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

Abstract

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’s legacy stocks hold 276 ±147 tonnes ΣPCBs, 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 ΣPCBs 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 ΣPCBs 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.

Sources and toxicities of phenolic polychlorinated biphenyls (OH-PCBs)

“…The commercial production of PCBs was banned in many countries since the late 1970s. However, PCB legacy materials and new materials containing PCBs from pigments continue to be a source of environmental release even today (Hu & Hornbuckle 2010, Hu et al 2010, Shanahan et al 2015).…”

Legacy PCB building remediation

“…Robson et al (2010) reported the detection of PCBs in buildings constructed as early as 1945 and could not determine if the presence was from new construction or refurbishment. Shanahan, Spak, Martinez, and Hornbuckle (2015) associated the use of PCB‐containing polysulfide sealants in buildings constructed between 1940 and 1979. The EPA (2009), (2010), (2012a) stated that PCB‐containing caulk was used in many buildings, particularly those constructed between 1950 and 1978.…”

An improved inventory of polychlorinated biphenyls in China: A case study on PCB-153

“…Annual PCB consumption in each province, municipality or autonomous region was further distributed by additional annual generating capacity between consecutive two years according to the following equation: 1975 ( 3)where Pa(i, j) is annual PCB usage in a provincial-level administrative region, ΔEc (i, j) is additional electricity consumption in that region in the jth year, which equals annual electricity consumption of the ith province in the jth year minus that in the (j-1)th year. PCB emissions might not be correlated well with population density at regional scale (Shanahan et al, 2015). Spatially usage was distributed using a new database including development periods, locations and installed capacities of about 3000 power plants or transformer substations established during PCB usage period ( Fig.…”