Carcinogenic and non-carcinogenic health risk assessment of river Ganges in different climatic conditions and regions of Uttarakhand, India

Abstract

Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), the two most significant physicochemical indicators, we find higher in water samples from plain regions than from hilly regions. Mean levels of As, Pb, Hg, Cd, Cr, Zn, and Ni were 5.48, 1.060, 4.4, 0.728, 3.5, 2.93, 26.56, and 7.68 (µg/L), respectively, in water samples, was within normal ranges, except Arsenic, which was found in higher at shukartal site > 10 µg/L. A marked correlation was observed between the physicochemical quality of water and bacterial density. The presence of specific bacterial strains, e.g. Enterococcus, Pseudomonas, Klebsiella, and Proteus spps., in higher concentrations suggests a significant level of faecal contamination in water. The Most Probable Number, Escherichia coli count, total coliform count, faecal streptococci count and faecal coliform count were discovered in the regions of Rishikesh, Roorkee, and Shukartaal, indicating that the total bacterial count was higher than the permitted range (GR1, GRR, and GS). The spatial distribution of the Hazardous index (H.I.) in the study area revealed a rising trend of environmental leaching from mountainous parts to plain regions. Children were at a higher carcinogenic risk compared to adults both males and females. The study recommends prevention and safeguarding against anthropometric variables.