The
OSHA Compliance Directive for the Interim Standard for Lead in
Construction, CPL 2-2.58 recommends the use of HUD's acceptable
decontamination level of 200 µg/ft2 (21.5 µg/100 cm2) for floors in
evaluating the cleanliness of change areas, storage facilities, and
lunchrooms/eating areas, e) In situations where employees are in direct
contact with Pb-contaminated surfaces, such as, working surfaces or
floors in change rooms, storage facilities, lunchroom and eating
facilities, OSHA has stated that the Agency would not expect surfaces to
be any cleaner than the 200 µg/ft2 level, and f) For other surfaces,
OSHA has indicated that no specific level can be set to define how
"clean is clean" nor what level of Pb contamination meets the definition
of "practicable." OSHA notes that “the term ‘practicable’ was used
in the standard, as each workplace will have to address different
challenges to ensure that Pb-surface contamination is kept to a minimum.
 It is OSHA’s view that a housekeeping program which is as rigorous as
‘practicable’ is necessary in many jobs to keep airborne Pb levels
below permissible exposure conditions at a particular site” [Fairfax
2003]. Specifically addressing contaminated surfaces on rafters, OSHA
has indicated that they must be cleaned (or alternative methods used
such as sealing the Pb in place), as necessary to mitigate Pb exposures.
OSHA has indicated that the intent of this provision is to ensure that
employers regularly clean and conduct housekeeping activities to prevent
avoidable Pb exposure, such as would potentially be caused by
re-entrained Pb dust. Overall, the intent of the
"as-free-as-practicable" requirement is to ensure that accumulation of
Pb dust does not become a source of employee Pb exposures. OSHA has
stated that any method that achieves this end is acceptable. 

In the United States, standards for final clearance following Pb
abatement were established for public housing and facilities related to
children. However, no criteria have been recommended for other types of
buildings, such as commercial facilities.  One author has suggested
criteria based upon Pb-loading values. Lange [2001] proposed a clearance
level of 1000 µg/ft2 for floors of non-Pb free buildings and 1100
µg/ft2 for Pb-free buildings, and states that “no increase in BLL
should occur for adults associated or exposed within a commercial
structure” at the latter level.  These proposed clearance levels are
based on calculations that make a number of intentionally conservative
assumptions such as: a) Pb uptake following ingestion is 35% absorption
of Pb in the gastrointestinal system, b) Fingers have a total
“touch” area of 10 cm2 and 100% of the entire presumed Pb content on
all 10 fingers is taken up, c) The average ‘normal’ environmental Pb
dose (from ‘uncontaminated food/water/air) is 20 µg per day, d) The
weight of the exposed person is 70 kg, and e) Daily Pb excretion is
limited to an average of 48 µg.  Lange [2001] notes that “use of the
proposed values would provide a standard for non-child-related premises
(e.g. commercial, industrial, office)…” but cautions that,
“Further investigation is warranted to evaluate exposure and
subsequent dose to adults from surface lead.”

Surface Contamination Criteria for Be

ed 3 μg/100 cm2 during non-operational periods. The DOE also has
release criteria that must be met before Be-contaminated equipment or
other items can be released to the general public or released for use in
a non-Be area of a DOE facility.  These criteria state that the
removable contamination level of equipment or item surfaces does not
exceed the higher of 0.2 μg/100 cm2 or the level of Be in the soil in
the area of release.  Removable contamination is defined as “beryllium
contamination that can be removed from surfaces by nondestructive means,
such as casual contact, wiping, brushing, or washing.”

Surface Contamination Criteria for Cd

Like Pb and Be, Cd poses serious health risks from exposure.  Cd is a
known carcinogen, is very toxic to the kidneys, and can also cause
depression.   However, OSHA, NIOSH, AIHA and ACGIH® have not
recommended criteria for use in evaluating wipe samples.  The OSHA Cd
standard [29 CFR 1910.1027] mandates that “All surfaces shall be
maintained as free as practicable of accumulations of cadmium,” that,
“all spills and sudden releases of material containing cadmium shall
be cleaned up as soon as possible,” and that, “surfaces contaminated
with cadmium shall, wherever possible, be cleaned by vacuuming or other
methods that minimize the likelihood of cadmium becoming airborne.”  

Surface Contamination Criteria for Ni

NIOSH, OSHA, AIHA and ACGIH® have not established occupational exposure
limits for Ni on surfaces.

