Superfund Research Program
Sources of Airborne PCB Congeners
In 2018, the Atmospheric Sources of PCB Congeners Project produced five reports about airborne sources of polychlorinated biphenyls (PCBs) and related compounds. For example, one paper describes Keri C. Hornbuckle, Ph.D., and her researchers' study of emissions of PCBs from the Indiana Harbor and Ship Canal where they deployed passive samplers in air and water simultaneously (Martinez et al., 2019). Another paper described a new method to determine the sampling rate and volume of air collected by passive samplers deployed indoors (Herkert et al., 2018b). Because no motors are needed, this novel method provides a more convenient, quiet, and accurate method for indoor sampling airborne PCBs. In addition, the researchers applied this method in a study of airborne PCBs in homes. Samplers were placed in sixteen homes and found airborne PCBs in each one. In several homes the researchers noticed an unusual signal of PCBs that was unrelated to their historical use. A new polyurethane foam based passive emission sampler (PUF-PES) was designed and used it to measure emissions of PCBs directly from flat surfaces in one of the homes. The researchers also discovered that the finished kitchen cabinets were a strong source of three PCB congeners. It was hypothesized that the polyester sealant used on the cabinets is the source and proposed a chemical pathway which may produce these three PCBs as inadvertent byproducts of the sealant manufacturing. This work attracted attention in the popular press, and motivated additional and ongoing studies on the importance of non-Aroclor sources of PCBs (Herkert et al., 2018c).