Evaluating cumulative risk assessment for environmental justice: A community case study

A key feature of cumulative risk assessment (CRA) is the ability to estimate differential health risks from environmental exposures within populations. Identifying populations at increased risk from environmental exposures is the first step toward mitigating such risks as required by the fair treatment mandate of environmental justice. CRA methods remain under development except for a limited application in pesticide regulations. The goals of this research were to advance CRA methods and to test their application in a community case study. We compared cumulative risk and health assessments for South and Southwest Philadelphia communities. The analysis found positive correlations between cumulative risk and mortality measurements for total mortality in Whites and non-Whites when we conducted the risk assessment using a multi-end point toxicological database developed for this project. Cumulative risk scores correlated positively with cause-specific mortality in non-Whites. Statistically significant increases in total and respiratory mortality rates were associated with incremental increases in the hazard ratio cumulative risk scores, with ranges of 2-6% for total and 8-23% for respiratory. Regression analyses controlled for percent non-White population and per capita income, indicating that risk scores represent an environmental effect on health independent of race and income. This case study demonstrated the successful application of CRA at the community level. CRA adds a health dimension to pollutant concentrations to produce a more comprehensive understanding of environmental inequities that can inform decision making. CRA is a viable tool to identify high-risk areas and to guide surveillance, research, or interventions.