Surface Contamination Criteria for Ba

NIOSH, OSHA, AIHA and ACGIH® have not established occupational exposure
limits for Ba on surfaces.

C.  Noise Exposure Criteria

The OSHA standard for occupational exposure to noise [29 CFR 1910.95]
specifies a maximum PEL of 90 dB(A) for a duration of 8 hours per day. 
The regulation, in calculating the PEL, uses a 5 dB time/intensity
trading relationship, or exchange rate.  This means that a person may be
exposed to noise levels of 95 dB(A) for no more than 4 hours, to 100
dB(A) for 2 hours, etc.  Conversely, up to 16 hours exposure to 85 dB(A)
is allowed by this exchange rate.  NIOSH, in its Criteria for a
Recommended Standard, proposed an REL of 85 dB(A) for 8 hours, 5 dB less
than the OSHA standard [NIOSH 1972].  The NIOSH 1972 criteria document
also used a 5 dB time/intensity trading relationship in calculating
exposure limits.  However, the 1998 revised criteria recommends a 3 dB
exchange rate, noting that it is more firmly supported by scientific
evidence [NIOSH 1998].  The ACGIH® also changed its TLV® in 1994 to a
more protective 85 dB(A) for an 8-hour exposure, with the stipulation
that a 3 dB exchange rate be used to calculate time-varying noise
exposures.  Thus, a worker can be exposed to 85 dB(A) for 8 hours, but
to no more than 88 dB(A) for 4 hours or 91 dB(A) for 2 hours.

In 1983, a hearing conservation amendment to the OSHA noise standard
took effect [29 CFR 1910.95(c)] that requires employers to “administer
a continuing, effective hearing conservation program” whenever
employee noise exposures equal or exceed an 8-hour TWA of 85 dBA or,
equivalently, a dose of fifty percent.  The requirements include noise
monitoring, audiometric testing, providing hearing protectors, training
workers, and recordkeeping.

RESULTS AND DISCUSSION

The work described here was conducted in January, 2008 at the USP
Lewisburg, UNICOR recycling factory electronic components recycling
operations.  During this testing air, surface wipe, and noise data were
collected in locations where the electronics recycling operations were
taking place and measurements were made relating to air flow of the
local exhaust ventilation system.  The primary purposes of this
evaluation were to estimate the potential exposures of inmates and staff
to toxic substances and noise encountered during the recycling of
electronic components and to recommend remedial measures to reduce
exposures if necessary.

A statistical summary of air sampling results is presented in Table 1. 
Results of personal breathing zone and area air sampling are shown in
Table 2 for total particulate and Table 3 for particulate <10 m
diameter.  Surface wipe sample results are contained in Table 4; noise
measurements are shown in Table 5.  As mentioned in Section III above,
all samples were analyzed for 31 metals due to the parameters of the
analytical method.  While the data in these tables represent the results
of just the five metals of primary interest in this evaluation, results
of all analyses are contained in the appendices.   All data indicate
levels well below the OELs, even when results for combined exposures as
calculated by Equation 1 are considered, although the detection limit
for arsenic was not low enough for comparison to the most stringent OEL.
  Because arsenic was not found in any wipe or bulk samples either, it
was not considered a potential hazard at this facility.

A.   Air Sample Results

m diameter are presented in Table 3, with the full data set of all 31
metals in Appendix C.  

These data indicate low levels of airborne particulate and metals. 
Thirty-four samples were taken during normal production during the
January, 2008 study.  These data can be identified by date in Tables 2
and 3, but the magnitudes of the exposures were not generally different
by date.  Measurements during routine operations revealed that Ba
concentrations ranged between <0.05 and 2 μg/m3 and were unremarkable. 
Be levels also were all below the limit of detection, which varied with
sample volume, most being <0.006 μg/m3.  Cd, Pb and Ni, likewise, were
found at low levels ranging up to 0.1, 4, and 0.8 μg/m3, respectively. 
Pb was the metal found in highest quantity, with 13 of 21 samples above
the limit of detection and the highest concentration was approximately
10% of the occupational exposure limits.  Airborne total particulate
concentrations ranged to 650 μg/m3 (0.1 to 0.7 mg/m3).  No distinction
could be made between samples from different locations within the UNICOR
factory or between different jobs, primarily due to the high variability
in measured contaminant.  Sample durations ranged from approximately 2.5
to 7 hours.

