A cytogenetic study was performed of employees and control persons of waste disposal sites in North Rhine-Westphalia, Germany, and of a copper recycling plant in Ilsenburg/Harz. These workers are exposed not only to metal compds. but also to polychlorinated dibenzodioxins/furans (dioxins). The results reveal an enhanced level of chromosomal damage in persons with occupational exposure to tip releases or metal compds. and dioxins. Esp. remarkable is the occurrence of multiaberrant cells obsd. in waste disposal site workers.