Influx of e-waste from developed countries worsening soil contamination in metros: Study
Of the four metros, sites in Delhi recorded the maximum toxicity valuesmumbai Updated: Feb 27, 2018 11:32 IST
Soil from informal electronic (e-waste) recycling sites that recover metals, showed high levels of contamination across Delhi, Mumbai, Chennai and Kolkata, a study led by Tamil Nadu-based SRM University has found.
The study revealed that about 50% polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF), and almost three-fourth dioxin-like polychlorinated biphenyls (PCBs) were released from soil at precious metal recovery sites across the four metros.
“There is an increasing influx of e-waste from the developed world, and in due course of time the load of these toxicants from the e-waste recycling sites might have serious health impacts,” said Paromita Chakraborty, lead investigator, SRM University.
Of all the metros, the e-waste site at Mandoli in New Delhi, which used acid bath to recover precious metals, recorded the maximum toxicity values for PCDD (17pg TEQ/gm or pico gram Toxic Equivalent per gram) and PCDF (82pg TEQ/gm). The study explained that the values from Delhi are comparable to the household e-waste facilities of eastern China, where the crude acid leaching processes conducted by informal recycling sectors logged in 92pg TEQ/gm, as found in previous studies.
For open dumpsites, the highest toxicity values for PCDD and PCDF – 45pg TEQ/gm – was recorded at Kodangaiyur in Chennai.
Metal recovery sites of New Moore market in Chennai and Wire Lane at Bandra-Kurla Complex in Mumbai, were heavily loaded with dioxin-like PCBs. Their levels have increased by more than three folds in New Moore market when compared to their earlier observation, sampled during 2006-2007.
Of the 12 most toxic PCB compounds as categorised by the World Health Organization – there are a total 209 PCB compounds – the study found 86%-91% of four chemical compounds (PCB-71, 105, 114 and 118) and 30% PCB-126, the most toxic PCB compound in soil at e-waste metal recovery sites were associated with the burning wires during the copper extraction process or combustion of materials made of polyvinyl chloride (PVC). PCB-126 is not included in the technical formulations of PCBs.
The average concentration of 26 PCB compounds at informal e-waste recycling sites in four metros ranged from 0.4 nanogram per gram (ng/g) to 488ng/g, and that of PCDD/Fs was found to be between 1.0ng/g and 10.6ng/g.
To manage safe disposal of e-waste, the union environment ministry in its draft gazette notification under the E-Waste (Management) Amendment Rules, 2017, has proposed to make industry liable to collect 10% e-waste during 2017-18, 20% during 2018-19, 30% during 2019-20, and 40% during 2020-21.
“Whatever elements are there in the law should get implemented with producer’s taking responsibility for taking back e-waste. It may not be an absolute answer in the next one year. However, we will start the journey in the right course if producers meet the requirements as per the targets assigned to them,” said Satish Sinha, associate director, Toxics Link, a Delhi-based environment non-government organisation.
First Published: Feb 27, 2018 01:07 IST