Environmental Exposure to Metals and Bioaccumulation in the Liver of Three Freshwater Species of Turtles from Two Different Rivers

摘要

Exposure to metals remains an important public health concern. The present study is a comprehensive field study to determine the concentrations of Cu, Zn, Ni, Cd, Co, Pb and Cr in water samples and in the livers of deceased freshwater turtles collected from pre-determined sampling sites of the Ravi and Chenab rivers. In total, 35 deceased freshwater turtles were collected from the sampling sites, and liver samples were collected and immediately stored at -20 degrees C prior to analysis. Heavy metals concentrations of Cu, Zn and Cd (0.073, 0.169 and 0.0042 mg/L-1) in water samples were collected from the Ravi and (0.084, 0.145 and 0.0041 mg/L-1) from the Chenab. Concentrations of Ni, Co, Pb and Cr were significantly lower (0.045, 0.018, 0.06 and 0.121 mg/L-1) in the Ravi while (0.045, 0.018, 0.064 and 0.121 mg/L-1) in the Chenab were significantly higher. Species-wise mean concentrations of all heavy metals were non-significant (P 0.05). The mean concentrations of Cu and Ni varied significantly (P 0.01) in the liver samples from the Ravi and Chenab. Regardless of the sampling sites, the mean concentrations of Cu and Pb recorded a maximum in K. Smithi (26.54 +/- 4.53 and 3.85 +/- 0.43 mg/Kg(-1), respectively) Zn in K. Tecta (42.48 +/- 4.06 mg/Kg(-1)) and Ni, Cd and Co in L. Punctata. Among the studied metals, Zn was recorded as most abundant (39.73 +/- 2.28 mg Kg(-1)) and Cd concentration was found to be minimum (0.188 +/- 0.017 mg Kg(-1)) in freshwater turtles collected from both sampling sites.