Breathing Zone Exposure Assessment - Aerosols: Measurement, Dosimetry, and Health Effects - page 42

TABLE 2.3
Active (Pumped) Personal Exposure Sampling Approaches

Active
Sampling
Approaches

PEM inlet
Location

Participant
Burden Level

Pump Location Target Cohort Notes

BZ Within 0.3 m;

lapel, vest
pocket,
shoulder strap

Integrated BZ
package, waist
pack, backpack

Medium to
high

Healthy adults
only if high
burden;
compromised
adults and older
children if
minimally
intrusive

“Gold standard”
approach

Waist pack Front of pack,

waist level

Inside waist
pack

Medium Healthy adults,

compromised
adults and
children

Okay for ine particles;
coarse particles may
be biased by “ground
cloud”

Backpack Side of

backpack, or
connected
across shoulder
to lapel

Inside backpack Medium Younger children

or for excessively
heavy monitors

May interfere with
children's topic bags;
excessive burden may
result in low wearing
compliance

Pull cart Pull cart handle Pull cart

platform

Low to
medium

Compromised
adults; elderly

May be biased by
“ground cloud”

Surrogate
person

On trailing/
nearby person

On trailing/
nearby person

Minimal Adults or children

that are burden
averse

Surrogate labor time
and cost; not
representative of
individual ground
cloud

Predictive
exposure
models

None required None required None Selected cohorts;

metro populations

Utilizes ambient
monitoring and
estimates of times
spent indoors and
outdoors; poorly
estimates the most
exposed

methodologies for gases, aerosols, and radiation are summarized in Table 2.3. The collection of
personal exposure samples for gases and vapors, including those directly from the BZ, is described
by Brown and Monteith (2001), including an array of active (pumped) and passive techniques. The
active techniques require the air sample to be drawn through miniature absorber tubes clipped to
the lapel containing speciic substrates (e.g., charcoal, XAD-2) by a controlled low rate pump. The
pump is often attached to the waist. Low-burden passive badge samplers are also described that
attach to the lapel for a wide range of contaminants including organic vapor, amines, aldehydes,
ozone, nitrogen dioxide, and mercury.
Particle phase contaminants are almost universally sampled in an active mode, but typically
require an aerodynamic sizing step that signiicantly increases the size and complexity of the inlet.
Often the resulting device is simply too cumbersome to attach directly to a lapel. The air stream
is irst sampled through a size-classifying device (e.g., cyclone, impactor) and the aerosol then col-
lected on either a ilter or media (e.g., impactor plate, agar [viable], or liquid [bubbler]). Hering