Evaluation of surface water quality near pollution sources in Buriganga River and deciphering their probable emergence, ecological, and health risk aspects

Potentially toxic elements (PTEs) contamination in Buriganga river water, provoked by the point and non-point sources, has recently become a major health concern. Concentration, pollution degree, drinking and irrigation water potentiality, and associated health risks are the factors considered for this study. This study ascertained a mean pH, EC, TDS, and salinity value of 6.96, 86.25 μS/cm, 51.86 mg/L, and 86.56%, respectively, revealing that it is safe for drinking and agricultural purposes. Furthermore, the mean value of major anion (NO3−2 : 1.16, SO4−2 : 13.40, PO4−3 : 0.66, Cl−1 : 14.71 mg/L) and major cations (Na+1 : 16.95, K+1 : 4.26, Ca+2 : 17.63, and Mg+2 : 5.47 mg/L) also estimated safe for human consumption and agricultural use. Trace element evaluation index (TEI) value was found to vary among the sites and ranging from 4.40 to 10.50, indicating moderate pollution and risk imposed by the single PTEs can be ranked as Mn>Fe>Pb>As>Cu>Zn. Nemerow index and comprehensive pollution index value stipulated an insignificant to moderate pollution by the studied elements. Consequently, no ecological risk was posed via elements studied in the proposed sites. The emerging sources for PTEs are confined to both anthropogenic and lithogenic derivations. Non-carcinogenic risk assessment stipulated that the river water was safe for adults and children as the estimated Hazard Quotient (HQ) and Hazard Index (HI) value was found below the threshold value (HQ/HI<1). Total carcinogenic risk was calculated at 7.44E−08 and 1.60E−08 for adults and children, respectively, specifying no risk, and water from the sites was evaluated as suitable for agricultural irrigation purposes on the basis of estimated indices.