Polychlorinated Biphenyls (PCBs) are ubiquitous in ambient air of densely populated areas, but in most cities the local sources are relatively unknown. Hydroxylated Polychlorinated Biphenyls (OH-PCBs) are an emerging environmental contaminant that are both breakdown products of PCBs and components of the original commercial mixtures. Although previously hypothesized, OH-PCB have not yet been reported in air. This study utilizes a passive air sampling (PAS-PUF) network to measure PCB concentrations in over 230 samples from 21 different sampling locations over a two year period from January 2012 to January 2014 in the Metropolitan Chicago area. A subset of 45 of the 230 samples were co-analyzed for the presence of 65 OH-PCBs. Both families of compounds were analyzed using gas chromatography with tandem mass spectrometry (GC-MS/MS). We have found ∑PCB concentrations ranging from 26 to 6200 pg m<sup>-3</sup> with an average of 540 ± 890 pg m<sup>-3</sup>. These values are comparable to previous studies in other metropolitan areas. Generally, airborne PCB concentrations measured using passive sampling with six-week deployment periods do not exhibit strong seasonal trends or correlation with air temperature. However, one site in Joliet, Illinois has displayed a statistically significant elevated level of PCBs, with a unique air signature (primarily Aroclor 1254). The data from this site follows a strong Clausius–Clapeyron correlation, suggesting a local PCB volatization source. Initial results of total mass of OH-PCB per PUF ranged from 2 pg to 510 pg, with an average of 83 ± 100 pg. Our results suggest a strong correlation between PCB and OH-PCBs levels in the samples. The sources of OH-PCBs appear to be from both direct volatilization and from atmospheric reactions.

Spatial and temporal variations of PCBs and OH-PCBs in the Metropolitan Chicago area using passive air sampling

250th National Meeting (2015)

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