Local sources versus long-range transport of organic contaminants in the Arctic: future developments related to climate change†

Abstract

Local sources of persistent organic pollutants (POPs) and Chemicals of Emerging Arctic Concern (CEACs) from use in communities, shipping, and industrial activity contribute to contamination as does long-range environmental transport. Increased human activity in the Arctic as the climate warms may enhance the significance of local sources. Furthermore, climate change may lead to secondary sources of POPs and CEACs from existing reservoirs in the Arctic. This review examines the emerging evidence for releases from these secondary sources of formerly deposited POPs and CEACs as the Arctic climate warms and the potential for future releases with increased infrastructure development and economic activity. Arctic permafrost degradation represents an important source of natural and anthropogenic polycyclic aromatic hydrocarbons (PAHs), and indications exist of releases of POPs related to permafrost thaw, from previous deposition as well as waste sites. Deposition of POPs and some CEACs to Arctic glaciers is relatively well studied while fewer studies explore the impacts of remobilization. Expansion of economic development has the potential for increasing emissions or creating new sources of CEACs in the Arctic. The predicted northward expansion of agriculture, aquaculture, and ship traffic could bring increased emissions of CEACs to northern waters, including pesticides not previously used in the Arctic. Increased industrial chemical use, e.g. fire-fighting foams, flame retardants, lubricant and plastic additives, is likely to occur following the expansion of infrastructure such as airports, seaports, mining, and oil and gas development. While PAHs are relatively well-studied, there is an urgent need for environmental measurements and modelling of emissions of CEACs associated with the expansion of economic activity in the Arctic as well as to predict the future release of legacy POPs from secondary sources, particularly from permafrost.