20.10 Polyaromatic hydrocarbons
Polyaromatic hydrocarbons are aromatic compounds that are benzene rings fused together. Some simple ones are:
Naphthalene smells like mothballs. This is for good reason. Mothballs are made of naphthalene!
Larger fused benzene ring systems are often called polyaromatic hydrocarbons (PAHs). PAHs are implicated as cancer causing agents. PAHs are produced when substances like cigarettes or meat are burned. The tasty, burned edges of meat on the grill contain these. For that matter, the bits of charred material left on the grill contain PAHs. It is believed that PAHs actually become cancer-causing agents when they are oxidized into epoxides in the liver. These epoxides are electrophiles that can be attacked by nitrogen bases on our DNA. These PAHs then stick to our DNA causing a mutation.