Polycyclic aromatic hydrocarbons (PAHs) are organic compounds containing carbon and hydrogen. PAHs have carcinogenicity in human. Cancers related with PAHs include cancers of lung, skin, bladder, and others. International Agency for Research on Cancer (IARC) has determined several occupations that can be exposure to PAHs were probable carcinogens to human. National Toxicology Program (NTP) classified coal tars and coal tar pitches, and coke oven emissions as known to human carcinogens, and US Environmental Protection Agency (EPA) classified coke oven emissions as human carcinogen.

PAHs can be produced both naturally and artificially. Sources of occupational exposure include coal gasification, coke production, coal tar distillation, aluminium production, and so on. Diesel exhaust emission contains large amount of PAHs. Cigarette smoking also contains many PAHs, which is the important source of environmental source of PAHs.

The evaluation for work-relatedness and standards for recognition of occupational cancers should focus on occupations that can be exposed to PAHs. In Korea, standards for recognition of occupational cancers related with PAHs are following: lung cancers related with more than 10 years exposure to coal tar pitch, lung and skin cancers related with soot exposure, and skin cancers related with more than 10 years exposure to coal tar. When applying these standards, occupations that can be exposed to PAHs should be focused on. In addition, latent period for solid cancer should be considered. In addition to these occupations, diesel engine combustion and firefighters can be exposed to PAHs.