Bengaluru homes are getting water that contains arsenic. Study reveals that it contains hazardous pollutants that pose severe health risks to the residents, particularly children
Scientists from multiple institutes conducted human health risk assessment caused by dissolved trace elements in river systems in Bengaluru, Hyderabad, Chennai and Cochin and concluded that arsenic in the study areas poses potential health risk to the residents and indicates that the “ingestion of water over a long time could magnify the probabilities of cancer”.
“The results indicated arsenic as the most hazardous pollutant, which may cause non-carcinogenic and carcinogenic concerns, particularly in sensitive children.
Therefore, special attention should be paid to the issue of arsenic exposure for local residents, particularly children, and adequate measures need to be taken for sustaining a healthy aquatic ecosystem,” said the research team from Manipal University, Karnataka, University of Madras and National Agriculture and Food Research Organisation, Japan.
“In aquatic ecosystems, trace elements play an important role, as some of them are essential to biological organisms at low concentration, but a few are toxic even at trace levels, for instance, arsenic, mercury, lead and cadmium. Since surface water forms a major drinking water source for human and other organisms, it is important to know both concentration and biogeochemical interactions of trace elements in aquatic systems. In south India, major industrial hubs are located in the metropolitan cities of Bengaluru, Chennai, Hyderabad and Cochin; partially treated or untreated wastewater from such industries is discharged into various rivers and streams.
However, there is no active system for monitoring the water quality in these riverine systems, with regard to trace element concentrations. Therefore, the objectives of this study were to determine the concentration of various trace elements, and assess the related human health risk,” said the research team.
They collected and assessed concentrations of 27 trace elements in surface water samples from 48 sites of waterways (lakes, canals, and tributaries of major rivers) in four states: Karnataka, Tamil Nadu, Kerala, and Telangana. Analysis revealed that elements such as chromium, selenium, arsenic, iron, and manganese are the major pollutants, as their concentrations exceeded the acceptable national and international water quality standards in several sites of Vrishabhavathi, Ennore, Adyar, Cooum and Periyar rivers. Further, statistical analysis revealed that the Cauvery, Ennore, Adyar, Cooum and Periyar river basins are affected by various anthropogenic activities, leading to moderate-to-high pollution by arsenic, chromium, manganese, iron, and selenium. According to the scientists, potential pollution sources are industrial waste, sewage intrusion, paint industry waste, and automobile runoff.
“The data indicate that arsenic, chromium, copper, lead, cadmium, and vanadium concentrations are influenced by anthropogenic processes, including industrial waste, sewage, and automobile runoffs,” they added.
To evaluate the impact on people in Karnataka and Bengaluru, in particular, the researchers focused on surface water samples from the upper Cauvery basin, which revealed that iron and manganese are the major contaminants in this area. ‘’Iron concentrations at all locations along the Vrishabhavathi river, a tributary of the Cauvery, which flows through Bengaluru city, are almost twice those recommended by World Health Organisation (WHO), United States Environmental Protection Agency (USEPA), and Bureau of Indian Standards (BIS), suggesting that this river is a major contamination route to the Cauvery riverine system,” said the researchers. The highest iron concentration was recorded downstream Vrishabhavathi river. In addition, manganese concentrations at different locations along the Vrishabhavathi river are well above the USEPA criteria values, they concluded.
Experts said that exposure of human beings to trace metals could occur via three major pathways: ingestion, inhalation through mouth and nose, or absorption through skin. Since risk assessment identified “elevated concentrations” of arsenic at several sites, including those investigated in Karnataka, the researchers have said that immediate measures must be taken.
Credits Bangalore Mirror