Definition: Polycyclic aromatic hydrocarbons (PAHs) are organic atmospheric pollutants that are present in fossil fuels. PAHs are also formed from the incomplete combustion of carbon-containing substances such as tobacco, wood, coal, diesel fuel and fat.
PAHs are dangerous to humans because some of them have been identified as carcinogenic. Meats cooked at high temperatures and tobacco smoke both contain PAHs.
See also: Harmful Chemicals in Cigarettes
