Phytoavailability and human risk assessment of heavy metals in soils and food crops around Sutlej river, India.

We assessed the phytoavailability of heavy metals in wheat and rice grown on soils along flood plains of Sutlej river (India) and its effects on human health. Surface soil samples along with wheat (pre-monsoon season) and rice (post-monsoon season) grain samples were collected during the years 2017 and 2018. Soil samples were analysed for total and DTPA-extractable metals and, wheat and rice grains samples for total metals. There were no significant (p < 0.05) changes in total metal concentration during both the years, but the concentration of DTPA-extractable metals was higher during pre-monsoon than post-monsoon season. The concentration of Pb, Cd, and Co in wheat grains, whereas the concentration of Cr, Co, Pb and Cd in rice grains surpassed their safe limits. Both DTPA-extractable metals (water soluble plus exchangeable) and non-exchangeable fractions explained more than 80% of the variations in metal uptake by plants. The bioaccumulation factor for DTPA-extractable metals (BCF) was above one, but Pollution Load Index for these metals (PLI) was less than one. The carcinogenic risks due to ingestion of wheat and rice grains were higher for Cd. The BAF, PLI and health risks were higher along transboundary of the river. These results suggest that exchangeable and non-exchangeable fractions are contributing towards metals uptake by wheat and rice along flood plain soils of the Sutlej river and the present study may act as a model for carrying out similar studies to find out the risks of heavy metals and it effect on human health in future.

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.