Toxic metal ions in water and their prevalence in Uttarakhand, India

Developmental activities, geological reasons and mixing of industrial wastes are responsible for the deteriorating quality of surface and ground water in the Himalayan state of Uttarakhand. The drinking water sources of 13 districts of Uttarakhand have been assessed for the presence of four toxic metal ions (arsenic, cadmium, chromium and lead). The health aspects of the four metal ions have also been reviewed according to the prescribed limits set up by the Bureau of Indian Standards (BIS) and World Health Organization (WHO). The present study reveals the absence of arsenic at almost all stations. Cadmium has been found only at Rudrapur, whereas chromium is found to be present in more than prescribed limits, in Kolti, Mussoorie and Dehradun. Significant presence of lead in the six districts of the state is indicative of the fact that proper management strategy of toxic metal ion remediation is required. Chromium and lead have exceeded the prescribed limit in 1.3 and 4.5% samples, respectively. However, as per BIS standard, cadmium is higher than the prescribed limit in 0.6% samples but according to the WHO standard, cadmium has exceeded in about 26% samples. Out of the total 156 samples analyzed, 6.4 and 33.3% samples have been found to possess the toxic metal ions in more than the prescribed limits as per BIS and WHO guidelines, respectively.