Do PCBs from old school buildings affect children's health?

What's actually in it

Polychlorinated biphenyls (PCBs) were used in building materials from the 1950s through the late 1970s. They're in window caulk, floor tiles, paint, ceiling tiles, and fluorescent light ballasts. Schools built during this era often contain multiple PCB sources. The chemicals slowly evaporate from these materials into indoor air, even decades after installation.

What the research says

A 2026 study in Environ Sci Technol tested indoor air and building materials at schools across Vermont. The researchers found widespread PCB emissions from caulk, paint, and other original building materials in schools built before 1980.

Indoor air levels in some classrooms exceeded safety guidelines. Children in these schools breathe PCB-contaminated air for 6 to 8 hours a day, 180 days a year. PCBs are classified as probable human carcinogens and are known to disrupt brain development, thyroid function, and the immune system.

The study found that PCB levels varied widely between rooms, depending on how much original material remained. Classrooms with old window caulk had the highest concentrations. Simply opening windows helped somewhat, but didn't eliminate the problem.

PCBs were banned in 1979, but the buildings that contain them are still standing. Millions of students across the country attend schools built during the PCB era. Proper remediation requires physically removing contaminated materials, which is expensive but the only permanent fix.