Toxaphene carcinogenicity

Toxaphene caused a dose-related increase of hepatocellular carcinomas in mice fed 98 or 198 ppm for 80 weeks. In rats, there was a significantly increased incidence of neoplastic thyroid lesions at the high dose." The lARC has determined that there is sufficient evidence in experimental animals for the carcinogenicity of toxaphene and that it is possibly carcinogenic to humans. ... 

National Cancer Institute. Bioassay of Toxaphene for Possible Carcinogenicity. DHEW (NIH) Pub No 79-837. Bethesda, MD, Carcinogenesis Testing Program, Division of Cancer Cause and Prevention, 1979... 

National Toxicology Program, Third Annual Report on Carcinogens (Summary). "Toxaphene," p.126-7, NTP-82-330. USDHHS/PHS (Sept. 1983) V 229pp. 

Toxaphene Loss of consciousness, epileptiform convulsions, carcinogenicity... 

Toxaphene (approximate overall empirical formula of C10Hi0C15) is a persistent, broad-spectrum insecticide with some occurrence in drinking water. Its registered uses are currently limited. The EPA reported that toxaphene is highly persistent and accumulates in the environment. Acute exposure to toxaphene affects various organs in humans. Toxaphene has been classified in the EPA s Group B2 (probable human carcinogen). 

There is no data of carcinogenicity in humans, but toxaphene is classified as B2 probable human carcinogen based on bioassays in laboratory animals and positive mutagenesis results in Salmonella assays. 

The Environmental Protection Agency has established a limit of 0.003 mg 1 of drinking water and also requires that spills in excess of 1 lb be reported. The Occupational Safety and Health Administration (OSHA) has established a permissible exposure limit of 0.5 mg toxaphene per m for an 8 h day/40 h work week. The National Institute for Occupational Safety and Health recommends that toxaphene levels should at the lowest dose/concentration as possible in the workplace due to the potential for toxaphene to be carcinogenic in humans. The American Conference of Governmental Industrial Hygienists recommends a limit equal to that established by OSHA and that lmgm should not be exceeded over a 15 min period. 

Dietary pretreatment with DDT decreased the incidence of mammary tumors induced by dimethyl benzanthracene (21). Carcinogenicity of ethylene dibromide has been shown (18) to be increased by exposure to disulfiram. Induction of lung benzo(a)pyrene hydroxylase by carbaryl paralleled an Increase in lung tumors induced by benzo(a)pyrene (19). In the same experiments, pretreatment with toxaphene decreased the incidence of lung adenomas (19) and this correlated with the inhibition of lung benzo(a)pyrene hydroxylase. 

In the industry of insecticides, one of the central issues is to develop products that are not harmful to the environment and to human health. It has been shown that a-pinene, camphor and limonene can be good natural repellents for insects [155]. Besides the use of geraniol in the industry of fragrances, this compoxmd has also proven effective as a mosquito repellent [156, 157]. Terpene halides, 3-carene, and toxaphene, a chlorinated camphene, are important for agriculture because of their use as pesticides [158, 159]. However, especially for toxaphene, several restriction issues have been raised because of its pollutant capacity and carcinogenic potential in humans [159-161]. 

Twelve different chemicals are commonly referred to as POPs, including aldrin, chlordane, dichlorodiphenyl-trichloro-ethene (DDT), dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, PCBs, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and toxaphene. Other POP chemicals are considered carcinogenic and include polycyclic aromatic hydrocarbons (PAHs), brominated flame retardants, as well as some organometallic compounds such as trib-utyltin. 

The lARC classified aldrin, dieldrin and endrin as Group 3 chemicals not classifiable as to their carcinogenicity to humans, but all the other chlorinated hydrocarbons (chlordane, heptachlor, mirex, toxaphene, hexachlorobenzene, pentachlorophenol and... 

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