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PCBs may play a role in the development of cancers of the immune system because some tests of laboratory animals subjected to very high doses of PCBs have shown effects on the animals' immune system, and some studies of human populations have reported an association between environmental levels of PCBs and immune response.
Because current human evidence is incomplete, there is only data suggesting the carcinogenic effects of PCBs in humans. [15] While little research has been done on the toxic effects of 2,2’,3,3’,4,4’-hexachlorobiphenyl, PCBs have been found to cause irritation in the eyes and when inhaled also in the airways.
PCB contamination in humans may come from drinking the contaminated water, absorption through the skin, eating contaminated aquatic life, and/or inhaling volatilized PCBs. PCB contamination is especially dangerous for pregnant and nursing women. The contamination can reach the fetus and potentially cause birth defects.
Ortho-PCBs may alter hormone regulation through disruption of the thyroid hormone transport by binding to transthyretin. [8] Coplanar PCBs are similar to dioxins and furans, both bind to the aryl hydrocarbon receptor (AhR) in organisms and may exert dioxin-like effects, in addition to the effects shared with non-coplanar PCBs.
Early studies on the effects of PBBs on human beings concerned the people in Michigan, United States who consumed PBB-contaminated animal products (see history of PBBs below). [3] A study of 327 girls aged 5–24 years in Michigan found those who were exposed in utero to PBBs at or above a level of 7 ppb found had an earlier age at menarche ...
PCBs are toxic to fish at high doses, and associated with spawning failure at low doses. Human exposure occurs through food, and is associated with reproductive failure and immune suppression. Immediate effects of PCB exposure include pigmentation of nails and mucous membranes and
Test results conducted in the fall showed the presence of PCBs, or polychlorinated biphenyls — toxic, man-made chemicals that were banned from being produced in the United States in 1979.
The detrimental health effects of PCB exposure to humans became undeniable when two separate incidents of contaminated cooking oil poisoned thousands of residents in Japan (Yushō disease, 1968) and Taiwan (Yu-cheng disease, 1979), [141] leading to a worldwide ban on PCB use in 1977.