Polychlorinated bisphenyls (PCBs) were banned in the US in the late-1970s, but they still pose a danger to our health. They were widely used in electrical equipment (such as fluorescent light fixtures) and building materials (such as caulk and paint). Today they are found everywhere on Earth and in all people.
PCBs are endocrine disruptors, which means that they can mimic, block or change the effect of the body’s hormones.  Exposure has been linked to increased risk for many different health problems, including cancer, diabetes, and increased risk of infection. Exposure early in life can cause children to have difficulties with learning and memory. In addition, PCBs can increase blood pressure, triglyceride levels and cholesterol levels, which can increase the risk for heart attack, diabetes, and stroke.
Once PCBs are in our air, water, soil, homes, communities, or bodies, most do not break down easily. This means PCB levels are still a problem for all of us decades after they have been banned and will continue to be a problem for decades in the future. It also means that they build up in people’s bodies over the years.
The good news is that PCB levels in the environment and in humans are much lower now than they were before they were banned. 
So are PCBs still a health risk? Sadly, yes. Recent studies have shown that current levels of exposure still harm children’s health, including brain development.
For example, higher levels of prenatal exposure to PCBs increased the risk of language delay in 3-year-olds and resulted in less ability to focus on a task in 11-year-olds. Prenatal exposure also affects immune system development: babies exposed to higher levels while in the womb tend to have more infections as infants and toddlers.
Ongoing exposure also affects children’s development. A study of preschoolers found that higher levels of PCBs in house dust were linked to more anxiety/depression, aggression, and poorer motor skills.
A study of 3-year-olds found that children exposed to higher levels of PCBs had poorer hearing ability. And a study of 7-9-year-olds found that children with higher levels of some PCBs tended to have higher blood pressure and triglyceride levels.
People are primarily exposed to PCBs through food and air. For many people, the largest exposure comes from food, particularly meat, dairy and fish. PCBs build up in the fat of animals, so foods with more fat can contain more PCBs. However, for people who spend a lot of time in older buildings that were built with PCB materials, the air in these buildings is a major source of continued exposure.  An estimated 13,000 to 26,000 schools in the US still contain PCB-contaminated building materials. In addition to schools, many other older buildings also have contaminated construction materials.
Fluorescent light fixtures, caulk, adhesives, sealants, floor finish, and paint were often produced with high concentrations of PCBs. PCBs from these materials contaminate surrounding brick, concrete, carpet, dust, and soil. These indirectly contaminated materials can also have high levels of PCBs. In addition, PCBs move from these products into the air.
The main source of air contamination in many buildings are the caulk used to seal windows and doors. This is because it was often made with very high concentrations of PCBs (up to several thousand parts per million).  The levels of PCBs in the air of these buildings can be 10-to-hundreds of times greater than outdoor levels.  
Although it is illegal to purposely make PCBs, some are produced in the process of making pigments.   Therefore, PCBs are found in some paints, inks, clothing, cosmetics, plastics, and food packaging. They may also be created when making silicone and vinyl chloride (primarily used to make PVC). These contribute to the buildup of PCBs in the environment and our bodies.
There are ways to reduce exposure.
- Schools and other buildings can hire experts to remove or seal PCB-contaminated
- Choose low fat dairy products and trim the fat from meat, because PCBs accumulate in fat.
- If you fish or hunt, watch local advisories to know if there are concerns about PCBs in fish or animals in that location.
- Be careful around old electrical equipment if appears to have been leaking, because the coolant or lubricant could have high levels of PCBs. Wear gloves when handling the equipment because PCBs can be absorbed by skin. Don’t let children play near this equipment because the PCBs contaminate the surrounding soil and other materials. If you have contaminated materials, dispose them safely (see https://www.epa.gov/pcbs/managing-remediation-waste-polychlorinated-biphenyls-pcbs-cleanups).
All articles on our website have been approved by Dr. Diana Zuckerman and other senior staff.
- EPA (April 2016) Learn about polychlorinated biphenyls (PCBs). Accessed June 29, 2016. https://www.epa.gov/pcbs/learn-about-polychlorinated-biphenyls-pcbs
- International Agency for Research on Cancer (March 2013) Carcinogenicity of polychlorinated biphenyls and polybrominated biphenyls. Lancet. 14:287-288.
- Agency for Toxic Substances and Disease Registry (2000) Toxicological profile for polychlorinated biphenyls (PCBs). http://www.atsdr.cdc.gov/toxprofiles/tp17.pdf
- Xue J, Liu SV, Zartarian VG, Geller AM, Schultz BD (2014) Analysis of NHANES measured blood PCBs in the general US population and application of SHEDS model to identify key exposure factors. J Expo Sci Environ Epidemiol 24(6):615-621.
- Caspersen IH, Haugen M, Schjølberg S, Vejrup K, Knutsen HK, Brantsæter AL, Meltzer HM, Alexander J, Magnus P, Kvalem HE (2016) Maternal dietary exposure to dioxins and polychlorinated biphenyls (PCBs) is associated with language delay in 3year old Norwegian children. Environ Int 91:180-187.
