Samples of air taken from Delhi and Gurgaon in November and December 2018 have revealed the presence of alarming levels of toxic heavy metals such as manganese, nickel and lead, in addition to excess PM2.5, according to a study released by an NGO, Lung Care Foundation.
In the study, “Death in every breath”, results of seven air samples from New Delhi and Gurgaon were analysed. Levels of manganese in five samples were found to be much higher than the US standard while nickel concentration exceeded WHO guidelines in all seven samples. Lead levels exceeded the US safe standard in six samples and extremely high levels of barium were detected around Diwali.
PM2.5 levels in all the seven samples were above statutory limits, ranging from 90.3 ug/m3 to 563.5 ug/m3 — between 1.5 and 9.4 times higher than standards prescribed by the Union environment ministry.
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Manganese levels in five samples exceeded the US EPA reference concentration for exposure to to the metal (0.05 ug/m3) and the WHO annual health-based guidelines value of 0.15 ug/m3. There are no standards in India for manganese in ambient air.
Levels of lead in six samples exceed the US EPA threemonth average for exposure to lead (0.15 ug/m3) and in two samples exceed the Indian NAAQS annual and WHO annual health-based guidelines value of 0.05 ug/m3.
Nickel levels in all samples exceed the WHO annual healthbased guidelines value of 0.0025 ug/m3, which is based on the risk of cancer associated with long-term exposure to nickel.
“Manganese, lead and nickel are neurotoxins that damage the brain. Children are particularly vulnerable to the effects of lead. Exposures to even low levels of lead early in life have been linked to effects on IQ, learning, memory and behavior. It’s a matter of very serious concern that such high levels of these toxic metals are found in the air that our children breathe,” said Dr Arvind Kumar of Lung Care Foundation.
“There is an urgent need for policy makers to bring the focus back on the people and the health problems they are reporting, to understand the impact of air pollution and its severity. People are the best monitors and they have been reporting severe health impacts already,” he said.
The barium level in the sample collected a day before Diwali was 21.5 µg/m3. It was 5.8 µg/m3 on Diwali and 2.4 µg/ m3 the day after.
According to Dr Mark Chernaik, staff scientist at Environment Law Alliance Worlwide (ELAW), US, “These levels are extremely high and unheard of. Typically, barium levels are <0.05 µg/m3.” Based on limited human and animal data, the respiratory tract is the most sensitive target following inhalation exposure. According to studies, barium, typically as barium nitrate, imparts a yellow or apple green colour to fireworks. For brilliant green, barium monochloride is used.