Heavy metal concentration in the sediments in aquacultural areas in An Giang province, Vietnam

Abstract

An Giang is an upstream province in the Mekong Delta, generating favorable conditions for aquaculture development. The area of aquaculture land in 2020 is 7,769 ha, accounting for 2.71% of the natural land area. Fishery production for the whole year reached 532.6 thousand tons, of which aquaculture reached 513 thousand tons. The study was carried out to determine the concentration of heavy metals (Cu, Zn, Pb, Cd, As) in the sediment of aquaculture ponds in the farming areas of Long Giang, Vinh Hoa and Vinh Thanh Trung, An Giang province. The results showed that the concentrations of heavy metals including Cu, Pb, Zn, Cd, As in the sediment samples were 19.81, 21.56, 15.12, 0,20.63 mg/kg; 68.91, 39.25, 69.99, 0, 0 mg/kg and 21.9, 13.5 , 23.68, 0, 0 mg/kg. Heavy metals in the sediment samples were all within the allowable limits of QCVN 03-MT: 2015/BTNMT, CCME (2007), except for As in Long Giang farming area, which exceeded the limit of QCVN 03-MT: 2015/BTNMT and CCME (2007). Initial research results showed that the sediment in the farming areas was contaminated with heavy metals. The ecological risk is low in the farming area. However, the presence of heavy metals can lead to bioaccumulation that affects ecosystem and human health. Future study should focus on speciation of heavy metals in the pond’s sediment.