Environmental risk assessments of CuCl2 and AgSo4 toxicity in Gambusia holbrooki based on ISO 31000

Heavy metal pollution and its effect on biota are one of the human concerns nowadays. The amount of heavy metal in a medium, reaches more than a specific limit, it becomes toxic for those animals that live in the environment. The aim of this study was to assessments environmental risk based on ISO 31000 in water and the toxicity of heavy metal in fish (Gambusia holbrooki) through conduction of a static bioassay. Environmental risk management provides a basis for decisions about the most appropriate approach to be used to treat the risks. According to our results, Concentrations for Ag were 0.0016, 0.0035, 0.00625, 0.0125 and 0.025 mg/kg, respectively. Concentrations for Cu were 0.16, 0.35, 0.625, 1.25 and 2.5 mg/kg, respectively. Results showed that heavy metal toxicity (Ag & Cu) had a significant effect on fish. No Observable Effect (NOEL) for Ag and Cu were 0.0016 and 0.16 mg/kg, respectively, and No Observable Adverse Effect (NOAEL) of them were 0.025 and 2.5 mg/kg, respectively. Therefore, Ag toxicity was significantly very higher than Cu toxicity for fish. Environmental risk assessments based on ISO 31000 is a useful tool for all areas of risk and permits the identification of how and where it may be possible to improve controls.