This project focuses on how toxic pollutants travel through the environment to affect human and ecosystem well-being. The toxic pollutants examined in this project are air pollutants that can be stored in land and water at the Earth’s surface, then re-released to the atmosphere (which we term here Atmosphere-Surface Exchangeable Pollutants or ASEPs). These pollutants travel in and interact in the environment at multiple scales, and interact with human activities, through governance and regulation as well as social dimensions of human exposure and risk. In this project, we will simulate the global transport of ASEPS to estimate land-atmosphere exchange under different future climate and land use scenarios. We will then quantify the economic costs in the United States of exposure to these chemicals, and will analyze efforts to manage the chemicals at scales ranging from local to global, with a geographical focus on the Laurentian Great Lakes. The study will examine details about the environmental cycling of these pollutants that currently impede our ability to model their global transport and fate and thus inform policy decision-making. The project will also assess the economic damages caused by these pollutants in the United States. Public outreach and distributed K-college education activities, and partnering between researchers, educators, stakeholders, and decision-makers, will promote incorporation of research results into learning, education and governance. This project brings together a diverse group of natural and social scientists from four academic institutions to study the problem of pollutants in a more holistic fashion than has ever been attempted to date, and may serve as a model for studying other classes of substance in the future.