The filter change operation in the glass breaking area, discussed in the
Process Description (Section II), was the task of most concern regarding
exposures of workers to toxic metals.  Visual observations did not
indicate high levels of airborne dust, and measurements of metals and
particulate confirmed these observations.  No airborne levels of any
metals were found in excess of the most stringent occupational exposure
criteria.  Ba ranged from <0.07 to 2 μg/m3.  No Be was detected (LOD of
0.03 μg/m3).  Cd ranged from <0.06 to 3 μg/m3 with no Cd detected in
respirable samples.  Again, Pb was the metal in highest concentration
ranging from <0.3 to 10 μg/m3.  All air samples collected during the
filter change were approximately 1.5 hours duration.

Airborne total particulate measurements ranged generally between 300 and
650 μg/m3, with one sample collected during the filter change operation
of 1,100 μg/m3.  Respirable particulate ranged from 30 to 290 μg/m3. 
While no statistical comparison was made because of the dissimilarity of
the sample conditions, a day-by-day comparison of total and respirable
particulate and Pb (from Tables 2 and 3 respectively) would suggest that
a large portion of the airborne particulate and metals was in the
respirable range.  

It should be reiterated here that no shredding or melting of components
was done at Lewisburg and these processes would be expected to produce a
greater potential for exposures to metals than the disassembly
processes.

B.  Surface Wipe Sample Results 

The surface wipe sample results collected during the visit in the
electronic recycling operations at the USP Lewisburg are summarized
below and in Table 4 for the metals of interest, and the entire surface
wipe sample data set is contained in Appendix D.  Results of
spectrofluorometric analysis for Be only confirmed ICP measurements and
are not repeated in the tables.

g/sq ft is a useful target value for judging the effectiveness of a
cleanup operation.  While there are no criteria for evaluating Cd
surface contamination, the highest Cd measurement was less than 10% of
the recommended Pb level (200 g/sq ft) which arguably could be used
as a target for measuring clean-up effectiveness.  Ni surface
contamination was less than 70 g/sq ft in all samples.

C.  Sound Level Measurements 

The data collected with noise dosimeters is presented in Table 5 for the
16 sets of data collected.  Four area samples were collected in the
glass breaking operation and 12 samples were collected in other
locations in the factory.  For each day of sampling, each sample is
described, and the start and stop times are presented along with the
sample duration (run time).  Following that, the mean sound pressure
level for the duration of the run (TEST AVERAGE DB) and the time
weighted average sound pressure level for an eight hour day (TWA DB) is
shown.  Sound pressure levels are in dB, A weighted, slow response and
presented for both the OSHA and NIOSH criteria.  Time weighted
calculations assume no exposure during the un-sampled time which for 15
of 16 samples was from 1 to 2 hours.  Several of the noise samples
exceeded the REL and TLV of 85 dBA and are highlighted in bold print in
Table 5.

 

While the REL and TLV are more conservative criteria for protecting
workers from over exposure to noise, the OSHA noise standard [29 CFR
1910.95] is legally enforceable.  This standard instructs the employer
to calculate the allowable noise dose from more than one sample as
follows: 

 

When the daily noise exposure is composed of two or more periods of
noise exposure of different levels, their combined effect should be
considered, rather than the individual effect of each. If the sum of the
following fractions: C(1)/T(1) + C(2)/T(2) C(n)/T(n) exceeds unity,
then, the mixed exposure should be considered to exceed the limit value.
Cn indicates the total time of exposure at a specified noise level, and
Tn indicates the total time of exposure permitted at that level. 

 

This means that, using the OSHA exchange values, none of the samples
collected on these two days exceeded the allowable dose to document an
overexposure to the PEL of 90 dBA, although measurements above 85 dBA
(OSHA criteria) are considered to be an action level which triggers the
requirement for a hearing conservation program. 

The maximum 8-hour TWA noise measurement during the Lewisburg evaluation
was 88 dBA (sample LST-03) on top of the glass breaking booth.  The
highest personal exposures were the bailers (samples LSW-01 and -05)
which were 85 and 84 dBA 8-hour TWA.

