6. EVALUATING ECOLOGICAL RISK FOR THE OCCURRENCE OF HEAVY METAL IN SOIL IN INDUSTRIAL AREAS IN AN GIANG PROVINCE, VIETNAM

Tóm tắt

The study aimed to evaluate the concentration of heavy metals in the soil of industrial zones in An Giang province. Soil samples were collected at Binh Hoa and Binh Long industrial parks with 20 monitoring positions in the topsoil. The heavy metals including Copper (Cu), Zinc (Zn), Lead (Pb), Cadmium (Cd) and Arsenic (As) were analyzed by atomic absorption spectroscopy. The research results were compared with Vietnamese techinical regulation on the allowable limits of heavy metals in the soils (QCVN 03-MT:2015/BTNMT). In addition, the ecological potential risk index (RI) was applied to determine the level of risk of these industrial parks to the ecosystem using the risk assessment method of Hakanson (1980). The results showed that four out of five heavy metals including Cu, Zn, Pb and As were detected in the soil in Binh Hoa and Binh Long industrial parks at the concentrations of 24.7, 6.51, 14.18, 13.45 mg/kg and 22.63, 34.62, 2.87, 3.94 mg/kg, respectively. Most heavy metals are within the allowable limits of QCVN 03-MT:2015/BTNMT. However, As concentration at D3 and D8 points in Binh Hoa industrial park exceeded the standard by 18.79 mg/kg and 17.56 mg/kg, respectively. The results of RI showed that all the heavy metals pose low ecological risk in the study area. However, in the long term, the presence of heavy metals in the soil can be accumulated and affect ecosystems, which in turn impact human health. Therefore, monitoring of the soil and water environment for the detection of heavy metals is needed.