Comparison of PCBs in East Chicago, Indiana and Columbus Junction, Iowa in indoor and outdoor air

Concentrations of PCB congeners were measured in indoor/outdoor pairs of 120 residences in two communities. More than 270 passive samplers equipped with polyurethane foam disks (PAS-PUF) were deployed and collected in the urban/industrial community of East Chicago, Indiana and rural Columbus Junction, Iowa. The sampling protocol included transport and storage of pre-cleaned and exposed PUF disks to and from the laboratory in Iowa City. The potential exposure to PCBs during transport and shipping was found to contribute no more than 10% of the PCBs measured in samples, although the sealed polyethylene bags were insufficient protection from ambient air over longer time periods. The samples were extracted and analyzed for the full suite of 209 polychlorinated biphenyls (PCBs) and are reported as a set of 158 individual or coeluting compounds. The quality control measures included laboratory and travel blanks, injection of surrogate standards in every sample, and analysis of certified PCBs in standard reference materials. Although we hypothesized that homes in East Chicago would have higher PCB concentrations than in rural Columbus Junction, this was not the case: the communities had no significant difference in either indoor or outdoor PCB concentrations (0.62 ± 0.65 ng m^-3 and 1.3 ± 1.6 ng m^-3 for outdoor air respectively and 1.9 ± 1.4 ng m^-3 and 1.9 ± 4.4 ng m^-3 for indoor air respectively). In both communities, indoor air was higher in concentration, with indoor/outdoor ratios averaging 3. The samples from the two communities do exhibit statistically different congener distributions, however, with higher molecular weight congeners more enriched in East Chicago.