The Magnitude and Spatial Range of Current-Use Urban PCB and PBDE Emissions Estimated Using a Coupled Multimedia and Air Transport Model

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• 作者：Susan A. Csiszar ; Miriam L. Diamond ; Sreerama M. Daggupaty
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：January 21, 2014
• 年：2014
• 卷：48
• 期：2
• 页码：1075-1083
• 全文大小：426K
• ISSN：1520-5851

文摘

SO-MUM, a coupled atmospheric transport and multimedia urban model, was used to estimate spatially resolved (5 脳 5 km²) air emissions and chemical fate based on measured air concentrations and chemical mass inventories within Toronto, Canada. Approximately 95% and 70% of 危₅PCBs (CB-28, -52, -101, -153, and -180) and 危₅PBDEs (BDE-28, -47, -100, -154, and -183) emissions of 17 (2鈥?6) and 18 (3鈥?2) kg y^鈥?, respectively, undergo atmospheric transport from the city, which is partly over Lake Ontario. The urban air plume was found to reach about 50 km for PCBs and PBDEs, in the direction of prevailing winds which is almost twice the distance of the wind-independent plume. The distance traveled by the plume is a function of prevailing wind velocity, the geographic distribution of the chemical inventory, and gas-particle partitioning. Soil wash-off of historically accumulated 危₅PCBs to surface water contributed 0.4 kg y^鈥? (of mainly higher congeners) to near-shore Lake Ontario compared with volatilization of 6 kg y^鈥? of mainly lighter congeners. Atmospheric emissions from primary sources followed by deposition to surface films and subsequent wash-off to surface water contributed 1 kg y^鈥? and was the main route of 危₅PBDE loadings to near-shore Lake Ontario which acts as a net PBDE sink. Secondary emissions of PCBs and PBDEs from at least a 900鈥?00 km² rural land area would be needed to produce the equivalent primary emissions as Toronto (640 km²). These results provide clear support for reducing inventories of these POPs.