Summary of Results Linking PCBs and Skin Cancer

(Each entry represents one finding in a study. Some studies had multiple findings.)

• study found an association between PCB exposure in an occupational environment and mortality from malignant melanoma
• more deaths were observed than expected for malignant melanoma (8 observed, but less than 2 expected)
• all skin cancer deaths were due to malignant melanoma
• excess mortality applied to both sexes
• all 8 melanoma deaths occurred 5 or more years after initial employment
• risk of malignant melanoma was not related to cumulative PCB exposure.
• an association between employment at this factory and malignant melanoma seems to be evident
• mortality rates from malignant melanoma were increased among men with any experience in potentially PCB exposed jobs
• the data suggest that PCBs cause cancer, with malignant melanoma being of particular concern in the electrical industry
• an elevated number of melanoma cases occurred among 72 people studied
• there are biologic reasons for assuming a connection between exposure to PCBs and melanomas such as the occurrence of chloracne
• medical conditions which have arisen among the PCB exposed population include malignant melanoma of the skin
• medical surveillance indicated that PCB exposed workers showed signs of chloracne, transient skin rashes, and skin cancer
• several cases of skin cancer, including one malignant melanoma, were found in PCB exposed workers.
• an increase in the standardized incidence ratio was detected for malignant melanoma
• the risk for malignant melanoma and combined exposures to magnetic fields and possible exposure to electric discharges or to oils contaminated with polychlorinated biphenyls showed a tendency toward an effect.
• PCBs are halogenated aromatic compounds which cause chloracne
• skin lesions can develop into skin cancer
• melanoma and fluorescent lighting [with PCB-containing ballasts] may be associated
• the cluster of melanoma cases among workers in high energy research laboratories may be an example
• studies indicate PCBs may be involved in development of malignant melanoma
• the increasing incidence of malignant melanoma may be due to the interrelation of exposure to sunlight with chemical pollution of the environment
• a possible cause of malignant melanoma may be artificial stimulation of melanocytes with xenobiotic substrates or an excess of natural substrate
• excess risk for melanoma found in electrical engineers (3 deaths vs. 0.9 expected) --- [electrical equipment has frequently contained PCBs]

• electrical occupations were associated with a nonsignificant increased melanoma risk [electrical equipment has frequently contained PCBs]
• suggestive evidence of an increased risk of malignant melanoma due to proximity with electrical equipment
• four studies indicated elevated risks for malignant melanoma for electronics/electrical workers and electrical engineers 
• occurrence of cutaneous malignant melanoma was 3 times the expected figure among workers
• skin cancers were associated with engineering and electrical engineering duties [possibly exposed to PCB contaminated machinery & electrical equipment]
• skin cancers associated with building constructed in 1969 [with PCB paints, caulk or sealants?]

• an apparent excess of malignant melanoma has been reported in workers exposed to Aroclor 1254
• epidemiological data provide suggestive evidence of a relationship between exposure to PCBs and the development of malignant melanoma
• case reports and epidemiological studies indicate malignant tumors occurring after PCB exposure, including malignant melanomas
• PCBs should be regarded as carcinogenic to humans.
• a slight increase in the incidence of cancer, particularly melanoma of the skin, was reported in a small group of men exposed to Aroclor 1254, a mixture of PCBs.
• several early studies showed a significant excess of all cancers 
• indoors PCB exposure may be linked to malignant melanoma, through exposure to PCB-containing fluorescent light ballasts and other electrical appliances
• several studies of human mortality following PCB exposure were discussed in which cancer mortality rates for exposed workers were significantly elevated for skin melanoma
• workers heavily exposed to PCBs experience an excess of malignant melanomas
• tumors in patients who inadvertently consumed PCBs in 1968 have included one or more occurrences of malignant melanomas
• animal experiments and human studies have identified a wide variety of chemicals which are associated with malignant melanoma, including PCBs
• animal studies indicate that estrogens and estrogen progesterone combinations cause an increase in melanocyte count and melanin content (which may increase skin cancers) --- (certain PCBs are estrogen-mimics)
• PCBs are a suspected cause of malignant melanoma
• studies of workers exposed to PCBs have reported excess mortality from skin cancer (specifically malignant melanoma);
• primate studies may have included research on the relationship of PCBs and melanoma
• PCBs did not promote skin tumors in mice at the doses tested, using surface skin application
• evidence suggests that certain associated process streams in the production of petroleum products produce skin cancer (PCBs are a petroleum product)
• the relationship between occupational exposure to PCBs and the occurrence of chloracne was outlined, and the correlation between dermal availability and the occurrence of epidermal tumors was described
• study examined skin absorption of PCBs, toxicity and the relationship between the dermal bioavailability of hydrocortisone and the incidence of epidermal tumors (results not included)
• clear dose-dependent skin mutagenic activity was determined in the presence of PCB-induced rat liver homogenates [PCB-induced enzymes converted wood dust into a skin carcinogen]
• in Europe, cancers certified as occupational cancers are skin cancer caused by occupational exposure to carcinogens [including PCBs]
• PCB commercial mixes, Aroclor 1016 and 1254, did not have any effect on epidermal ODC activity and skin tumor development in mice, after skin application
• Aroclor 1242 provided a small synergistic effect on the induction of epidermal ODC activity
• PCB increased aryl-hydrocarbon-hydroxylase (AHH) activity in mouse and rat skin
• PCB increased total BaP metabolite (a procarcinogen) formation in mouse and rat skin
• PCB increased total phenols in mouse and rat skin
• different genetic strains of mice responded differently to PCBs
• PCB-induced liver enzymes metabolized certain PAH’s into more carcinogenic chemicals
• PCBs were used for enzyme activation, which was then blocked by curcumin (which inhibited skin cancer)
• certain PCBs did not induce skin tumors in mice after dermal application.
• two fractions of white snakeroot were metabolically activated to toxic agents by PCBs in skin cancer cell cultures

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The Studies of Skin Cancer and PCBs

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Studies Without Abstracts

References