In order to study the relative importance of endogenous and environmental factors for the individual relation between DNA damage and DNA excision repair, a method was developed for measuring quantitatively the persistence of N2-deoxyguanosine adducts formed in non-stimulated isolated human peripheral blood lymphocytes after in vitro incubation with 0.2 microM (+/-)anti-BPDE, applying 32P-postlabeling. Total binding of radiolabeled (+/-)anti-BPDE to DNA and its removal has been studied previously in human peripheral blood lymphocytes, but the method presented here enables the direct investigation of repair of the main (+/-)anti-BPDE-DNA adduct, which is implicated in benzo[a]pyrene-induced mutagenesis. Using this method, it was found that in lymphocytes, obtained from 5 individuals, most (+/-)anti-BPDE-N2-dG adducts are removed within the first 24 h after treatment, while interindividual differences appear to exist in both adduct formation and rate and extent of removal.