Presence of toxic metals in State rivers higher than permissible limits

Study conducted by the Central Water Commission

Samples collected from Godavari river at Bhadrachalam, top the list by revealing traces of a total four toxic metals - arsenic, cadmium, nickel and iron - beyond the permissible limits. | Photo Credit: File photo

A recent study by the Central Water Commission found presence of more than one toxic metal beyond permissible limits in rivers of Telangana, sounding alarm bells for the health of water resources in the State, more so with regard to rivers flowing through sanctuaries and wildlife areas.

The study report was published after analysing the samples from a total 688 river water quality stations functioning in the purview of the CWC. It has multiple references of rivers such as Godavari, Krishna, Kinnersani, Wyra, Musi and Peddavagu in terms of toxic metal pollution.

Samples collected from Godavari river at Bhadrachalam, top the list by revealing traces of a total four toxic metals - arsenic, cadmium, nickel and iron - beyond the permissible limits.

Peddavagu, a tributary of the Godavari flowing through wildlife areas of the Asifabad district, revealed higher than allowable presence of iron and nickel in its samples collected near Gandlapet village of Nizamabad district. Similar is the case with the samples analysed from Wyra river at Madhira of Khammam.

Kinnerasani, another tributary of the Godavari, displayed higher traces of chromium and nickel, in its samples from Sangam village of Khammam. Manjira, the drinking water source for Hyderabad, too was found to have higher than permissible limits of nickel.

Across the country, water samples collected at 187 stations proved to have presence of two or more toxic metals beyond the permissible limits, while those collected at 180 stations were found within the permissible limit for all purposes, the report said.

In Telangana, samples were collected from 13 sites altogether, and the time period for collection was between August, 2018 and December, 2020.

The samples were tested for presence of arsenic, cadmium, chromium, copper, lead, nickel, iron and zinc.

Increased heavy metal presence may be attributed to anthropogenic activities such as mining for metal, smelting, foundries and other industries that are metal based, heavy metals used in pesticides, leaching of metal from different sources such as landfills, waste dumps, excretion, livestock and chicken manure, runoffs, automobiles and roadworks, besides natural causes, the report notes.

Large amounts of any of these metals may cause damaged or reduced mental and central nervous functions, and long term exposure may lead to slowly progressing physical, muscular, and neurological degenerative processes that mimic Alzheimer’s disease, Parkinson’s disease, muscular dystrophy and multiple sclerosis, it said.