Our research aims to inform sustainable management approaches to atmospheric pollutants, through understanding the processes and interactions of global environmental contamination from a systems perspective. Specifically, we develop new tools to better understand and quantify the pathway by which emissions of toxic substances travel and transform in the atmosphere to impact humans and the environment away from sources. The ultimate goal is to inform sustainability transitions. This research addresses fundamental scientific questions about the atmospheric behavior of contaminants, while addressing the engineering challenge of designing analytical tools to inform management strategies. As shown in the figure below, our research addresses a conceptual system in which human activities create emissions, pollutants are then transported near and far, leading to human exposure and eventual health impacts. These human and environmental impacts lead to economic consequences and policy responses (including regulation) which can then modify emissions. Our research examines all of the aspects of this system.
Our work has recently been funded by the U.S. National Science Foundation, the U.S. Environmental Protection Agency, Biogen, Inc., and the MIT Superfund Center.
Conceptual diagram
Atmospheric Fate and Transport of Pollutants
Our work examines how persistent, toxic pollutants travel in the environment. Mercury and POPs are global environmental pollutants influenced by human activities. The dominant source of anthropogenic mercury emissions is burning of coal, but industrial processes such as metals production and intentional uses of mercury are also sources. POPs can be intentionally produced (for use as pesticides and industrial chemicals) or emitted as byproducts of combustion or other industrial processes. Both mercury and POPs accumulate in food webs, posing risks to human health and the environment. Despite increasing attention to mercury and POPs as environmental problems, there are significant outstanding scientific questions regarding their behavior and chemistry in the atmosphere and biosphere. Constraining the cycling between the atmosphere and land and ocean reservoirs, and the extent to which the legacy of past anthropogenic activities affect current pollution, are critical needs. From a policy perspective, a key objective is to quantify the extent to which domestic and international emissions influence present-day deposition (and thus ultimately human exposure), so that emissions reduction activities can be implemented effectively.
Human Exposure and Health Impacts
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. Our funding has come from the U.S. Environmental Protection Agency and Biogen, Inc.
Economic Impacts and Policy Responses
Informing policy responses to air pollution often requires cost-benefit and regulatory analysis, which is widely used in U.S. decision-making. We use integrated assessment and other techniques to quantify the economic impacts of future pollution. From a policy perspective, our work has also addressed the ways in which policy-makers use scientific information.
Human Activities and Emissions
To close the loop illustrated in the figure above, we are developing new decision-relevant modeling tools to help decision-makers assess the sustainability impacts of policies. For example, we are interested in how climate policies (such as renewable fuel standards or cap-and-trade initiatives) can influence health-related economic damages from air pollution over the next several decades, and how Minamata Convention provisions will affect mercury over time. We are also conducting uncertainty and sensitivity analyses, developing new approaches.