 

D.   Local Exhaust System Measurements 

The HFMs were designed and manufactured by Atmos-Tech Industries (model
HFM24-ST/RF/SP, Ocean City, NJ).  Each unit is equipped with a bank of
35% efficient pleated pre-filters and a HEPA filter, a direct-drive 1200
cfm fan with a ½ horsepower motor, and a control panel with a minihelic
pressure gauge and variable speed control.  Air enters through the
pre-filters in the front of the unit, passes through the HEPA filter,
and is discharged into the room through a grille at the back of the
unit.  A frame attached to the front of each unit supports 24-in long
plastic strip curtains on the front and sides.  The top is enclosed with
a sheet of ¼-inch clear polycarbonate plastic.  The pre-filters are
held in place by a metal grille.  Glass breaking is performed on top of
an angle-iron grate inside the area enclosed by the strip curtains. 
Both HFMs are in an area enclosed by a building wall on 3 sides and a
curtain composed of plastic strips on the other.   Figure IV shows the
right HFM, number 1.  

The average face velocity measured at HFM-1 (the one on the right when
facing them from the front) was 160 feet/minute (fpm), range 150 to 170
fpm; the average air velocity at the side was 140 fpm, range 130 to 150
fpm.  The average face velocity measured at HFM-2 was 140 fpm, range 130
to 150 fpm; the average air velocity at the side was 120 fpm, range 110
to 130 fpm.  

Because the HFMs discharge into the GBO enclosure (rather than to the
outside of the building, for example) and re-circulate the filtered air,
the enclosure is not under negative pressure with regard to the rest of
the glass breaking booth.  Recirculation of air from industrial exhaust
systems into workroom air can result in hazardous air contaminant
concentrations in the facility if not designed properly [ANSI/AIHA
2007].   The evaluation of this process indicates that the recirculation
as it occurred causes no increased exposures to workers in the glass
breaking booth.  If exhausting to the outside, any ventilation system
must be designed to meet applicable fire, safety, or environmental codes
that apply to this facility and operations

To provide air circulation between the glass breaking booth and the
general workplace, two exhaust fans were placed in the ceiling of the
glass breaking booth (which is approximately 5 feet below the ceiling of
the general workplace) to move air from the booth, through filters, into
the general work area.  The assumption was that air would be pulled from
the general work area, through the plastic strip curtains forming the
front wall of the glass breaking booth (not visible in Figure IV) or
other openings.  Smoke released at the plastic curtain showed little air
flow into the enclosed area indicating that those two exhaust fans
placed on top of the glass breaking enclosure were not sufficient to
produce significant flow across the pressure drop caused by the plastic
curtain.

VI.  CONCLUSIONS AND RECOMMENDATIONS

The primary purpose of sampling is to determine the extent of employee
exposures and the adequacy of protection.  Sampling also permits the
employer to evaluate the effectiveness of engineering and work practice
controls and informs the employer whether additional controls need to be
installed.  Values that exceed OELs indicate that additional controls
are necessary.  This study focused on the evaluation of airborne
exposures and noise, with additional data collected on surface
contamination.  The results of air sampling during this January 2008
survey found that Pb, Cd, and other metals are generated and released
during the recycling operations at this facility.  No exposures to
airborne metals or particulate were found that exceeded the OSHA Action
Level for these substances during normal production or during the
monthly filter change operation.  Recommendations are presented below to
assure the continued safe conditions at Lewisburg Federal Correctional
facility.  

Although there was initial concern about Be and literature that pertains
to e-waste recycling report that Be is present in electronic components,
none was detected in air or wipe samples collected at this facility. 
One explanation for this is based on the work of Willis and Florig
[2002].  They note that Be “in consumer products is used in ways that
are not likely to create beryllium exposures during use and
maintenance.”  The recycling operations (except the glass breaking
operation) involve disassembly of electronics and sorting of the
components.  While some breakage occurs during the disassembly process,
the components likely to contain Be are not subject to further
processing that might create the potential for Be exposures. 

Of the UNICOR recycling facilities evaluated to date, Lewisburg has the
most adequate arrangement for donning and doffing personal protective
clothing and equipment.  While some situations require showers as a part
of the decontamination process, this is not considered necessary for the
work conducted at Lewisburg since the levels of contaminant are low. 
The arrangement in its present configuration is deemed adequate. 
Assurance needs to be made, however, that respirators and clean
protective clothing are stored in lockers in the work area, where they
are not at risk of contamination.

