Principal Investigator Noelle Selin
Research on global pollutant fate and transport, as described above, can identify sources of contamination. To address how this burden can contribute to human exposure and health, we link output of atmospheric models with health-relevant analysis. Our work in this area addresses both toxic, long-lived contaminants such as mercury and more traditional air pollutants such as ozone and particulate matter. For mercury, for example, we used the GEOS-Chem mercury simulation to drive ecosystem and ocean models, in order to identify the relative importance of present-day and historical sources to fish contamination (Selin et al., 2010). We found that while source contribution varied dramatically depending on ecosystem type, reducing U.S. contributions could bring exposure under health-relevant thresholds for some regions and ecosystems.
Linking models of atmospheric chemistry and human impact requires attention to uncertainties. In a series of two papers (Thompson and Selin, 2012; Thompson et al., 2014), we set out a method for assessing appropriate atmospheric model resolution for analyzing the health impacts of policy proposals. In a feasibility study, we used the regional atmospheric model CAMx to evaluate policy interventions for ozone for Houston, Texas, in the context of their air pollution health impacts. We showed that, considering uncertainties in health impacts, fine-resolution (4 km square) modeling for O3 provided similar results to coarser-scale models at 12 km when assessing air pollution health impacts. Applying this method U.S.-wide, we found that at national scale, health benefits calculated at even coarser resolution (36 km) agree within errors with finer-scale modeling (4 km).
Work in this area has used a variety of models, including GEOS-Chem, ecosystem mercury models, CAMx, and BenMAP. Group members and alumni involved in this work include Rebecca Saari, Amanda Giang, Mingwei Li and Tammy Thompson. Our funding has come from the U.S. Environmental Protection Agency, and the MIT Joint Program on the Science and Policy of Global Change.