Strategic environmental assessment of community air toxics exposure resulting from land use policy.

摘要

A significant problem in metropolitan areas is chronic population exposure to very small amounts of toxic chemicals emitted to the atmosphere by industrial, commercial and transportation sources, resulting in increased risk of cancer and other noncarcinogenic health hazards. My research goal was an approach to integrating community health risk characterization into the land use planning process by linking risk simulation and land use optimization models in a spatial decision support system for the strategic environmental assessment and management of the long-term health risk impacts of air toxics exposure resulting from implementation of land use policies.; The key system component is a source model for estimating land use emission factors as a function of local policy for permitted uses. A case study is used to test system accuracy and its ability to estimate the potential impacts of long-range land use policy. Major components of the spatial decision support system are: (1) LUAIRTOX—a source model for estimating air toxics emission factors for land use zoning districts as a function of uses permitted by local ordinance; (2) ISCST3—the EPA's regulatory model for predicting fate and transport of airborne contaminants, which was adapted to use land use zoning districts as source terms; and (3) a linear programming model to manage community health risk by optimizing planned land use to minimize the total community risk burden. The system components are loosely coupled using a GIS for data management and results visualization.; The spatial decision support system is especially timely because of the growing interest by planning professionals and citizen groups in the concept of “new urbanism” or neo-traditional planning, which has not yet satisfactorily explained how to accommodate the manufacturing sector in a community. The case study results suggest that neo-traditional land use policies encouraging expansion of the manufacturing base from within or nearby existing residential neighborhoods may exacerbate the risk burden on those areas. The health risk implications of these policies need to be explored before adoption, and alternative land use strategies or risk management policies developed. This research provides a tool for air toxics risk assessment and risk management.