chemical Class

Polychlorinated biphenyls (PCBs)


Chemicals in the class:

PCB-1, PCB-2, PCB-3, PCB-4, PCB-5, PCB-6, PCB-7, PCB-8, PCB-9, PCB-10, PCB-11, PCB-12, PCB-13, PCB-14, PCB-15, PCB-16, PCB-17, PCB-18, PCB-19, PCB-20, PCB-21, PCB-22, PCB-23, PCB-24, PCB-25, PCB-26, PCB-27, PCB-28, PCB-29, PCB-30, PCB-31, PCB-32, PCB-33, PCB-34, PCB-35, PCB-36, PCB-37, PCB-38, PCB-39, PCB-40, PCB-41, PCB-42, PCB-43, PCB-44, PCB-45, PCB-46, PCB-47, PCB-48, PCB-49, PCB-50, PCB-51, PCB-52, PCB-53, PCB-54, PCB-55, PCB-56, PCB-57, PCB-58, PCB-59, PCB-60, PCB-61, PCB-62, PCB-63, PCB-64, PCB-65, PCB-66, PCB-67, PCB-68, PCB-69, PCB-70, PCB-71, PCB-72, PCB-73, PCB-74, PCB-75, PCB-76, PCB-77, PCB-78, PCB-79, PCB-80, PCB-81, PCB-82, PCB-83, PCB-84, PCB-85, PCB-86, PCB-87, PCB-88, PCB-89, PCB-90, PCB-91, PCB-92, PCB-93, PCB-94, PCB-95, PCB-96, PCB-97, PCB-98, PCB-99, PCB-100, PCB-101, PCB-102, PCB-103, PCB-104, PCB-105, PCB-106, PCB-107, PCB-108, PCB-109, PCB-110, PCB-111, PCB-112, PCB-113, PCB-114, PCB-115, PCB-116, PCB-117, PCB-118, PCB-119, PCB-120, PCB-121, PCB-122, PCB-123, PCB-124, PCB-125, PCB-126, PCB-127, PCB-128, PCB-129, PCB-130, PCB-131, PCB-132, PCB-133, PCB-134, PCB-135, PCB-136, PCB-137, PCB-138, PCB-139, PCB-140, PCB-141, PCB-142, PCB-143, PCB-144, PCB-145, PCB-146, PCB-147, PCB-148, PCB-149, PCB-150, PCB-151, PCB-152, PCB-153, PCB-154, PCB-155, PCB-156, PCB-157, PCB-158, PCB-159, PCB-160, PCB-161, PCB-162, PCB-163, PCB-164, PCB-165, PCB-166, PCB-167, PCB-168, PCB-169, PCB-170, PCB-171, PCB-172, PCB-173, PCB-174, PCB-175, PCB-176, PCB-177, PCB-178, PCB-179, PCB-180, PCB-181, PCB-182, PCB-183, PCB-184, PCB-185, PCB-186, PCB-187, PCB-188, PCB-189, PCB-190, PCB-191, PCB-192, PCB-193, PCB-194, PCB-195, PCB-196, PCB-197, PCB-198, PCB-199, PCB-200, PCB-201, PCB-202, PCB-203, PCB-204, PCB-205, PCB-206, PCB-207, PCB-208, PCB-209


Summary

Polychlorinated biphenyls, or PCBs, are toxic, persistent, bioaccumulative, and lipophilic ("fat-loving"). This means that PCBs build up and are stored in fatty tissues and fluids, such as breast milk, and can be passed on to fetuses and infants during pregnancy and lactation. The effects of PCBs have been studied in humans who were exposed through diet, work, and industrial accidents.

In humans, PCBs are linked to increased rates of a number of cancers, including malignant melanoma; non-Hodgkin's lymphoma; and brain, liver, biliary tract, intestinal, and lung cancers. The National Toxicology Program considers several PCB mixtures to be "reasonably anticipated" human carcinogens (NTP 2002). Likewise, EPA considers PCBs to be "probable" human carcinogens (EPA 2002b).

Additional effects of PCBs include respiratory effects, gastrointestinal damage (nausea, vomiting, abdominal pain), eye irritation, increased susceptibility to infection, and hypothyroidism (ATSDR 2000b; Persky 2001). Other possible health effects associated with PCB exposure are menstrual irregularities and decreased fertility in women. Inconsistent associations have been noted with breast cancer, non-Hodgkin's lymphoma, cardiovascular disease, sperm and fertility problems in males, and low birth weight and head circumference (ATSDR 2000b).

PCB exposure in the womb or during lactation is also associated with decreased IQ and impaired psychomotor development, decreased immune function, and skin disease (chloracne) (ATSDR 2000b). PCB poisonings in humans have caused fetal and infant death, birth defects, and brain damage in children exposed in the womb. In 1976, the manufacture of PCBs was banned in the United States because of concern for human health impacts; however, PCBs are still widely found in the general population of the U.S.

In animal studies, PCBs cause a wide variety of effects including liver and thyroid tumors; kidney, gastrointestinal, immune, urinary tract, and reproductive toxicity; altered lipid and carbohydrate metabolism; nail and nail bed changes; reduced fertility and birth defects. Specific birth defects include reproductive tract and skeletal abnormalities. PCBs are endocrine disruptors because they alter thyroid and adrenal hormone levels and function. PCBs cause significant neurotoxicity, including decreased exploratory behavior, learning, spatial and non-spatial discrimination, auditory deficits and altered levels of brain neurotransmitters (dopamine and serotonin) (ATSDR 2000b).




Polychlorinated biphenyls (PCBs)

Formerly used in hundreds of industrial and commercial applications, PCBs are linked to cancer and other adverse health effects. PCBs are persistent and bioaccumulative; though banned, they are still widely detected in the U.S. population.

Top health concerns for Polychlorinated biphenyls (PCBs) (References)

health concern or target organ weight of evidence
Birth defects and developmental delaysprobable
Brain and nervous systemstrong
Immune system (including sensitization and allergies)limited
Cancerlimited

Other health concerns for Polychlorinated biphenyls (PCBs) (References)

health concern or target organ weight of evidence
Reproduction and fertilityknown
Persistent, accumulates in wildlife and/or peopleprobable
Hormone activityknown

Toxicity Classifications (References)

classification governing entity/references
Cancer hazards: recognizedP65-MC
Developmental toxicity hazards: recognizedP65-MC
Endocrine toxicity hazards: suspectedBKH, WWF, BKH, RTECS, WWF
Known to be neurotoxic to humans, suspected developmental neurotoxinChemicals known to be neurotoxic to humans (Grandjean and Landrigan, 2006)
Limited evidence in humans - immune system toxicityATSDR (2000). Toxicological profile for polychlorinated biphenyls (PCBs): Health effects chapter. http://www.atsdr.cdc.gov/tfacts17.html
Nervous system toxicity - weight of evidence unknown/unassessedATSDR (2000). Toxicological profile for polychlorinated biphenyls (PCBs): Health effects chapter. http://www.atsdr.cdc.gov/tfacts17.html
Persistent, bioaccumulative toxicant - Oslo-Paris (OSPAR) Convention for the Protection of the Marine Environment of the Northeast Atlantic, chemical of concernOSPAR (2002). OSPAR List of Substances of Possible Concern. Secondary OSPAR List of Substances of Possible Concern. Secondary OSPAR. Place Published, OSPAR Convention for the Protection of the Marine Environement of North-East Atlanic.