NIOSH-funded Research Helps Reduce Occupational Exposure to PCBs When Renovating Schools

PCB caulk was commonly used to seal the joints of brick, masonry, stone, and metal window frames.

A Story of Impact:

Polychlorinated biphenyls (PCBs) are toxic organic compounds once used in a variety of products ranging from transformers to oil based paints and plastics. Exposure to PCBs has shown multiple adverse health effects.¹ Due to high toxicity and harmful environmental effects, Congress banned the production of PCBs in 1978. Despite the ban, occupational exposures to this toxic compound still occur regularly. This includes when working with older products, buildings, equipment, and materials that were created with or used PCBs and still have the compound embedded in them.²

Research funded by the National Institute for Occupational Safety and Health (NIOSH), and conducted within the Education and Research Center at the Harvard School of Public Health, focused primarily on the blood PCB levels of construction workers who renovate schools built before 1978 in the eastern United States.³ Many buildings constructed prior to 1978 have PCBs in the paint and the caulking material used to seal joints, especially around windows and pipes.⁴ As aging schools are renovated, construction workers are disrupting, breaking, or grinding areas where PCBs are located. Dust containing PCBs can be released into the air during these activities contaminating the building and surrounding area, which puts not only construction workers at risk of respiratory exposure but also schoolchildren, teachers, and other workers. Research has shown levels of PCBs reaching as high as 81 parts per million (ppm) in the dust inside ventilation systems; however, the limit for bulk materials such as caulk and dust set by the Environmental Protection Agency (EPA) is much lower at 50 ppm.⁵ Further, related studies have found an increase in PCB plamsa levels for both teachers and construction workers.⁶