Climate change is remobilizing toxic pollutants from long-term sinks such as ice and sea water in the Arctic reports a paper published online in Nature Climate Change this week. The finding suggests that this could potentially undermine efforts to reduce exposure to these toxic compounds.

The abundance of many persistent organic pollutants (POPs) has decreased in the Arctic atmosphere over recent years owing to regulation of their production and use. However, many POPs remain stored in reservoirs such as sea water and ice because they are resistant to degradation.

Climate change could remobilize POPs from these stores, but observational evidence for this effect is limited. Based on 20-year-long records of POP concentrations in the Arctic atmosphere and modelling evidence, Ma and colleagues conclude that warming and sea-ice retreat have enhanced the release of several POPs from sinks such as ice and sea water over the past decade.

The abundance of POPs in the environment is likely to continue to decline in future, but remobilization of the compounds that the team studied — and potentially others like them — from long-term stores will make them available for atmospheric transport once again.