How do polycyclic aromatic hydrocarbons cause cancer?

Polycyclic Aromatic Hydrocarbons can “slot” between the gaps in DNA bases. By reacting with DNA in this way and forming bridges between DNA called “adducts” they interfere with normal DNA replication processes such as unzipping leading to corruption of the DNA code. The hydrocarbons can also be reactive leading to oxidation of cell machinery and DNA repair enzymes. As the cells replicate with faulty DNA, they are often dysfunctional with irregular growth and replication cycles leading to tumourogenesis.