E-waste polluting Delhi’s groundwater, soil: study

Improperly-handled electronic waste may be contaminating sections of the city’s groundwater and soil, according to a study by researchers at Jamia Millia Islamia.

The scientists analysed soil samples from Mandoli’s Krishna Vihar — which has several mounds of unprocessed electronic waste — and found, among other pollutants, copper in the region’s topsoil to be about 283 mg/kg. Just 5 km from the site, which was chosen as reference site, copper levels were around 8.39 mg/kg.


Similarly, lead in the subsoil at the dump yard was 183 mg/kg and only 0.43 mg/kg at the reference site. The subsoil is where plants take root. Therefore, contamination here can mean that these residues can be absorbed into plant systems and find their way into human tissues.

Heavy metal contamination in groundwater samples from the area was also significant. Metals such as lead, cadmium and copper were, on average, 20 times higher than levels considered safe by the Central Pollution Control Board (CPCB). Nickel and chromium levels were about five times higher than what is considered safe by the CPCB.

“Water in these areas is not suitable for drinking…. The heavy metals are cause for possible risk to health by direct exposure and consumption of water,” said authors Rashmi Makkar Panwar and Sirajuddin Ahmed in the January issue of the peer-reviewed Current Science.

The risks

The risks of heavy metal consumption are well-studied. Organs most vulnerable to high levels of metals are kidneys and liver. Long-term consumption of these metals can also cause physical, muscular and neurological degenerative processes that cause Alzheimer’s disease, Parkinson’s disease, muscular dystrophy and multiple sclerosis.

A United Nations-backed report last December said only a fifth of the world’s electronic waste is collected or recycled under appropriate conditions. India generated nearly two million tonnes of the 44.7 million tonnes electronic waste produced globally in 2016.

In March 2016, India made it mandatory for electronics manufactures to ensure that a certain quantity of old, discarded electronic goods are safely disposed. This quantity was to be linked to their annual sales and was to increase every year.

However, more than 80% of such expended electronic goods make their way to the informal sector, where they are broken down — often unsafely — for ferreting gold, silver and other rare-earth metals, and then discarded in the open, where they fester and leach their metallic constituents into the soil.

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Printable version | Jan 16, 2022 6:54:08 AM |

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