Organic chemicals of Arctic concern in Russian coastal seas

Arctic ecosystems face significant threats from chemicals of global concern. Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) have been consistently detected in the Arctic through decades of monitoring. POPs are known to bioaccumulate in food webs, and both POPs and PAHs are toxic posing risks to wildlife and human health. While regular monitoring activities have been implemented in most Arctic countries, information from the Russian Arctic is still limited. This review synthesizes the existing knowledge on environmental fate and distribution pathways of POPs, PAHs, and Chemicals Of Emerging Arctic Concern (CEACs) in the Russian Arctic. Except for recent studies on microplastics, data on CEACs remain very limited. Considering mass exchange processes between environmental compartments, including the cryosphere, this review focuses on the Russian Arctic coastal seas, where riverine transport and atmospheric deposition are the main sources of legacy POPs and PAHs. Northward-draining Russian Arctic rivers have been loading legacy POPs from historical sources to coastal seawater. Ongoing volatilization of low-molecular-weight PAHs from both sediments and seawater in the Russian Arctic coastal seas is likely to be accelerated with the ongoing warming climate. PAH and POPs stored in the cryosphere of the Russian Arctic are expected to be released with the ice/snow melting and permafrost thaws. However, more up-to-date information on these chemicals is needed to evaluate these processes and their significance for Arctic pollution.