Ecological risk of 17α-methyltestosterone contaminated water discharged from a full water recirculating earthen
masculinization pond

17α-methyltestosterone (MT) is an exogenous anabolic steroid hormone used widely in aquafarming. This study aimed to emphasize the environmental hazards of MT originated from a continuously operating masculinization pond with an intensive water recirculation system in Samut Prakan, Thailand. Risk quotient (RQ) and concentration factor (CF) were used to examine the ecological risk of MT in the pond environment. The results revealed relatively high MT concentrations in the water and sediments. These findings concurred the benefit of masculinization ponds with a water recirculation system in the way that it can effectively save the water and reduce the MT dosage that needs to be added into the feed. However, this could bring serious environmental concerns since releasing water containing MT residues and androgenic active metabolites through water overflowing from the masculinization pond to the environment during the wet season is inevitable. This is the first report indicating that CF relates to the androgenic potential activity and can be used to explain the ecological risk of MT contaminated water discharged from a full water recirculating earthen masculinization pond. This study provides important information indicating that CF values in a range of 7 to 16 are high enough to cause adversely affect the reproductive performance of tested fish (i.e., Probarbus jullieni, Barbonymus gonionotus, and Anabas testudineus).