A WATER ENVIRONMENTAL RISK ASSESSMNET OF MA RIVER IN THANH HOA PROVINCE

Abstract

This research was carried out to determine the level of ecological and heath risk of water quality of Ma river in Thanh Hoa province. We used data at 8 water monitoring points on the Ma River, Thanh Hoa province in the period 2011-2020 to calculate the water quality index (WQI), ecological risk index (RI) and health risk (RISH and HAZAD). Results have showed that 6/8 water monitoring locations (75%) have WQI scores of 76 and are suitable for domestic water supply purposes. Only 2/8 water monitoring sites (25%) have WQI scores less than 76 and can only be used for irrigation. Although the ecological risk level of the water environment of the Ma river was low, the level of health risk was at a worrying level. The risk index for the carcinogen As was moderate to moderate risk (RISH_water> 10^-4) and the risk index for the non-carcinogenic agent Mn was unacceptable (HAZARD_water > 1). Before using surface-wate of Ma river for domestic water supply, we should take measures to remove or reduce the concentration of As and Mn in the water to reduce the health risk of the people.