What are poly-aromatic hydrocarbons?
Polyaromatic hydrocarbons or polycyclic aromatic hydrocarbons (PAHs) are hydrocarbons that contain more than one benzene ring.
PAHs are found in oil and coal and in tar deposits.
They are also produced during the incomplete combustion of fossil fuels, as in automobile engines.
Many PAHs are considered to be carcinogens.
The 16 priority pollutant PAHs a listed by the US Environmental Protection Agency (EPA) are