Read the full story in Environmental Factor.
An NIEHS-funded study showed that polychlorinated biphenyls (PCBs) are present in older schools and that the likely source is outdated building materials, including window caulking and light ballasts. The multi-year study is one of the largest to examine airborne PCBs in schools.
Marek RF, Thorne PS1, Herkert NJ, Awad AM, Hornbuckle KC. 2017. Airborne PCBs and OH-PCBs inside and outside urban and rural U.S. schools. Environ Sci Technol 51(14):7853–7860.