秋冬季厦门岛大气颗粒物中PCBs的污染特征及入海通量

于2006至2008年秋季和冬季在台湾海峡西岸厦门岛采集大气颗粒物样品，分析28种多氯联苯（PCBs），包括指示性PCBs和类二恶英PCBs的含量特征及组成，探讨其可能来源，并对其干沉降入海通量进行估算。结果显示，2006至2008年秋冬季厦门岛大气颗粒物中PCBs的浓度分别为0.43~53.55、2.07~81.14和3.79~153.39 pg/m³，主要以高氯取代PCBs为主，类二恶英PCBs毒性当量值与主要城市相当。冬季PCBs浓度高于秋季，且2006至2008年的秋冬季PCBs浓度呈上升趋势，这可能受到厦门市汽车尾气和工业废气排放等人类活动导致大气颗粒物含量升高的影响。气团后向轨迹分析表明，冬季厦门岛大气颗粒物中较高浓度的PCBs主要受中国北方大陆污染气团来源的影响，而秋季大多来源于洁净海洋气团。秋季和冬季，大气颗粒物中PCBs的沉降通量分别为3.79和8.32 ng/（m²·d），按调查区域覆盖面积（63 000 km²）估算，通过大气干沉降向台湾海峡输入的PCBs量分别为22 kg和47 kg。

Characteristics and Fluxes of Polychlorinated Biphenyls in Atmospheric Particulates in Autumn and Winter in the Xiamen Island

Atmospheric particulates samples were collected in autumn and winter (from 2006 to 2008) at the western coast of Taiwan Strait, the levels and compositions of 28 Polychlorinated Biphenyls (PCBs) congeners, including indicator PCBs and dioxin-like-PCBs, were analyzed to investigate possible sources of atmospheric PCBs, and to estimate their dry deposition fluxes. The results showed that the concentration ranges of total PCBs in atmospheric particulate samples were 0.43-53.55, 2.07-81.14 and 3.79-153.39 pg/m³, respectively, for from 2006 to 2008, the high-chlorinated PCBs were dominated components, and the toxic equivalents (TEQs) of Dixon-like-PCBs were similar to those reported for urban areas. It was observed that concentrations of PCBs were higher in winter than in autumn. The concentrations of PCBs showed upward trends from 2006 to 2008, indicating ascendant automobile and industrial emissions in Xiamen. The air mass backward trajectory analyses showed the higher concentration of PCBs in winter resulted mainly from heating and industrial emissions from the north, while the air mass in autumn mostly came from the "clean" air of ocean. Dry deposition fluxes of PCBs in Xiamen Island were 3.79 and 8.32 ng/(m²·d). The input of PCBs from atmosphere to the Taiwan Strait via dry deposition were 22 kg and 47 kg.