Persistent and bioaccumulative toxins like mercury pose unique challenges for environmental governance. The complexity of their movement through coupled social, technological, and natural systems can make it difficult to trace their path from emissions to wider impacts, as emissions and impacts can be separated both in time and space. This separation can make it difficult to assess whether different management and policy proposals will effectively reduce negative impacts. Focusing primarily on mercury, this dissertation explores how we can use interdisciplinary tools and approaches-from atmospheric modelling to community engaged research-to better trace this path from policy to human impacts, in support of environmental decision-making at multiple levels of governance. Combining simulation modelling, statistical, and qualitative approaches, it considers three aspects of the path from policy to impacts:​ how policy translates into emissions changes, how emissions changes translate into changes in environmental concentrations and fluxes, and finally how these environmental concentrations and fluxes impact the well-being of human communities. Taken together, the three studies highlight the need to take into account how social, technical, and natural systems interact, as well as the uncertainty, variability, and pluralism that exist within them, in our efforts to manage these toxic pollutants.

In the first study, I investigate the social and technical factors that affect the domestic implementation of a global environmental treaty (the United Nations Minamata Convention on Mercury) in major emitter countries in Asia, and their potential implications for emissions and global transport using a scenario-based modelling approach. I project that the benefit of avoided emissions and deposition over Asia are large, even when considering a scenario where the Convention allows large flexibility in implementation. These benefits are primarily driven by India, where even modest improvements in mercury capture are projected to result in large emissions decreases given future economic growth. I also find that climate change policies that promote the transitioning away from fossil may be as effective as strict end-of-pipe pollution control approaches for mitigating mercury emissions.

In the second study, driven by interests from community research partners in the Great Lakes region-an area vulnerable to mercury pollution-I use chemical transport modelling experiments to explore the conditions under which regional and global policy change can be statistically detected by wet deposition monitoring networks. I find that, given the magnitude of expected emissions decreases, detecting policy-related decreases in wet deposition in the Great Lakes region on the decadal scale will be challenging as the magnitude of noise-in particular interannual meteorological variability-can exceed this signal. These results suggest that these variabilities need to be better quantified and taken into account in both the design of policies for effectiveness and evaluation of policy compliance.

In the third study, I investigate the role that university-community partnerships can play in the long-term management of persistent pollutants through an empirical case study of the Superfund Research Program, which has recently required that grantees engage communities impacted by the hazardous substances that they study. I argue that community engagement in practice often supports a community building function-engagement operates as a space where knowledge about pollutants and shared identities of being impacted by these pollutants can be co-produced. Because persistent pollutants can implicate new people across time and space, often in ways that are difficult for those affected to discern, I suggest that supporting the constitution of what I call communities of concern is a critical way that university-based researchers can support the long-term management of persistent pollutants. I propose a conceptual framework to characterize and assess the functions that academic partners can perform in supporting the constitution of communities of concern around persistent pollutants. Further, I call attention to the institutional conditions that can enable this work to continue within academic contexts.