POPULATION-BASED EXPOSURE MEASUREMENTS IN ARIZONA - A PHASE-I FIELD-STUDY IN SUPPORT OF THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY

The objective of this proposed Phase I field study is to determine the distributions of total human exposures to multimedia pollutants in th e classes of metals, pesticides, and volatile organic compounds (VOCs) . This will be achieved by studying a proportion-based sample of the t otal population in Arizona with a nested design for the different stag es of sampling. Specific objectives are: (1) to document the occurrenc e, distribution, and determinants of total exposures in the general po pulation; (2) to characterize the 90th percentiles of total exposures to each pollutant; (3) to monitor geographic and temporal trends of th e multimedia exposures; (4) to evaluate the different media, personal, time-activity, and geographical factors that contribute to current to tal exposure; (5) to evaluate biomarkers in blood and urine for the ta rget pollutants; (6) to perform evaluations of relationships between e xposure reports, environmental measurements, and biomarkers of the tar get pollutants; (7) to predict total exposures; and (8) to assess tota l exposures in minority and disadvantaged subsets of the population. T he latter is particularly feasible in Arizona due to the large proport ions of such population subgroups. The proportionate-based population sampling of households within blocks will occur in Stage 1; the target is 1,200 such households. They will be interviewed utilizing National Human Exposure Assessment Survey (NHEXAS) questionnaires. In Stage 2, additional questionnaires will be completed; environmental sampling w ill take place in 450-900 households representatively selected from th e respondents. Environmental sampling will include: metals in dust, so il, outside air, and some tap water; pesticides in dust, soil, and som e tap water; total VOCs in air. In Stage 3, a subset of representative households will be reevaluated for metals, pesticides, and VOCs using methods with greater resolution and reliability; subjects in these ho useholds will be asked to complete questionnaires and provide biologic al samples. Follow-up temporal evaluations will be performed in a rand omly selected subset of homes evaluated during this stage.