Impact assessment of metal contamination in surface water of Sutlej River (India) on human health risks

The Sutlej river in Indian Punjab is getting contaminated by industrial waste, sewage, and agricultural runoff. Most of the previous studies on metal contamination of water are mainly confined to the small stretch of river. Therefore, a systematic study was carried out to assess the spatial and temporal variability of metal contamination in water from the entry point of Sutlej River in Indian Punjab to its tail end when it leaves the country. The likelihood of cancer risk was also estimated though human health risk assessment. The water samples (between 76 and 91) were collected from Sutlej river during pre- (April) and post-monsoon (September-October) seasons of the years 2017 and 2018. There samples were analyzed for 10 metals (Zn, Cu, Fe, Mn, Ni, Cd, Pb, Co, Cr and As) using Atomic Absorption Spectrophotometer. Results showed that metal concentration in water was higher along the transboundary during both the seasons. The concentration of metals in water was higher in pre-monsoon season than post-monsoon season. Multivariate analysis in different seasons showed that biophysical variables and social drivers (including anthropogenic activities) have great influence on the concentration of metals. Spatial distribution of all the metals in water and heavy metal pollution index showed that metal contamination was higher along the transboundary followed by the area from the confluence of contaminated drain with river to transboundary along with localized spots in the river flowing in Indian Punjab. The likelihood of cancer risk due to ingestion of metals through water was in the order: Cd > Ni > Cr > As and the risk is higher in the areas along the transboundary. These results are useful for formulating the action plan to improve the water quality of Sutlej river and its environs including water-soil-plant continuum which affect human health.