Identifying public health tools for environmental policy: A case study of cumulative risk assessment in south and southwest Philadelphia

Despite a common goal of improved public health, the US Environmental Protection Agency's (US EPA) use of quantitative risk assessment to measure and manage health risks differs from approaches used by the nation's public health agencies. These differences have contributed to fragmented responses to environmental health risks (Pew, 2000). This thesis examines cumulative risk assessment as the means to integrate public and environmental health activities. A review of literature identified the conceptual basis and practical need for this integration of approaches.; Cumulative risk assessment is well-defined conceptually but lacking methodologically. A multi-endpoint toxicological database containing information for about seven health endpoints per chemical was developed for the Clean Air Act Hazardous Air Pollutants (HAPs). This database was compared to US EPA's current database that contains reference values based on a single health endpoint per chemical of concern. The findings indicate that endocrine, immunological, and heart and blood effects may be overlooked in the regulatory process. Few HAPs have these endpoints as the “critical effect” using the current database.; The relevance of cumulative risk assessment as a public health tool was examined in a case study of South and Southwest Philadelphia neighborhoods. Rank order correlation and Poisson regression analyses were employed to test the hypothesis that cumulative risk scores would positively correlate with mortality rates at the neighborhood and census tract levels.; Positive correlations and statistically significant (p < 0.001) associations between cumulative risk and mortality rates were found for total mortality when the cumulative risk assessment was conducted with the multi-endpoint toxicological database. Statistically significant increases in respiratory mortality rates at the census tract level were associated with incremental increases in the respiratory risk score derived from the multi-endpoint database.; These findings validate the concepts of cumulative risk assessment and demonstrate that these methods apply at the community level. While efforts are needed to improve the toxicological reference database, cumulative risk assessment is a viable tool for risk screening to identify high-risk areas and guide research and intervention nationally and locally.