Lamination workers are exposed to high concentrations of styrene. A postlabeling method was developed for the detection of styrene-specific DNA adducts of the workers. To synthesize a standard, styrene oxide was reacted with 2'-deoxyguanosine 3'-monophosphate (dGMP) and the O6-dGMP-adduct was isolated and characterized. The human samples were assayed by the nuclease P1 version of the 32P-postlabeling technique, using magnet transfer of the adducts in chromatography. The human samples were spiked with the standards to ensure identification and quantitation. In lamination workers the O6-adducts, adjusted for adduct recovery, were detected at a level of 5 adducts/10(8) nucleotides, over five times the level in the controls.