Disruption of male sex hormones with regard to pesticides: pathophysiological and regulatory aspects.

Several pesticides used as herbicides, insecticides and fungicides are known to be endocrine disrupting chemicals (EDCs). In three pair-matched studies we found changes in sex hormone concentrations and T-lymphocytes in relation to acute and chronic pesticide exposure. After acute exposure, 1 day later the concentrations of testosterone and especially estradiol decreased. T4- and T8-lymphocytes slightly increased. Effects of chronic occupational pesticide exposure were expressed by a higher level of testosterone and a larger ratio of T4-/T8-lymphocytes in comparison to control persons. Concentrations of LH in exposed men were higher after exposure than before. We assume an inhibition of the aromatase system by testosterone metabolites. The studies show two effects with regard to the duration of exposure: a hormonal and immune suppression after acute exposure and an activation of both systems following chronic exposure.