- Ethier AA, Muckle G, Jacobson SW, Ayotte P, Jacobson JL, Saint-Amour D (2015) Assessing new dimensions of attentional functions in children prenatally exposed to environmental contaminants using an adapted Posner paradigm. Neurotoxicol Teratol 51:27-34.
- Stølevik SB, Nygaard UC, Namork E, Haugen M, Meltzer HM, Alexander J, Knutsen HK, Aaberge I, Vainio K, van Loveren H, Løvik M, Granum B (2013) Prenatal exposure to polychlorinated biphenyls and dioxins from the maternal diet may be associated with immunosuppressive effects that persist into early childhood. Food Chem Toxicol 51:165-172.
- Wang BL, Pang ST, Sun JP, Zhang XL, Li XL, Sun YG, Lu XM, Zhang Q (2015) Levels of polychlorinated biphenyls in settled house dust from urban dwellings in China and their neurodevelopmental effects on preschool-aged children. Sci Total Environ 505:402-408.
- Jusko TA, Sisto R, Iosif AM., Moleti A, Wimmerová S, Lancz K, Tihányi J, Šovčiková E, Drobná B, Palkovičová L, Jurečková D, Thevenet-Morrison K, Verner MA, Sonneborn D,Hertz-Picciotto I, Trnovec, T. (2014). Prenatal and Postnatal Serum PCB Concentrations and Cochlear Function in Children at 45 Months of Age. Environmental Health Perspectives, 122(11): 1246–1252.
- Lee HA, Park SH, Hong YS, Ha EH, Park H (2016) The Effect of Exposure to Persistent Organic Pollutants on Metabolic Health among KOREAN Children during a 1-Year Follow-Up. Int J Environ Res Public Health 13(3).
- Ampleman MD, Martinez A, DeWall J, Rawn DFK, Hornbuckle KC, Thorne PS (2015) Inhalation and dietary exposure to PCBs in urban and rural cohorts via congener-specific measurements. Envron Sci Technol 49:1156-1164.
- Meyer HW, Frederiksen M, Göen T, Ebbehøj NE, Gunnarsen L, Brauer C, Kolarik B, Müller J, Jacobsen P (2013) Plasma polychlorinated biphenyls in residents of 91 PCB-contaminated and 108 non-contaminated dwellings-an exposure study. Int J Hyg Environ Health 216(6):755-62.
- Herrick RF (2010) PCBs in schools- persistent chemicals, persistent problems. New Solutions 20(1):115-126.
- U.S. Environmental Protection Agency (2012) “Polychlorinated biphenyls (PCBs) in school buildings: sources, environmental levels, and exposures” Au:Kent Thomas, Jianping Xue, Ronald Williams,Paul Jones, Donald Whitaker; EPA/600/R-12/051 September 30, 2012. https://www.epa.gov/sites/production/files/2015-08/documents/pcb_epa600r12051_final.pdf
- Herrick RF, Stewart JH, Allen JG (2016) Review of PCBs in US schools: a brief history, an estimate of the number of impacted schools, and an approach for evaluating indoor air samples. Environ Sci Pollut Res Int 23(3):1975-1985.
- Wilson LR, Palmer PM, Belanger EE, Cayo MR, Durocher LA, Hwang SA, Fitzgerald EF (2010) Indoor Air Polychlorinated Biphenyl Concentrations in Three Communitites Along the Upper Hudson River, New York. Arch Environ Contam Toxicol 61:530-538.
- Guo J, Capozzi SL, Kraeutler TM, Rodenburg LA (2014) Global distribution and local impacts of inadvertently generated polychlorinated biphenyls in pgments. Envron Sci Technol 48:8573-8580.
- State of Washington Department of Ecology (June 2014) Polychlorinated biphenyls (PCBs) in general consumer products. https://fortress.wa.gov/ecy/publications/publications/1404035.pdf
- Hu D, Hornbuckle KC (2010) Inadvertent polychlorinated biphenyls in commerical paint pigments. Environ Sci Technol 44:2282-2827.
- Davies H, Delistraty (2016) Evaluation of PCB sources and releases for identifying priorites to reduce PCBs in Washington State (USA). Environ Sci Pollut Res 23:2033-2041.
- Koh WX, Hornbuckle KC, Thorne PS (2015) Human serum from urban and rural adolescents and their mothers shows exposure to polychlorinated biphenyls not found in commercial mixtures. Environ Sci Technol 49(13):8105-8112.
- Brown KW, Minegishi T, Cummiskey CC, Fragala MA, Hartman R, MacIntosh DL (2016) PCB remediation in schools: a review. Environ Sci Pollut Res 23:1986-1997.
- World Health Organization (June 2014) Dioxins and their effects on human health. http://www.who.int/mediacentre/factsheets/fs225/en/