PCBs in Our Environment

Polychlorinated biphenyls (PCBs) are a group of human-made chemicals that were commonly used in building materials and electrical equipment before 1980. Caulk, paint, glues, plastics, fluorescent lighting ballasts, transformers and capacitors are examples of products that may contain PCBs. The U.S. Environmental Protection Agency (EPA) banned manufacturing and certain uses of PCBs in 1979.

In recent years, PCBs have been found in schools in Vermont, New York City, Massachusetts and Connecticut. Lighting ballasts in older fluorescent lighting fixtures and caulk are the common sources of PCBs in school buildings. 

What You Need to Know About PCBs
What are the health effects of PCBs?

PCBs can cause serious health problems. The potential for health effects from PCBs, as with other chemicals, depends on how much, how often, and how long someone is exposed to them.

Numerous studies in both humans and animals have shown that exposure to PCBs can affect the nervous, immune, reproductive and endocrine (hormone) systems. PCBs are also classified as human carcinogens. This means that exposure to PCBs can cause cancer in humans.

Additionally, the different health effects of PCBs may be interconnected. This means that if one system of the body is affected by PCBs, it may have significant effects on other systems of the body, which can lead to many serious health problems.


The International Agency for Research on Cancer has studied the health effects of PCBs and concluded that PCBs are human carcinogens. This means that exposure to PCBs can cause cancer in humans.

Nervous System

Proper development of the nervous system is critical for early learning and can have significant effects on the health of people throughout their lives. Exposure to PCBs can lead to significant losses in neurological development, including visual recognition, short-term memory and learning.

Immune System

The immune system is critical for fighting infections. Diseases of the immune system can have very serious effects on human health. Exposure to PCBs can suppress the immune system, which can lead to other health problems.

Reproductive System

Exposure to PCBs can lead to decreased birth weight and can cause babies to be born too early.

Endocrine (Hormone) System

PCBs can affect thyroid hormone levels in humans. Thyroid hormone levels are critical for normal growth and development, and can have significant health effects if levels are altered.

How could I come in contact with PCBs?

PCBs continue to be widespread in our soil, air, water and food because of past use and disposal. PCBs break down very slowly and can remain in the environment for a long time. Most people have low levels of PCBs in their bodies because of the widespread presence of PCBs in the environment. In general, however, PCB levels in people have been going down since they were banned.

Food is the main source of exposure to PCBs for most people. PCBs are found in meat, dairy products and fish (especially fish caught in polluted waters).

In schools, the common sources of PCBs are old lighting ballasts and caulk. As the ballasts age, the PCB oil can leak onto nearby surfaces or produce vapors in the air. As caulk containing PCBs deteriorates, PCBs may be released into the dust or air. Students and staff may be exposed to PCBs by:

  • Breathing in dust or vapors that contain PCBs

  • Getting dust containing PCBs on their hands and then swallowing it while eating or drinking

  • Skin contact with materials that contain PCBs

What are the school action levels for PCBs in indoor air?

In Vermont, the school action levels are different depending on the lowest grade of students in the school. They are:

  • 30 ng/m3 for pre-K

  • 60 ng/m3 for kindergarten to 6th grade

  • 100 ng/m3 for 7th grade to adult

ng/m3 = nanograms per cubic meter

PCB Testing in Schools

Vermont has requirements for schools to test for PCBs and to make fixes if levels are high. In 2021, a Vermont law passed (Act 74) requiring all schools built or renovated before 1980 to test their indoor air for PCBs by July 2024. In addition, the Vermont Department of Environmental Conservation (DEC) has the authority to require schools to make fixes that will lower exposure to PCBs, if levels are found at or above the school action level.

Learn more about PCB testing in schools

Questions? Please email [email protected].

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