Environmental Stressor and Exposure
Information for Older Adults

Kent Thomas1, Stephanie Buehler2, Nancy Wilson2, Sydney Gordon2, James Raymer3, Larry Michael3, and William Studabaker3
l	1:U.S. EPA Office of Research and Development, National Exposure Research Laboratory, 2Battelle, 3RTI International	,

Introduction

l

Methods

	

Stressors with reported health outcome assessments in older populations or
subpopulations are summarized in Table 1.

For organophosp horns pesticides, pyrethroid pesticides, and persistent organohalo-
gens, nothing of specific relevance to the exposures and health within the aging
population was found. (The focus of this work was on exposures/outcomes for older
adults and not on effects fromearly or chronic lifetime exposures).

Selected results of literature searches for exposure information for key stressors
are summarized in Table 2.

Overall, environmental and personal exposure measurement results are sparse in
older populations for many environmental stressors.

Studies of exposures to environmental contaminants in populations that include
older adults often do not report separate results for younger and older segments of
the population.

Selected results from comparisons of NHANES and NHEXAS measurements
in older and younger age groups are shown in Figures 1-6. Geometric means
are shown in each figure. The p-values for tests of the significance of differences
between age groups are also reported.

Biologically persistent pollutant biomarkers were often found at higher levels in
older adults, for example lead and DDE in Figures 1 and 2. It is not clear if this is
a result of longer lifetime accumulations, exposures occurring when environmental
levels were higher, or a combination.

Biomarker concentrations for some non-persistent pollutants were lower in older
adults, for example metabolites of pyrene and diethylhexyl phthalate in Figures 3
and 4. This maybe related to reduced occupational exposure and/or lower activity
or product use levels.

More research is needed to understand whether differences in biomarker levels
are the result of differences in exposure or are related to changes in physiology.

T\vo examples of age-group differences in indoor air levels of particulate matter
and 1,1,1-trichloroethane in a NHEXAS study are shown in Figures 5 and 6. These
may be related to differences in activity and pro duct use, but further investigation
is needed.

Table 1. Selected Environmental Stressor and Health Information for Older Adults

Figure 1 Lead

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Figure 3 t-Hydroxypyrene

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Figure 5 Paniculate Matter {IQM)

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Figure 2. p,p'-DDE

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Table 2. Selected Exposure Information for Older Adults

Table 3. Research Needs To Reduce Uncertainties for Older Adults

Conclusions

I

general, exposure and health outcome information for older adults is lim:
¦r many environmental stressors, particularly with regard to potentially
insitive segments of the aging population.

Little research has been done on elderly populations' exposures from multiple
environmental media, to assess the aggregate and cumulative contributions from the
various media, and to evaluate the relative importance of the routes of exposure -
. inhalation, ingestion, and dermal absorption - and how their relative importance may
change as individuals age.

Studies that take into account the altered activity and lifestyle factors, altered
physiology, and different exposure potential of aging populations and sensitive
subpopulations are needed to reduce uncertainties in exposure and risk assessments.

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