Polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals composed of multiple interconnected aromatic rings made of carbon and hydrogen atoms. They are formed during the incomplete combustion of organic materials like coal, oil, gas, wood, and tobacco. PAHs are found in substances such as soot, tar, charred food, and vehicle emissions. Some PAHs are known to be harmful because they can cause health issues, including cancer, when humans are exposed to significant amounts over time. They are also environmental pollutants, persisting in soil and water, and can accumulate in the food chain.