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THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) STUDY IN ARIZONA-INTRODUCTION AND PRELIMINARY RESULTS
Citation:
Robertson, G L., M. D. Lebowitz, M. K. O'Rourke, S. M. Gordon, AND D. J. Moschandreas. THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) STUDY IN ARIZONA-INTRODUCTION AND PRELIMINARY RESULTS. JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY 9(5):427-434, (1999).
Impact/Purpose:
The overall objectives of this task are to
1) conduct analyses of the NHEXAS data for description of data quality and aggregate exposures;
2) review, summarize, and organize the NHEXAS questionnaire and analytical results databases, and
3) collect and record the experiences and recommendations of the study investigators and staff regarding key lessons which were learned in conducting these studies.
Description:
The objective of the National Human Exposure Assessment Survey (NHEXAS) in Arizona is to determine the multimedia distribution of total human exposure to environmental pollutants in the classes of metals, pesticides, and volatile organic compounds (VOCs) for the population of Arizona. This was accomplished by studying a probability-based sample of the total population in Arizona with a nested design for the different stages of sampling (954 Stage I, 505 Stage II, and 179 Stage III participants). This report compares the study population demographics with those from the U.S. Census and provides preliminary data on the distributions of the example pollutant for each class, lead for metals, chlorpyrifos for pesticides, and benzene for metals. The probability-based sample age and gender demographics compare reasonably well with the Census data (1990 Census and 1996 Census Estimate). The race/ethnicity compared less well with 21% Hispanics in the 1996 Census Estimate and 42% Hispanics in the entire NHEXAS-Arizona sample and 30% Hispanics as Stage III participants for this study. The chemical analyses of the various media (yard soil, foundation soil, house dust, indoor air, outdoor air, drinking water, food, and beverage) show generally low levels of the representative pollutants. The 50th percentiles of the distributions are generally near or below the analytical detection limits, and applicable Federal action limits were rarely exceeded.
Preparation of this document has been funded wholly or in part by the U.S. Environmental Protection Agency under cooperative agreement CR821560 to the University of Arizona. It has been subjected to agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.