Delhi, Mumbai, 4 more Indian cities hotspots for rising Nitrogen Oxide levels: Report

Transport and industrial clusters are reportedly giving rise to the India's worst Nitrogen Oxide hotspots.


Several Indian cities, including the national capital, are major hotspots for rising levels of nitrogen oxide, a dangerous pollutant which contributes to the formation of ozone, an analysis has revealed.

Ozone is a deadly gas — even short duration exposure can worsen respiratory conditions and asthma and lead to emergency hospital admission. It is not directly emitted from any source, but is formed from reaction between gases in the air under the influence of sunlight and high temperature.

An analysis by environmental NGO Greenpeace India said that as per NO2 satellite data, transport and industrial clusters are giving rise to the country's worst Nitrogen Oxide (NOx) hotspots like Delhi, Bengaluru, Mumbai, Kolkata, Chennai and Hyderabad which have high vehicular population and diesel consumption.

Delhi, Mumbai, 4 more Indian cities hotspots for rising Nitrogen Oxide levels: Report

An auto rickshaw driver wears a mask to protect himself from the pollution in Delhi, India November 7, 2016. REUTERS/Cathal McNaughton

According to the data, which has been collected between February 2018 and May 2019, coal consumption and industrial clusters like Sonbhadra-Singrauli in Madhya Pradesh and Uttar Pradesh, Korba in Chattisgarh, Talcher in Odisha, Chandrapur in Maharashtra, Mundra in Gujarat and Durgapur in West Bengal were equally polluting when it comes to NOx emissions.

(Also read: Ozone pollution spikes in Delhi-NCR: Study by Centre for Science and Environment finds green areas to be more vulnerable)

"Over the past few years, several studies have identified PM2.5, NOx and O3 pollutants having a significant impact on human health. These are particularly dangerous air pollutants, causing respiratory illnesses and lung damage with acute exposure, and increasing the risk of chronic diseases such as heart attacks and lung cancer with long-term exposure," said Pujarini Sen, Senior Campaigner, Greenpeace India.

Tropospheric ozone (O3) is a secondary gaseous pollutant produced by photochemical oxidation of volatile organic compounds and carbon monoxide (CO) in the presence of nitrogen oxides (NOx).

The organisation analysed the satellite data generated using the methodology of Tropospheric Monitoring Instrument (TROPOMI), which monitors vertically integrated amount of several atmospheric trace gases, including NOx.

"NO2 is a dangerous pollutant in itself and also contributes to the formation of ozone and PM2.5, two of the most dangerous air pollutants. It is estimated that air pollution (ambient PM2.5 household and ozone air pollution collectively) caused 3.4 million deaths worldwide in 2017 and over 1.2 million only in India. PM2.5 alone resulted in more than 6.7 lakh deaths in India in 2017," the NGO said.

Demanding strict action from the government, the NGO demanded that all sources of Nox - transport, industries and power generation - should be tackled keeping in view the health emergency India faces today.

"Emission standard deadlines for coal power plants and industries must be strictly adhered to, even as the industrial and electricity sectors transition to cleaner alternatives for power generation. Every delay is literally costing lives," Sen said.

Referring to a 2015 report by IIT Kanpur, it said 90 percent reduction in NOx from power plants in a radius of 300 kms from Delhi can reduce nitrates by 45 percent which will effectively reduce PM10 and PM2.5 concentrations in Delhi.

Earlier this year, Air Pollution Global Cities Ranking Report released by Greenpeace found that 15 of the 20 most polluted cities in the world are located in India, highlighting the country’s air pollution crisis.

In January 2019, Airpocalypse III report by Greenpeace India, found 241 cities violating National Ambient Air Quality Standards (NAAQS).

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