Carcinogenicity polycyclic aromatic hydrocarbons

Animal carcinogen One of several heterocyclic analogues of the polycyclic aromatic hydrocarbon carcinogens synthesized by Buu-Hoi et al. 

These analyses show major differences in the DNA reaction products formed by DMBA and by BP, a weaker but much more extensively studied polycyclic aromatic hydrocarbon carcinogen (35). 

These results show that pattern recognition can be used as an effective tool to characterize polycyclic aromatic hydrocarbon carcinogens. Using a set of only 28 molecular structure descriptors, linear discriminants can be found to correctly dichotomize 191 out of 200 randomly selected PAH s. This same set of 28 descriptors supports a linear discriminant function that has an average predictive ability of over ninety percent when subjected to randomized predictive ability tests. 

Dipple A, Bigger CAM. 1991. Mechanism of action of food-associated polycyclic aromatic hydrocarbon. Carcinogens. Mutat Res 259(3-4) 263-276. 

The polycyclic aromatic hydrocarbon carcinogens, which are very ubiquitous, are metabolized by the microsomal mixed-function oxidase system of target tissues to a variety of metabolites such as phenols, quinones, epoxides, dihydrodiols and dihydrodiol-epoxides ( ). The mqjor pathway of activation of benzo(a)pyrene (BP) leads to the formation of dihydrodiol-epoxide of BP which interacts predominantly with the 2-amino of guanine of DNA. The dihydrodiol-epoxide of BP appears to be the major ultimate electrophilic, mutagenic, and carcinogenic metabolite of BP ( ). Nevertheless, other metabolites such as certain phenols, epoxides and quinones may contribute to the overall carcinogenic activity of BP. In addition, a free radical mechanism may also be partly involved in its carcinogenic activity. 

Dunford HB (1987) Free radicals in iron-chelating systems. Free Radical Biol Med 3 405-421 Dunn BP, Fee J (1979) Polycyclic aromatic hydrocarbon carcinogens in commercial seafoods. J Fish Res Board Can 36 1469-1476... 

A large number of polycyclic aromatic hydrocarbons are known Many have been synthesized m the laboratory and several of the others are products of com bustion Benzo[a]pyrene for example is present m tobacco smoke contaminates food cooked on barbecue grills and collects m the soot of chimneys Benzo[a]pyrene is a carcinogen (a cancer causing substance) It is converted m the liver to an epoxy diol that can induce mutations leading to the uncontrolled growth of certain cells... 

Carcinogens Cancer-producing agents Skin Respiratory Bladder/urinary tract Liver Nasal Bone marrow Coal tar pitch dust crude anthracene dust mineral oil mist arsenic. Asbestos polycyclic aromatic hydrocarbons nickel ore arsenic bis-(chloromethyl) ether mustard gas. p-naphthylamine benzidine 4-am i nodi pheny lam ine. Vinyl chloride monomer. Mustard gas nickel ore. Benzene. 

Polycyclic aromatic hydrocarbons have been classified as human carcinogens because they induce cancers in experimental animals and because smoking and exposure to mixtures of chemicals containing polycyclic aromatic hydrocarbons in the workplace increase the risk of lung cancer in exposed individuals. In experimental animals, benzo(a)pyrene induces cancer in different organs depending on the route of administration.Furthermore, exposure to polycyclic aromatic hydrocarbons commonly occurs in occupations related to traffic (use of diesel engines in transportation and railways). 

Dihydro-9,10-epoxyphenanthrene and related arene oxides are of considerable interest as carcinogens formed by polycyclic aromatic hydrocarbons in vivo.45 Phenanthrene oxide does not isomerize to the corresponding dibenzoxepin under thermal conditions. Photolysis of... 

Benzo[a]pyrene, a molecule with five, fused, hexagonal rings, is among the most carcinogenic of the polycyclic aromatic hydrocarbons (PAHs). Such biological activity may be related to the electronic structure of benzo[a]pyrene and its metabolites. Ionization energies of these molecules therefore have been investigated with photoelectron spectroscopy [28]. 

IARC, International Agency for Research on Cancer (2010) IARC monographs on the evaluation of carcinogenic risks to humans, vol 92. Some non-heterocyclic polycyclic aromatic hydrocarbons and some related exposures. http //monographs.iarc.lr/ENG/Monographs/vol92... 

Acridine is a three-ring nitrogen heterocycle, classified as polycyclic aromatic hydrocarbons (PAHs), some of which are proposed to be human carcinogens based on the evidence of carcinogenicity in experimental animals. Acridine is present in crude oil and tar pitch, as well as in emissions resulting from their combustion. 

Two of the most carcinogenic compounds known dibenzo[a,l]pyrene, a polycyclic aromatic hydrocarbon (PAH) and aflatoxin Bi, a fungal metabolite. 

Man has served as the unintentional guinea pig for the identification of some major classes of carcinogens. These include the polycyclic aromatic hydrocarbons (PAH), or polyarenes, which have been identified as the active components of soot, which was recognized by the London surgeon Percivall Pott two centuries ago as responsible for cancer of the scrotum in chimney sweeps. Subsequently, polycyclic hydrocarbons have been implicated as agents responsible for skin cancer in other occupations such as shale oil distillation and mule spinning in the cotton industry. 

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