The environment is negatively affected by the increasing accumulation of both natural and man-made waste and by-products. Organophosphorous pesticides –malathion, diazinon and methamidophos- are used worldwide in pest control. The aim of this report is to review the effects of organophosphates on the male reproductive tract of mice, rats and earthworms, and to evaluate their projection into the human population. Assessing failures in the male reproductive system is an excellent in vivo biomarker to determine the level of toxicity of suspected pollutants. In rodents organophosphates cause decreased testicular weight and sperm density, abnormal tubular plugging and increased teratozoospermia. In earthworms they cause a significant decrease in body weight and alter the spermatheca, with an initial significant increase in immature sperm followed by a significant decrease in sperm count with high frequency of metachromasia. Given the environmental impact of these pesticides -and their potential effects on human health-, international and regional organizations are warning about the correct handling and managing of these substances during work-related and domestic exposures and about their relation to water sources and food, placing a greater emphasis on the school children population due to its higher vulnerability, reduced detoxification capacity, and their endocrine and physiological effects.
KEY WORDS: Organophosphates; Cytotoxicity; Biomonitoring; Reproductive Health; Occupational Exposure.