A comprehensive water quality analysis of 41 water bodies in Bengaluru has raised serious concerns about contamination, with dangerous levels of toxic metals exceeding the World Health Organisation (WHO) safe limits for drinking water. The study, conducted by the Geological Survey of India and other researchers, highlights that heavy metals such as uranium, lead, chromium, copper, and cobalt were found in several lakes, with 5% of them showing levels far above the recommended safety limits. Moreover, more than half of the water bodies surveyed exhibited unsafe pH levels, and 63% had high total dissolved solids (TDS).
Residents relying on these lakes for domestic and agricultural purposes face significant health risks. Researchers reported that exposure to metals such as chromium, nickel, and lead could pose carcinogenic threats to both adults and children. The findings underline the urgent need for action, as medium to high non-carcinogenic risks were also identified, stemming from pollutants associated with industrial waste and vehicular traffic. Comparisons to earlier reports indicate a worsening situation, with industrial areas, in particular, contributing heavily to metal pollution in the western part of the city.
From a sustainability perspective, the study underscores the importance of cleaner industrial practices and enhanced water management strategies. As contamination spreads through water bodies used for daily activities, the ecological impacts become increasingly dire. High TDS levels, linked to particulate matter, indicate a correlation with metals such as lead and copper, making water treatment a critical priority. The water bodies in northern and southern Bengaluru were found to have high concentrations of uranium due to geogenic sources, further complicating remediation efforts.
The civic challenges posed by the findings cannot be overlooked. The study revealed that 25% of lakes faced severe contamination, with Narasappanehalli Lake, located in an industrial zone, exhibiting the highest pollution levels. Compared to previous years, the situation has deteriorated, with areas like Deepanjali Nagar and Govindraj Nagar also reporting significant contamination. Researchers have warned that without immediate intervention, the health impacts will only escalate, affecting both urban residents and the agricultural sector reliant on these water sources.
