Geography-Based Exposure Assessment for Urban Metals

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Although lead is a naturally occurring element present in many parts of the environment, human activities have dramatically increased lead levels in many locales, especially older parts of urban areas. Whereas lead normally constitutes about 0.002 percent of the Earth's crust, in cities, soil lead levels can be from five to 25 times as great. The heightened presence of lead translates into significantly increased exposure to lead contamination among urban residents, especially children. The average background lead level of the U.S. population is 2.8 micrograms per deciliter, but in many cities, substantial numbers of children have baseline blood lead levels in excess of 10 micrograms per deciliter. This research project will develop new methods for exploring spatial dimensions of pediatric lead poisoning. A multidisciplinary investigative team will study spatial relationships among urban environmental contaminants, the biogeochemical processes of their origin in soils and dust, and the potential for adverse public health risks associated with human exposure to them. A primary goal of this project is to quantitatively assess the community health risks associated with exposure to soils and interior household dusts that have been contaminated by heavy metals. A second major goal is to determine the feasibility of carrying out such assessments through the use of non-intrusive, ecological techniques. To accomplish these goals, the investigators will develop a geography-based lead-exposure assessment model for Syracuse, New York. Inputs to this model will be the blood lead monitoring results, population and housing census data, heavy-metal measurements for soils and dust, and other georeferenced data.This research will make a number of contributions to the spatial analysis literature. For example, it will extend small area estimation techniques to a nesting situation and establish a trade-off curve between effective sample size and accuracy/precision of sample statistics. It will improve understanding of geographic dimensions of lead dispersal, and it will test new approaches for monitoring contamination. This project also will have a significant policy impacts for the public health arena. In particular, it will provide a widely applicable, cost-effective, childhood lead poisoning assessment tool for urban environments; it will foster a geographically explicit interpretive framework for evaluating intervention measures; and it will help contribute to improvements in EPA exposure modeling capabilities.