[Occupational medical research of male reproductive capacity].

During the past 15 years, approximately 50 occupational medical sperm quality investigations have been carried out in the world as a whole. The discovery of reduced testicular function among workers exposed to the chemical agent dibromochloropropane (DBCP) was an important incitment for the conduct of these investigations. These have not demonstrated new occupational medical influences with as dramatic an effect as DBCP but moderately reduced sperm quality has, however, been proved or suspected after occupational exposure to a series of other agents: certain cell poisons (ethylene dibromide, carbaryl, chlordecone), certain glycoethers (in paint, glue, printing inks, antifreeze solutions), certain organic solvents e.g. styrene (plastic casting), choroprene (plastic production), low exposure to lead, metal welding, thermal influences and high frequent electromagnetic fields (300 kHz-300 mHz). Only a few investigations illustrate the significance of the male factors for infertility and delay before deliberate pregnancy and there are still no well-proved examples of human paternal teratogenic agents or carcinogens. Our present knowledge only serves to prevent a limited proportion of reproductory failure in men. Reports of decreased sperm quality in the population and the influence of the environment on reproduction in domestic animals indicate that further investigations are necessary. Longitudinal investigations of sperm quality together with investigations of fertility or delay till deliberate pregnancy are proposed subjects for future strategy.