While the recommendations presented here address certain areas and
issues observed during this evaluation, there needs to be a
site-specific health and safety program at Lewisburg.  Based on the data
presented above, the following recommendations are made.  These
recommendations are divided into 3 categories, described as programmatic
issues, procedural issues, and housekeeping issues.    

Programmatic issues:

The respiratory protection program for this facility should be evaluated
for this operation in order to ensure that it complies with OSHA
regulation 1910.134.  

A hearing protection program should be implemented and compliance with
all provisions of the OSHA standard for occupational exposure to noise
[29 CFR 1910.95] should be verified.

Training of workers should be scheduled and documented in the use of
techniques for dust suppression, the proper use of local ventilation,
personal protection equipment (e.g., coveralls, respirators, gloves) and
hazard communication.

Frequently while conducting the on-site work, NIOSH researchers observed
tasks being conducted in a manner that appeared to be very awkward. 
Tasks should be evaluated to determine if there are excesses in
repetitive stress trauma and if modifications in procedures or equipment
would provide benefit to this workplace.

Heat stress should be periodically evaluated during hot weather (e.g.,
the summer months).  

All UNICOR operations, including but not limited to recycling should be
evaluated from the perspective of health, safety and the environment in
the near future. 

A program should be established within the Bureau of Prisons to assure
that these issues are adequately addressed by competent, trained and
certified individuals.  While a written program to address these issues
is necessary at each facility, adequate staffing with safety and health
professionals is required to ensure its implementation.  One indication
of adequate staffing is provided by the United States Navy, which states
“Regions/Activities with more than 400 employees shall assign, at a
minimum, a full time safety manager and adequate clerical support”
[USN 2005].  That document also provides recommended hazard-based
staffing levels for calculating the “number of professional personnel
needed to perform minimum functions in the safety organization.”

A comprehensive program is needed within the Bureau which provides
sufficient resources, including professional assistance, to assure each
facility the assets needed to assure both staff and inmates a safe and
healthy workplace.

Procedural issues:

The use of an alternative method (e.g., static pressure drop) should be
investigated to determine frequency of filter change.  The manufacturer
of this system may have guidelines in this regard.

Workers performing the filter change operation should continue to
utilize respiratory protection as part of a comprehensive respiratory
protection program. The PAPRs used provide adequate protection for the
filter change operation.

Because the facility already provides uniforms to its workers,
management should evaluate the feasibility of providing and laundering
work clothing for all workers in the recycling facility, instead of the
current practice of providing disposable clothing for glass breaking
workers only.  Contaminated work clothing must be segregated from other
clothes and laundered in accordance with applicable regulations.

The use of alternative methods to break cathode-ray tubes should be
investigated by Lewisburg management to determine if further
improvements are feasible.  Lee et al. [2004] present different methods
to separate panel glass from funnel glass in CRT recycling (sec 2.1) and
for removing the coatings from the glass (sec 2.2).  The hot wire and
vacuum suction methods (supplemented with local exhaust ventilation)
described by Lee et al. may produce fewer airborne particulates than
breaking the glass with a hammer. The authors [Lee et al. 2004] describe
a commercially-available method in which an electrically-heated wire is
either manually or automatically wound around the junction of the panel
and funnel glass, heating the glass.  After heating the glass for the
necessary time, cool (e.g., room temperature) air is directed at the
surface, fracturing the glass-to-glass junction using thermal shock. 
The separated panel and funnel glass can then be sorted by hand.  They
also describe a method wherein a vacuum-suction device is moved over the
inner surface of the panel glass to remove the loose fluorescent coating
[Lee et al. 2004].  The vacuum used must be equipped with HEPA
filtration.  Industrial central vacuum systems are available; they may
cost less in the long run than portable HEPA vacuum cleaners. These
modifications may also reduce the noise exposure to glass breakers. 

Because of the noise levels found in the glass breaking operation,
engineering controls should be designed or selected using noise
reduction as a criterion.  Until noise in the glass breaking operation
can be reduced through engineering controls, a hearing conservation
program including noise monitoring, audiometric testing, providing
hearing protectors, training workers, and recordkeeping must be
implemented for workers in the glass breaking operation.

Housekeeping:

Due to the levels of surface contamination of Pb measured in the
recycling facility, workers should wash their hands before eating,
drinking, or smoking.

Given the concentrations of Pb and Cd detected in the surface wipe
samples and air measurements, periodic industrial hygiene evaluations
and facility inspections are recommended to confirm that exposures are
maintained below applicable occupational exposure limits. 

