Atmospheric hexachlorobenzene determined during the third China arctic research expedition: Sources and environmental fate

In July to September 2008, air samples were collected aboard a research expedition icebreaker, Xuelong (Snow Dragon), under the support of the 2008 Chinese Arctic Research Expedition Program. All the air samples were analyzed for determination of the concentrations of Hexachlorobenzene (HCB). The levels of HCB ranged from 24 to 180 pg m−3, with an average concentration of 88 pg m−3. Generally, HCB were more uniform than other organchlorine pollutants in the North Pacific Ocean and the Arctic Ocean. Geographically, the average concentrations of HCB from high to low were in the following order: the Central Arctic Ocean (110 ± 57 pg m−3), the Chukchi and Beaufort Seas (93 ± 29 pg m−3), the East Asia (75 ± 49 pg m−3) and the North Pacific Ocean (69 ± 38 pg m−3). In the East Asia Sea and the North Pacific Ocean, both primary and secondary emissions of HCB from the nearby continents and/or oceans might contribute to the atmospheric HCB. In the Arctic, intense sea–ice melting in the summer of 2008 might result in the remobilization of HCB and enhance its atmospheric levels in this region.