Keri Hornbuckle, Ph.D.
University of Iowa
NIEHS grantees discovered that finished cabinetry is a predominant and previously unknown source of airborne polychlorinated biphenyls (PCBs) in residential homes.
As a group, PCBs are classified as human carcinogens, and their manufacture has been banned in the United States since 1979. However, they are still found in the environment because of widespread historical sources and inadvertent production as manufacturing byproducts. To determine levels of PCBs present in and around homes, researchers collected samples of airborne PCBs using passive air samplers for a 6-week interval inside and outside 16 homes in Iowa.
From the air samples, they determined air concentrations of all 209 forms of PCBs.
They found that the PCB forms PCB 47, PCB 51, and PCB 68 accounted for up to 50 percent of measured indoor PCBs and at much higher levels than expected, with higher concentrations in recently-built houses.
After testing emissions from a variety of household items, including the stove, floor, and walls, they identified finished kitchen cabinetry as the major source of these three forms of PCBs. According to the study, the researchers suspected that the substances came from the decomposition of 2,4-dichlorobenzoyl peroxide, which is commonly found in modern cabinet sealants.
Citation: Herkert NJ, Jahnke JC, Hornbuckle KC. 2018. Emissions of tetrachlorobiphenyls (PCBs 47, 51, and 68) from polymer resin on kitchen cabinets as a non-aroclor source to residential air. Environ Sci Technol 52(9):5154–5160.