Levels and risk assessment of metals in sediment and fish from Chaohu Lake, Anhui Province, China.

Abstract

Chaohu Lake is the fifth largest freshwater lake in China, which tolerates substantial amount of anthropogenic discharge from surrounding cities that resulting in the degradation of water and damage of aquatic ecosystem. Metal analysis of sediment and aquatic organisms can provide important information on the environmental contamination and potential impact of aquatic food consumption. Thus, the concentrations of Cu, Pb, Zn, Cr, Cd, As, and Hg in sediment and fish from Chaohu Lake were analyzed with inductively coupled plasma mass spectrometry and atomic fluorescence spectrometry. The mean content of Cu, Pb, Zn, Cr, Cd, As, and Hg in the sediment samples were 27.4±6.3, 40.5±12.3, 136.8±65.5, 68.5±9.1, 0.357±0.141, 10.8±1.7, and 0.117±0.049mg/kg, respectively. The results were compared with background values and evaluation methods, to characterize the potential ecological risk. The concentrations of Cu, Pb, Zn, Cr, Cd, As, and Hg in the fish muscle samples were 1.68-5.31, 0.078-0.31, 15.55-372.98, 0.31-0.93, 0.001-0.033, 0.29-1.03, and 0.04-0.197mgkg-1 of dry mass, respectively. Most of the concentrations of the studied metals in muscles were found to be below the safe limits; however, the concentration of inorganic As (10% of total As) in two specimens exceeded the maximum allowance in fish. The ecological risk evaluation showed that the metals in sediment posed low to medium risk. The health risk assessment suggested that the consumption of fish from Chaohu Lake is currently safe with respect to the metals.