Sources, distribution, and health effect of carcinogenic polycyclic aromatic hydrocarbons (PAHs) – current knowledge and future directions

Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds containing two or more fused benzene rings in linear, angular or cluster arrangement, consisting of only carbon and hydrogen. Polycyclic aromatic carbons (PACs) include the unsubstituted hydrocarbons (PAHs) and substituted PAHs (e.g. nitro-PAH, oxygenated PAH). PAHs are the most stable form of hydrocarbons having low hydrogen-to-carbon ratio and usually occur in complex mixtures...