Effects of chlorinated hydrocarbons on sperm function in vitro.

For the past few years there has been controversial discussion of whether environmental pollutants in general, and chlorinated hydrocarbons in particular, may impair male fertility. Organochlorine compounds, e.g. dichlorodiphenyltrichlorothane (DDT) and metabolites, polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are highly persistent in the environment and there is therefore some concern about human exposure. These chlorinated compounds are universally found in human body fluids. Substantial amounts are detected in human body fluids associated with reproduction such as follicular fluid, seminal fluid and cervical mucus. The available data on male fertility and organochlorines are scarce and controversial. Fertilization rates in in vitro fertilization procedures were found to be decreased in couples in whom the male partner was exposed to pesticides. Data on the effects of PCBs on human sperm motility and acrosome reaction in vitro are controversial. Various PCDD congeners had no effect on human sperm motility in vitro. Effects of chlorinated hydrocarbons on sperm function in vivo seem to be unlikely since the concentrations used in vitro were far higher than those found in fluids of the human reproductive tract. However, negative effects on human spermatozoa in vivo cannot be totally excluded because other organohalogen compounds can be identified in the genital tract and little is known about their synergistic effects.