Inventory of PCBs in Chicago and Opportunities for Reduction in Airborne Emissions and Human Exposure

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• 作者：Caitlin E. Shanahan ; Scott N. Spak ; Andres Martinez ; Keri C. Hornbuckle
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：December 1, 2015
• 年：2015
• 卷：49
• 期：23
• 页码：13878-13888
• 全文大小：429K
• ISSN：1520-5851

文摘

Urban areas are important regional sources of airborne polychlorinated biphenyls (PCBs) and population-scale airborne exposure, yet a comprehensive bottom-up source inventory of PCB emissions has never been quantified at urban scales in the United States. Here we report a comprehensive parcel level inventory of PCB stocks and emissions for Chicago, Illinois, developed with a transferable method from publicly available data. Chicago鈥檚 legacy stocks hold 276 卤 147 tonnes 鈭慞CBs, with 0.2 tonnes added annually. Transformers and building sealants represent the largest legacy categories at 250 and 20 tonnes, respectively. From these stocks, annual emissions rates of 203 kg for 鈭慞CBs and 3 kg for PCB 11 explain observed concentrations in Chicago air. Sewage sludge drying contributes 25% to emissions, soils 31%, and transformers 21%. Known contaminated sites account for <1% of stocks and 17% of emissions to air. Paint is responsible for 0.00001% of stocks but up to 7% of 鈭慞CBs emissions. Stocks and emissions are highly concentrated and not correlated with population density or demographics at the neighborhood scale. Results suggest that strategies to further reduce exposure and ecosystem deposition must focus on the largest emissions sources rather than the most contaminated sites or the largest closed source legacy stocks.