To study the functional implications of genetic polymorphism or variation relative to specific environmental exposures and disease development, better exposure data will be required. However, little is known about actual human exposure and body burdens of environmental pollutants. This knowledge gap hampers regulatory decision making and introduces uncertainties in setting exposure limits. It also limits our understanding of dose-response relationships and capacity to develop effective prevention strategies. Exposure is typically estimated using indirect surrogates of environmental quality, such as toxic release and production inventories and environmental monitoring.
Actual exposure is highly variable for individuals and subpopulations.
It is really a function of individual uptake, metabolism, excretion and behavior. So the assumption that all men, women and children living in the same geographic area have similar exposure is seriously flawed. What we need are direct measures of exposure based on tissue analysis or deposition. These and future efforts are expected to strengthen what is often viewed as the weakest link in the risk assessment process. The effects of exposure are not just limited to individual chemicals.