Research fellow Gesellschaft für Strahlenforschung, Frankfurt, 1967-1972. Resident Internal Medicine Clinic University, 1974-1986. Head department environment and health Hamburg State Authority Health, Labor and Social Affairs.
Visiting scientist Mayo Clinic, Rochester, Minnesota, 1978-1979. Temporal adviser World Health Organization European Regional Bureau, Copenhagen, 1992-1999. Member several national committees regulatory toxicology German Government, Bonn and Berlin, since 1986.