"
Johnston,
A.
Todd"
<
ajohnston@
nma.
org>

07/
12/
2006
08:
27
PM
T
o
Jason
Burnett/
DC/
USEPA/
US@
EPA
c
c
S
u
b
j
e
c
t
comments
on
Veranth
Jason
­

We
had
Dr.
Jonathan
Borak
critique
one
study
that
was
reported
to
us
as
identified
in
an
interagency
briefing
as
supporting
the
proposition
that
rural
soils
are
as
toxic
and
harmful
as
urban
coarse
PM,
and
thus
a
reason
for
not
following
through
with
the
proposed
exclusion
for
mining
and
ag.
The
study
was
authored
by
Veranth
et
al.

His
two­
page
preliminary
analysis
is
attached.
Dr.
Borak
concludes
as
follows:

"
This
study
raises
interesting
hypotheses
that
deserve
study,
but
it
provides
no
specific
data
of
relevance
to
the
proposed
PM10­
2.5
NAAQS.
First,
there
is
no
general
property
of
particulate
­
coarse
or
fine
­
that
is
described
here.
Second,
it
is
unclear
whether
the
exposure
levels
are
biologically
relevant
to
ambient
exposures.
Third,
the
actual
exposures
involved
PM2.5,
not
coarse
particulate."

We
are
in
the
process
of
looking
at
several
other
studies
identified
in
various
comments
that
purport
to
show
a
link
between
rural
coarse
PM
and
health
effects
and
will
forward
the
results
as
they
become
available.

If
there
are
any
other
studies
that
have
been
identified
as
of
concern,
please
let
us
know
and
we'll
have
Dr.
Borak
tale
a
look
at
them
as
well.
Todd
Johnston
National
Mining
Association
202­
463­
2668
