Different approaches for measuring occupational exposure to polycyclic aromatic hydrocarbons (PAHs) are presented, (i) determination of PAHs in the workplace by personal sampling, (ii) determination of urinary PAHs and PAH metabolites, and (iii) measurements of aromatic DNA adducts in white blood cells by ultra-sensitive enzyme radioimmunoassay (USERIA) and 32P-postlabelling. Large amounts of PAHs, including benzo[a]pyrene (BP), are released from the coke ovens. Mean PAH exposure levels were reduced by 60% when the workers used masks during work. However, low PAH concentrations were found in the urine of the exposed workers. Approximately 40% of the coke-oven workers had detectable levels of benzo[a]pyrene diol epoxide (BPDE)-DNA adducts in the white blood cells measured by USERIA and 90% had levels of aromatic adducts detectable by the 32P-postlabelling assay. In this study there was a correlation between DNA adduct levels and estimated exposure.