Benzo(a)pyrene (BaP) is a compound in a group of chemicals called polycyclic aromatic hydrocarbons (PAHs). PAHs like BaP are formed in the incomplete burning of coal, oil, gas, or other organic matter. Once formed, they can enter the air, water and soil. The most common way people are exposed to PAHs is by inhaling contaminated air. Vehicle exhaust, wood smoke, asphalt paving and agricultural burning can expose people to PAHs like BaP.

Exposure to BaP for even short periods of time can affect blood cells, leading to anemia and immune system defects. Exposure for long periods of time can affect function of the reproductive system. In studies of laboratory animals, prenatal exposure to BaP impaired learning and memory of offspring.

The most widely known effect of BaP exposure is cancer, and links between BaP and cancer have been known since the 1970s. BaP is one of many components of tobacco smoke that can cause lung cancer. BaP is dangerous because the body converts it into other compounds that can permanently change our cells’ DNA. This can cause cells to function improperly leading to cell death, abnormal cell growth, tissue damage and/or cancer.

CHEJ has previously written about PAHs here.