We have compared several biomarkers for polycyclic aromatic hydrocarbon (PAH) exposure among electrode paste plant workers and workers not occupationally exposed to PAH. The PAH exposure was quantitated from samples collected with person-attached sampling devices. The mean particulate PAH exposure level in the plant was 14.4 micrograms/m3. The level of pyrene was significantly correlated with both PAH level and the level of selected carcinogenic PAHs in this type of exposure. The mean concentration of the biomarker 1-hydroxypyrene in the PAH exposed workers' urine was 6.98 mumol of 1-hydroxypyrene per mole of creatinine compared with 0.08 and 0.14 mumol of 1-hydroxypyrene per mole of creatinine in the two reference groups. PAH-DNA adducts were measured in DNA from white blood cells by the ultrasensitive enzyme radioimmunoassay (USERIA) and the 32P-postlabeling technique. Only urinary 1-hydroxypyrene was significantly increased in the PAH-exposed group.