You are here:
Evaluating the application of multipollutant exposure metrics in air pollution health studies
Citation:
Oakes, M., L. Baxter, AND T. Long. Evaluating the application of multipollutant exposure metrics in air pollution health studies. ENVIRONMENT INTERNATIONAL. Elsevier Science Ltd, New York, NY, 69:90-99, (2014).
Impact/Purpose:
The U.S. EPA and the scientific community are beginning to explore multipollutant approaches to assessing air pollution health effects. The purpose of this article is to review multipollutant exposure metrics that have been developed to evaluate the health effects of air pollution mixtures, which may be based on common sources, exposures, or health effects. This review will impact the scientific community by focusing attention on the different approaches for evaluating and reporting health effects of multipollutant mixtures. Comparing the methods and describing strengths and limitations will facilitate improvements in multipollutant exposure metrics. Information synthesized in the review will impact the Agency by informing its planned multipollutant science assessments and consideration of air quality management options.
Description:
Background: Health effects associated with air pollution are typically evaluated using a single-pollutant approach, yet people are exposed to mixtures consisting of multiple pollutants that may have independent or combined effects on human health. Development of metrics that represent the multipollutant environment is important to understand the impact of ambient air quality on human health. Objectives: We reviewed existing multipollutant exposure metrics to evaluate how they can be applied to understand the association between air pollution and health effects. Methods: We conducted a comprehensive literature search using targeted search terms in Web of Science in April 2013. We focused on metrics that are constructed by pollutant concentrations and can be broadly applied to evaluate air pollution health effects. Discussion: Exposure metrics reviewed in this study can be categorized into those that group pollutants based on 1) atmospheric co-variance, 2) source emissions, or 3) common health outcomes. While comparing metrics, it was apparent that no universal exposure metric exists; each type of metric addresses different research questions. Key limitations of these metrics include the balance between complexity and simplicity and the general assumption of additive health effects of multiple pollutants. Conclusions: Research gaps remain in estimating the effects of multipollutant mixtures on health outcomes and understanding how well these metrics capture the concentration-exposure relationship. Future work on these aspects will advance multipollutant science and health research.
