Industrial pollution, in varying forms ranging from lead acid battery recycling to landfill sites, has been affecting Delhi’s residents in adverse ways, as noted by a study of pollution hotspots by NGO Toxics Link.
The most worrying aspect, the study notes, is the manner in which such pollutants seep into the soil, lacing groundwater with heavy metals and other pollutants.
Pollution-generating industries, examined in the study — such as lead acid battery recycling, landfill sites, dyeing industries operating without effluent treatment plants, thermal power plants — were all found to have an adverse impact on ground water. For instance, the study notes that during recycling of lead acid battery in Prem Nagar, “the acid was haphazardly dumped on the ground in a waste pile or into the nearest water body,” leading to chances of percolation of lead oxide into ground water.
The study further says thermal power plants can also cause groundwater contamination “due to leaching of heavy metals present in fly ash”. The study also identifies the lack of a “leachate collection system” at landfills as a “major source of groundwater contamination”.
“Around the Okhla sanitary landfill (SLF) pH was found to be below 6.5, indicating that groundwater has turned acidic. Underground water samples near landfill sites at Okhla, Ghazipur and Bhalswa have been checked and found to be unfit for drinking purposes,” the study notes. Contamination is also caused by releasing untreated dyes into the water. Untreated water from a number of dyeing units in Delhi was found to be “directly released into the drain or thrown openly on the ground nearby” thus releasing dyes containing lead, cadmium, caustic soda — which may eventually make its way back into the ground water, the study says.
The contamination is made worse as many of these units are located near residential areas in the city. “In 2011, MCD was supposed to close down around 22,000 units, but not much seems to have been done till now,” Satish Sinha of Toxics Link said.
Doctors said the health risks of groundwater contamination were multi-fold. “It is possible that someone might be feeling the adverse effects of groundwater contamination, particularly the presence of heavy metals, without realising it. Problems ranging from body aches to neurological problems can occur due to long term exposure,” Dr S Chatterjee of Apollo Hospital said.