Quantification of groundwater-agricultural soil quality and associated health risks in the agri-intensive Sutlej River Basin of Punjab, India.

Abstract

The quality of drinking water and agricultural soil significantly affects the health of residents of the area. The quality of groundwater used as drinking and irrigation water along with agricultural soil of an agri-intensive region of the Sutlej River Basin (SRB), Punjab (India), has been investigated in the present paper to further access their impacts on human health. The quality parameters studied are pH, conductivity, cations, anions and trace elements/heavy metals. The spatio-distribution maps of major contaminates have been made. The distribution of major existing groundwater and agricultural soil contaminants has also been illustrated using inverse distance weighting interpolation technique. Further, the Pearson correlation matrix and principal component analysis (PCA) have been applied to explore the correlation and source apportionment analysis for the contaminants. Finally, the health risk assessment study has also been performed. The results showed elevated levels [compared to BIS acceptable limits] of bicarbonate and total hardness in more than 90% groundwater samples, while the concentration of Se and U exceeded in around 25% samples. Spatial distribution maps showed a non-homologous distribution pattern for most of the heavy metals except Zn, indicating their different origins. The significant existence of Se and U in groundwater and low content in soils indicated their geogenic origin. The Gibbs diagram suggested that rock-water interaction is the primary process controlling the chemical evolution of the groundwater in the region. The PCA indicated that Cu, Mn, Pb, NO3- and SO42- in groundwater have an anthropogenic origin, whereas Fe, As and U are mainly of geogenic origin. Significant positive correlations of heavy metals with Fe and Al in soils indicated scavenging of these elements by Fe/Al-oxyhydroxides minerals. Based on SAR, Na%, PI and corrosivity ratio analysis, it can be concluded that groundwater of the region is suitable for irrigation purposes Further, health risk assessment study indicated Cr and As are the possible cancer risk posing elements from both soil and groundwater. Non-carcinogenic risk assessment showed that cumulative exposure (hazard index-1.98) of U (HQ 1.21), NO3- (HQ 0.37) and F- (HQ 0.34) might pose harmful impacts to residents through groundwater ingestion in the long term. Although currently the contaminants in the groundwater-soil system may not pose any human health risks, continuous long-term monitoring is required to keep a check on the changes in their quality with time.