Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Your Environment. Your Health.

Airborne PCBs in Urban and Rural U.S. Schools

Keri Hornbuckle, Ph.D.
University of Iowa
P42ES013661, P30ES005605

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study showed that polychlorinated biphenyls (PCBs) are present in older schools and that the likely source is outdated building materials, including window caulking and light ballasts.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.

Though none of the schools had PCB levels high enough to meet federal standards for immediate remediation, researchers found that exposure of school-aged children to PCBs by inhalation may be equal to or higher than exposure through diet.

The researchers collected indoor and outdoor air samples at six schools in Iowa and Indiana from 2012 to 2015. For the first time, they also measured hydroxylated PCB, a PCB metabolite. While PCB levels varied at each school and even within each classroom, the rates of childhood exposure were roughly the same in rural and urban areas. Concentrations inside schools were one to two orders of magnitude higher than concentrations outdoors.

PCBs were used for decades in many industrial applications, such as electrical equipment. Although their manufacture and use are now banned in the U.S., PCBs break down slowly and can remain in the environment for many years. According to the authors, reducing airborne PCBs in older schools may be accomplished by removing old caulk around windows and modernizing light fixtures.

Citation: 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.

to Top