TEM
March
5,
2003
The
Total
Exposure
Model
(
TEM)
is
a
combination
mechanistic
and
stochastic
model.
It
models
physical
and
chemical
processes
which
govern
the
transport
of
chemicals
from
tap
water
into
indoor
air
environments
(
e.
g.
showering,
clothes
washing,
dish
washing)
and
stochastically
models
the
related
human
activities
that
would
also
govern
the
ultimate
human
exposure.

Purpose:
TEM
predicts
the
exposure
and
dose
to
an
individual
resulting
from
use
of
a
contaminated
water
supply
by
modeling
the
fundamental
physical
and
chemical
processes
that
occur
during
the
interaction
between
the
contaminated
media
(
in
this
case,
the
air
and
water)
and
the
exposed
individuals.
Using
finite
difference
techniques,
TEM
estimates
the
mass
transfer
of
the
chemicals
from
the
water
to
the
air
during
water
use
activities.
TEM
predicts
the
resultant
water
concentrations
during
use
and
air
concentrations
throughout
the
house.
Using
these
predicted
air
and
water
concentrations
and
location
information
provided
by
field
studies,
TEM
estimates
potential
exposure
to
the
subject.
This
model
Contact:
Jerry
Blancato
(
702)
798­
2356
Las
Vegas;
(
919)
541­
3288
while
on
detail
to
RTP.

Short­
term
Followup:
Since
this
model
is
predominantly
designed
to
support
indoor
exposure
assessments
and
is
likely
to
require
more
data
than
is
typically
available
during
a
typical
environmental
assessment.
It
is
therefore
unlikely
to
prove
useful
in
the
planning
process.
Evaluate
the
Multimedia,
Multipathway
and
Multireceptor
Risk
Assessment
(
3MRA)
Model,
which
may
be
better
matches
for
the
304(
m)
planning
process.
Based
on
the
review
of
3MRA,
there
may
be
no
need
for
further
investigation
of
this
tool.
