Polychlorinated naphthalenes in air and snow in the Norwegian Arctic: a local source or an Eastern Arctic phenomenon?

PCNs were measured in air and snow during separate field campaigns at Ny-Alesund (April 2001) and Tromsø (February/March 2003) in the Norwegian Arctic. Air concentrations ranged from 27 to 48 and 9 to 47 pg sigmaPCN m(-3) for Ny-Alesund (n=6) and Tromsø (n=10), respectively. These concentrations (including the tri-chlorinated naphthalenes) greatly exceeded concentrations previously measured in the Canadian Arctic, but did fall within the upper range of concentrations observed over the eastern Arctic Ocean and regional seas. Local sources appear to be affecting concentrations observed at both sites, with the presence of several hexa-chlorinated naphthalenes at Tromsø probably attributed to local/regional sources. Use of air mass back trajectories at Tromsø revealed that background air concentrations in the Norwegian Arctic are likely to range between <9 and 20 pg sigmaPCN m(-3) and that contemporary concentrations derived close to potential sources (i.e. arctic towns) may equal or exceed those of PCBs. The mean concentration in surface snow was 350 and 240 pg sigmaPCN L(-1) (meltwater) (or 0.014 and 0.01 pg g(-1) (snow)) at Ny-Alesund and Tromsø, respectively. The wide variation in concentrations observed between fresh snowfalls could be explained by different snow densities (as a surrogate of snow surface area), rather than attributed to varying air concentrations. A statistically significant inverse relationship was found between snow density and concentrations of tri- to penta-chlorinated homologues and compliments similar findings for the polychlorinated biphenyls (PCBs). This suggests that the vapour-sorbed quantity changes rapidly with snow ageing/compaction; with implications for the fate of these chemicals in the Arctic.

Atmospheric emissions of polybrominated diphenyl ethers and other persistent organic pollutants during a major anthropogenic combustion event.

Air samples were taken for the analysis of persistent organic pollutants before, during, and after the national U.K. "Bonfire Festival" in November 2000. As expected, ambient levels of polynuclear aromatic hydrocarbons (PAHs) increased sharply in response to the widespread diffusive combustion processes that occurred at the time. Polybrominated diphenyl ethers (PBDEs) also increased at the suburban sampling location, to a greater extent than the PAHs. The rise and fall in PBDE concentrations was rapid, coinciding closely with the PAH "combustion markers". These data provide evidence for a novel mechanism responsible for dissipation of PBDEs into the environment. It is hypothesized that products treated with the penta-BDE product--notably household furnishing foams and textiles--have been subject to (unsanctioned) burning on private bonfires; even if the majority of the PBDE burden of such products is debrominated/broken down in the fires, it is shown that only small amounts of the total "stock" of penta product need be emitted to generate the concentrations detected. The mixture of PBDEs in the air during the Bonfire Festival was enriched in higher brominated congeners (e.g., BDE-99, -153, and -154) compared to that in background air. Estimates are made of the masses of compound classes that may have been emitted to the atmosphere during the festival.