Three classes of steroids in typical freshwater aquaculture farms: Comparison to marine aquaculture farms.

This study provides a comprehensive analysis of the occurrence of androgens, glucocorticoids and progestogens in typical freshwater aquaculture farms in comparison with marine aquaculture farms. The results showed that more steroids were detected in the marine aquaculture farms. For all aquatic products, the total concentrations of steroids in fish muscle were 22-2000ng/g, which were much higher than those detected in crabs, shrimps or mollusks (0.5-8.1ng/g). Based on the hazard index of the selected steroids, most water samples were in the low or medium risks. Some banned steroids were identified in the freshwater shrimps and all marine products, indicating that there may be certain health risks by the consumption of these aquatic products in the studied aquaculture farms. Furthermore, the total contributions of steroids in China were estimated to be 2300kg/y and 1200kg/y from freshwater fish culture and shrimp-crab culture, respectively.