Pathways of PFOA to the Arctic: variabilities and contributions of oceanic currents and atmospheric transport and chemistry sources
- ISSN: 1680-7324
- DOI: 10.5194/acp-10-9965-2010
Perfluorooctanoic acid (PFOA) and other per-fluorinated compounds are\nindustrial chemicals in use for decades which resist degradation in the\nenvironment and seem to accumulate in polar regions. Transport of PFOA\nwas modeled using a spatially resolved global multicompartment model\nincluding fully coupled three-dimensional ocean and atmosphere general\ncirculation models, and two-dimensional top soil, vegetation surfaces,\nand sea ice compartments. In addition to primary emissions, the\nformation of PFOA in the atmosphere from degradation of 8: 2\nfluorotelomer alcohol was included as a PFOA source. Oceanic transport,\ndelivered 14.8 +/- 5.0 (8-23) t a(-1) to the Arctic, strongly influenced\nby changes in water transport, which determined its interannual\nvariability. This pathway constituted the dominant source of PFOA to the\nArctic. Formation of PFOA in the atmosphere led to episodic transport\nevents (timescale of days) into the Arctic with small spatial extent.\nDeposition in the polar region was found to be dominated by wet\ndeposition over land, and shows maxima in boreal winter. The total\natmospheric deposition of PFOA in the Arctic in the 1990s was\napproximate to 1 t a(-1), much higher than previously estimated, and is\ndominated by primary emissions rather than secondary formation.