White blood cell DNA adducts were measured in coke workers, local controls and countryside controls using the 32P-postlabelling technique. The method detected aromatic adducts including those formed by polycyclic aromatic hydrocarbons (PAHs). Coke workers are heavily exposed to PAHs particularly when working at the batteries. A difference in adduct levels was noted between the coke workers at the battery as compared to other jobs. The adduct levels in the non-battery were higher than those in the countryside controls.