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|Section2= }} Benzo()pyrene is a polycyclic aromatic hydrocarbon found in coal tar with the formula C20H12. Its metabolites are mutagenic and highly carcinogenic, and it is listed as a Group 1 carcinogen by the IARC. The compound is one of the benzopyrenes, formed by a benzene ring fused to pyrene, and is the result of incomplete combustion at temperatures between and . In the 18th century, young British chimney sweeps who climbed into chimneys suffered from chimney sweeps' carcinoma, a scrotal cancer peculiar to their profession, and this was connected to the effects of soot in 1775, in the first work of occupational cancer epidemiology and also the first connection of any chemical mixture to cancer formation. Frequent skin cancers were noted among fuel industry workers in the 19th century. In 1933, benzo()pyrene was determined to be the compound responsible for these cases, and its carcinogenicity was demonstrated when skin tumors occurred in laboratory animals repeatedly painted with coal tar. Benzo()pyrene has since been identified as a prime carcinogen in cigarette smoke. When the body attempts to metabolise benzo()pyrene, the resulting diol epoxide reacts and binds to DNA, resulting in mutations and eventually cancer. ==Sources of benzo()pyrene== The main source of atmospheric benzo()pyrene is residential wood burning.〔Assessment of Benzo(a)pyrene Emissions in the Great Lakes Region, pp 23-24 http://www.epa.gov/ttnchie1/conference/ei20/session10/asoehl_pres.pdf〕 It is also found in coal tar, in automobile exhaust fumes (especially from diesel engines), in all smoke resulting from the combustion of organic material (including cigarette smoke), and in charbroiled food. Cooked meat products, regular consumption of which has been epidemiologically associated with increased levels of colon cancer〔Le Marchand L, Hankin JH, Pierce LM, Sinha R, Nerurkar PV, Franke AA, Wilkens LR, Kolonel LN, Donlon T, Seifried A, Custer LJ, Lum-Jones A, Chang W. Well-done red meat, metabolic phenotypes and colorectal cancer in Hawaii. ''Mutation Research''. 2002 Sep 30;506-507:205-14. PMID 12351160〕 (although this in itself does not ''prove'' carcinogenicity),〔Truswell AS. Meat consumption and cancer of the large bowel. ''European Journal of Clinical Nutrition''. 2002 Mar;56 Suppl 1:S19-24. PMID 11965518〕 have been shown to contain up to 4 ng/g of benzo()pyrene,〔Kazerouni N, Sinha R, Hsu CH, Greenberg A, Rothman N. Analysis of 200 food items for benzo()pyrene and estimation of its intake in an epidemiologic study. ''Food and Chemical Toxicology'' 2002;40(1):133. 〕 and up to 5.5 ng/g in fried chicken〔Lee BM, Shim GA. Dietary exposure estimation of benzo()pyrene and cancer risk assessment. ''Journal of Toxicology and Environmental Health Part A''. 2007 Aug;70(15-16):1391-4. PMID 17654259〕 and 62.6 ng/g in overcooked charcoal barbecued beef.〔Aygün SF, Kabadayi F. Determination of benzo()pyrene in charcoal grilled meat samples by HPLC with fluorescence detection. ''International Journal of Food Sciences and Nutrition''. 2005 Dec;56(8):581-5. PMID 16638662〕 In February 2014, NASA announced a greatly upgraded database for tracking polycyclic aromatic hydrocarbons (PAHs), including benzo()pyrene, in the universe. According to scientists, more than 20% of the carbon in the universe may be associated with PAHs, possible starting materials for the formation of life. PAHs seem to have been forming "only a couple of billion years after the Big Bang", are widespread throughout the universe, and are associated with new stars and exoplanets. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Benzo(a)pyrene」の詳細全文を読む スポンサード リンク
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