Tracking health and the environment: a pilot test of environmental public health indicators

Examining the relationship between health outcomes and environmental exposures requires summary measures, or indicators. To advance the use of indicators, the Johns Hopkins Center for Excellence in Environmental Public Health Tracking piloted three pairs of indicators: 1) air toxics and leukemia in New Jersey, 2) mercury emissions and fish advisories in the United States, and 3) urban sprawl and obesity in New Jersey. These analyses illustrate the feasibility of creating environmental hazard, exposure, and health outcome indicators, examining their temporal and geographic trends, and identifying their temporal and geographic relationships. They also show the importance of including appropriate caveats with the findings. The authors' investigations demonstrate how existing environmental health data can be used to create meaningful indicator measures to further the understanding of environment-related diseases and to help prioritize and guide interventions. Indicators are the foundation of environmental public health tracking, and increased use and development of them are necessary for the establishment of a nationwide tracking network capable of linking environmental exposures and health outcomes.