Bioaccumulation and Evidence of Hormonal Disruptions in Tilapia Fish (Oreochromis spp.) Exposed to Sub-lethal Concentrations of Pesticides in Sinaloa, Mexico

Abstract

Examination of endocrine disruption in tilapia fish (Oreochromis spp.) after exposure to sub-lethal concentrations of endosulfan, lindane, diazinon and malathion was evaluated by the quantification of 17-β-estradiol, progesterone and testosterone in fish. Female tilapia (96-110 g/fish) were exposed to 2.8, 15, 225 and 315 μg/l of endosulfan, lindane, diazinon and malathion, respectively; while, the male tilapia (same range weight)  were exposed to 2.8 μg/l endosulfan and 315 μg/l of malathion separately   for 21 days.  The obtained results showed that the level of 17-β-estradiol and progesterone concentration in female, were significantly decreased in all treatment.  Similarity, the level of testosterone was decreased significantly in the blood of male fish exposed to endosulfan and malathion pesticides when compared to the control fish group. The bioaccumulation of pesticides in muscular tissue of fishes were 760, 310, 41.3 and 11.9 (μg/g) for endosulfan, lindane, malathion and diazinon, respectively. Results suggest that pesticides assayed, are endocrine disruptors in tilapia, which can affect the reproduction and other biochemical and physiological functions controlled by hormones. On the other hand, pesticides accumulated in fish muscle represent a risk for public health, since tilapia is a popular food in Mexico like in others developing countries.