Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds that consist of at least two or more linked (fused) benzene rings. They are also referred to as fused ring systems. Because of their persistence, toxicity and ubiquitous distribution, PAHs are of great importance as pollutants in the environment. As early as the 1980s, the US Environmental Protection Agency (USEPA) included 16 substances from the several hundred individual PAH compounds in its list of "Priority Pollutants". Since then, these 16 "EPA PAHs" have been analysed mainly and representatively for the entire group of substances. They are: Naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene. pyrene, benzo(a)antracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h,)anthracene, indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene. Some PAHs are clearly carcinogenic in humans (e.g. lung, larynx, skin, stomach, colon and bladder cancer). There is a possibility of fruit damage or impairment of reproductive ability.

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