NIOSH Finds Potential Exposures to PCBs at University Building

A recently published health hazard evaluation (HHE) report describes the findings of NIOSH personnel who responded to concerns regarding potential occupational exposures to polychlorinated biphenyls, or PCBs, among employees working at a university building. University management requested the evaluation based on employees’ concerns and the results of sampling that found PCBs in indoor air and on building surfaces.

The building opened in 1971. Approximately 4,660 employees worked at the building between 1995, the first year for which the state could provide reliable information about cancer diagnoses, and 2022, when registry data about cancer diagnoses relevant to the NIOSH investigation was finalized. The university closed the building in November 2023.

PCBs were widely used in building materials and electrical equipment in the United States until 1979, when EPA banned their manufacture and importation. They have been associated with cancer and other adverse health effects.

NIOSH reviewed the results of air, surface, and bulk building sampling conducted from April 2018 through April 2024. All air samples were below EPA’s 0.5 µg/m3 exposure level for evaluating PCBs in school air, but some surface samples exceeded EPA’s threshold for nonporous surfaces of 10 µg/100 cm2, and many bulk samples exceeded the 50 mg/kg criterion for removal and disposal of PCB-containing materials according to the Toxic Substances Control Act. A consultant retained by the university concluded that the insulation sealant in the HVAC supply ductwork was the likely source of most of the PCBs found in the building.

Accounting for latency, NIOSH determined that 92 cancer cases among employees who worked in the building during 1995–2022 were relevant to its investigation. Thirty employees were diagnosed with melanoma, more than twice the expected number given the rate of melanoma in the state’s general population. NIOSH also found that the rate of breast cancer was greater than expected among employees who worked in the building, while the rate of non-Hodgkin lymphoma was approximately equal to that of the general population.

NIOSH cautions that its investigation was not designed to determine why higher rates of cancer occurred among building employees. The agency recommends that the university work with subject matter experts to determine the feasibility and usefulness of an epidemiologic study of potential links between PCB exposure in the building to cancer risk. Other NIOSH recommendations for the university include continuing to follow expert guidance on building remediation and to encourage employees who worked in the building to discuss their concerns with their healthcare providers.

For more information, refer to the HHE report (PDF).