Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds comprised of two or more
fused benzene rings arranged in various configurations. PAHs are widespread environmental contaminants
formed as a result of incomplete combustion of organic materials such as fossil fuels. The occurrence of PAHs
in ambient air is an increasing concern because of their carcinogenicity and mutagenicity. Although emissions
and allowable concentrations of PAHs in air are now regulated, the health risk posed by PAH exposure suggests
a continuing need for their control through air quality management. In light of the environmental significance of
PAH exposure, this review offers an overview of PAH properties, fates, transformations, human exposure, and
health effects (acute and chronic) associatedwith their emission to the atmosphere. Biomarkers of PAH exposure
and their significance are also discussed.