Cytogenetic surveillance of workers exposed to genotoxic chemicals: preliminary experiences from a prospective cancer study in a cytogenetic cohort.

Cytogenetic endpoints, conventionally chromosomal aberrations, and later sister chromatid exchanges and micronuclei have long been used to assess exposure of human populations to genotoxic agents. Although the adverse nature of somatic chromosome damage is recognized at the group level, no ill-health manifestations have been causally related to cytogenetic damage at the individual level. In work-related exposures, e.g., ethylene oxide, styrene, benzene, vinyl chloride, and alkylating anticancer agents have been shown to induce somatic chromosomal damage in several studies. For all of these, a carcinogenic risk to humans has also been documented. The possible association of somatic chromosome damage and cancer will be elucidated in a Nordic prospective study. The objective is to find out the significance of a high or low score in any of the cytogenetic parametres to risk of cancer. In the Finnish part of the cohort of 806 individuals, 10 cases of cancer were observed during the first follow-up period. Although the cohort is young and the numbers small, a slightly significant (P = 0.04) trend was observed for individuals with cancer and a score of chromosomal aberrations. No trend was observed for sister chromatid exchanges. The application of cytogenetic surveillance is still not routine methodology, but it is useful and informative in carefully controlled study designs. Special efforts should be directed toward combining different disciplines, i.e., cytogenetics, adduct monitoring, and end-effect epidemiology, in order to reach quantitativeness in risk assessment.