University of Iowa researchers found polychlorinated biphenyls, or PCBs, in older schools, apparently from outdated building materials such as window caulking and light ballasts.
The multiyear study by the Iowa Superfund Research Program was one of the largest studies of airborne PCBs in schools. It found exposure rates to the cancer-causing industrial chemicals were roughly the same in urban and rural schools. Researchers were surprised to find the students were exposed to about the same amount of PCB through inhalation as they were through various foods they ate.
Researchers collected indoor and outdoor air samples at six schools in Iowa and Indiana from 2012 to 2015. Generally, PCB levels were below the concentrations that require immediate action. The study was published in Environmental Science & Technology.
In 2014, a school in Lexington, Mass., was closed after high levels of PCBs were found inside the building. New York City replaced light ballasts in 800 schools. Last year, parents in Malibu, Calif., won a court battle to force the removal of PCBs in schools.
"Due to the presence of PCBs in the environment, humans are easily exposed to them," Rachel Marek, assistant research scientist at the UI College of Engineering and lead author of the study, said in a statement. "Exposure of school-aged children to PCBs is of particular concern because these are compounds we know impair memory and learning and cause cancer in humans."