Environmental Health Criteria 214

HUMAN EXPOSURE ASSESSMENT
local contaminant sources is typically collected via questionnaires
that ask whether or not the participant engaged in a certain activity.
For instance, studies of VOC exposure have asked about use of
household cleaners, visits to petrol stations and storage of gasoline
products indoors (Wallace et al., 1987a,b). Questionnaires are also
used to solicit information on housing unit characteristics (e.g.,
type of cooking equipment or house volume) that influence
concentrations indoors (Lebowitz et al., 1989). Surveys may request
information on a variety of parameters that affect the concentration
of combustion products to which an individual is exposed during
travel, including traffic speed, time of day, mode of transportation,
age of vehicle, trip timing and roadway used.
Researchers have experimented with a variety of methods for
collecting information on the intensity of contact. As described in
Chapter 7, a number of approaches are used for quantifying food
consumption rates. An inexpensive technique that has been used to link
breathing and activity patterns is to have participants record the
level of activity (e.g., high, medium, low) associated with each
activity entry in the diary. This method has been used in several
population-based studies (Johnson, 1989; Lichtenstein et al., 1989;
Schwab et al., 1990; Wiley et al., 1991). Others have used
questionnaires that request information about specific high-exertion
activities such as exercising and working outdoors (Goldstein et al.,
1986; Lebowitz et al., 1989). Categorical exertion-level data is not
useful for calibrating activity pattern data, however, without an
increased understanding of (1) the range of reported activities
associated with each exertion level and (2) the range of breathing
rates associated with each exertion level. A compendium on energy
expenditure, which closely relates to ventilation rate, has been
published for a variety of physical activities (Ainsworth et al.,
1993). These data may be used to categorize activity data depending on
levels of exertion (Künzli et al., 1997a,b). Data are becoming
available through the application of electronic methods of tracking
exertion levels; heart-rate and breathing-rate monitors have been used
in the field studies by Raizenne & Spengler (1989), Shamoo et al.
(1991) and Terblanche et al. (1991).
http://www.inchem.org/documents/ehc/ehc/ehc214.htm
Page 87 of 284
6/1/2007