Daily and weekly cleaning of work areas by HEPA-vacuuming and wet
mopping should be continued, taking care to assure no electrical or
other safety hazard is introduced.  The BG/BIA guidelines [2001]
recommend daily cleaning of tables and floors with a type-H vacuum
cleaner.  Type H is the European equivalent of a HEPA vacuum, where the
H class requires that the filter achieve 99.995% efficiency, where 90%
of the test particles are smaller than 1.0 um and pass the assembled
appliance test, 99.995% efficiency where 10% of the particles are
smaller than 1.0 um, 22% below 2.0 um, and 75% below 5.0 um. While some
surface contamination was measured in work areas, this would be much
greater if it were not for the good housekeeping practices in effect in
all locations observed.  Other practices not observed during the time of
this evaluation, but which have been observed at other facilities should
be discouraged; these include the use of compressed air to clean parts
or working surfaces, and the consumption of food, beverage or tobacco in
the workplace.

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Table 1  

Summary Statistics for Airborne Metal Measurements*

Collected at USP Lewisburg 

(Concentration unit for means is µg/m3)

	Particulate	Ba  	Be  	Cd  	Pb  	Ni  

15 total particulate samples collected in recycling operations
(excluding GBO)

Ar. Mean	540	0.262	0.004	0.031	0.451	0.157

Ar. St. Dev	147	0.126	0.001	0.020	0.278	0.109

Geo Mean	521	0.235	0.003	0.024	0.380	0.130

GSD	1.378	1.630	1.254	2.315	1.836	1.824









5 total particulate samples collected in GBO, normal operation



Ar. Mean	463	1.117	0.003	0.077	2.427	0.322

Ar. St. Dev	221	0.642	0.001	0.039	1.479	0.140

Geo Mean	373	0.710	0.003	0.067	1.822	0.298

GSD	2.480	4.347	1.192	1.851	2.797	1.570









4 respirable samples collected in GBO, normal operation



Ar. Mean	95	0.232	0.003	0.030	0.518	0.137

Ar. St. Dev	49	0.166	0.000	0.000	0.180	0.082

Geo Mean	83	0.159	0.003	0.030	0.495	0.119

GSD	1.924	3.381	1.174	1.000	1.415	1.866









4 total particulate samples collected during filter change operation

	Ar. Mean	451	0.621	0.013	0.886	3.096	0.692

Ar. St. Dev	435	1.078	0.000	1.373	4.792	0.230

Geo Mean	340	0.149	0.013	0.376	1.370	0.653

GSD	2.240	7.120	1.000	4.099	3.833	1.519









4 respirable samples collected during filter change operation



Ar. Mean	163	0.248	0.010	0.110	0.856	0.349

Ar. St. Dev	90	0.247	0.002	0.020	0.587	0.125

Geo Mean	147	0.142	0.010	0.109	0.741	0.334

GSD	1.672	3.960	1.202	1.183	1.795	1.395



*Ar. Mean = arithmetic mean

 Ar. St Dev = arithmetic standard deviation 

 Geo Mean = geometric mean

 GSD = geometric standard deviation

 All “non-detected” samples were set at half the limit of detection
for statistical calculations.

( This report documents the study conducted at Lewisburg, Pennsylvania. 
Other NIOSH field studies were conducted at Federal correctional
facilities in Elkton, Ohio and Marianna, Florida 

 On March 20, 1991, the Supreme Court decided the case of International
Union, United Automobile, Aerospace & Agricultural Implement Workers of
America, UAW v. Johnson Controls, Inc., 111 S. Ct. 1196, 55 EPD 40,605. 
It held that Title VII forbids sex-specific fetal protection policies. 
Both men and women must be protected equally by the employer.

 OSHA PELs, unless otherwise noted, are TWA concentrations that must not
be exceeded during any 8-hour workshift of a 40-hour work-week [NIOSH
1997].  NIOSH RELs, unless otherwise noted, are TWA concentrations for
up to a 10-hour workday during a 40-hour workweek [NIOSH 1997].  ACGIH®
TLVs®, unless otherwise noted, are TWA concentrations for a
conventional 8-hour workday and 40-hour workweek [ACGIH 2008]

 OSHA has referenced a Department of Housing and Urban Development (HUD)
lead criteria in documents related to its enforcement of the lead
standard [Fairfax 2003].

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