Aeolian contamination of Se and Ag in the North Pacific from Asian fossil fuel combustion.

Energy production from fossil fuels, and in particular the burning of coal in China, creates atmospheric contamination that is transported across the remote North Pacific with prevailing westerly winds. In recent years this pollution from within Asia has increased dramatically, as a consequence of vigorous economic growth and corresponding energy consumption. During the fourth Intergovernmental Oceanographic Commission baseline contaminant survey in the western Pacific Ocean from May to June, 2002, surface waters and aerosol samples were measured to investigate whether atmospheric deposition of trace elements to the surface North Pacific was altering trace element biogeochemical cycling. Results show a presumably anthropogenic enrichment of Ag and of Se, which is a known tracer of coal combustion, in the North Pacific atmosphere and surface waters. Additionally, a strong correlation was seen between dissolved Ag and Se concentrations in surface waters. This suggests that Ag should now also be considered a geochemical tracer for coal combustion, and provides further evidence that Ag exhibits a disturbed biogeochemical cycle as the result of atmospheric deposition to the North Pacific.