FROM AIR TO HAIR: MERCURY CYCLING IN THE ARCTIC AND SUBARCTIC

Methylmercury is a potent neurotoxin and northern communities are especially vulnerable due to the large quantities of fish and marine mammals they consume. Elevated methylmercury levels have been reported in many Arctic ecosystems despite recent global declines in anthropogenic emissions. Elevated concentrations in Arctic biota have been attributed to enhanced atmospheric deposition and to the structure of Arctic food webs. Inorganic mercury deposited from the atmosphere to watersheds and ocean surface undergoes a range of physico-chemical and microbial processes during its conversion to methylmercury and uptake by biota. The drivers of methylmercury production and bioaccumulation are not well known and there exists no quantitative framework linking biogeochemical changes to human methylmercury exposures. Hence, we have a limited ability to forecast the spatial extent or magnitude of risks to human health following a perturbation.

Here, I will present our latest contributions to the understanding of methylmercury cycling in the Arctic and Subarctic. I will also discuss a study in which we predict changes in methylmercury exposures in a Subarctic Inuit community following an industry-driven perturbation.