Air Pollution | Key pollutant levels in air breach safe limits this summer: Report

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Air pollution may be perceived to be a winter problem, but a latest analysis of government data shows otherwise. A deep dive into  air pollution figures from the Central Pollution Control Board (CPCB) across 10 Indian cities shows that the monthly levels of key pollutants during the summer months breached the annual safe limits.

In Delhi, for example, the analysis found that pollution ingredients PM2.5 and PM10 recorded this summer were far above the safe limit and higher that last year. This comes days after a recent study commissioned by the Energy Policy Institute (EPIC) at the University of Chicago, revealed that air pollution had shortened life expectancy in the national capital by up to 10 years, and across the country by five years.

The analysis by NCAP Tracker looked at air pollution levels in Agra, Bengaluru, Chandigarh, Chennai, Delhi, Kolkata, Jodhpur, Mumbai, Lucknow and Patna from March to June this year and found that monthly PM 2.5 and PM 10 levels during these four summer months breached the annual safe limits of 40 ug/m3 and 60 ug/m3.

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NCAP Tracker is a joint project by Climate Trends and Respirer Living Sciences to create an online hub for the latest updates on India’s clean air policy, the National Clean Air Programme (NCAP). While the Indian Meteorological Department considers June as a monsoon month, it is mostly dry in several parts of the country and hence part of our summertime pollution analysis.

The analysis released on July 6 also said that nitrogen dioxide levels in New Delhi were went beyond the safe limit for two months – March and April – this year.

“Evidently, the PM 2.5 and PM 10 levels were higher this year compared to 2021 in most of the cities during summer. For instance, Delhi's PM 2.5 and PM 10 levels were higher in 2022 as compared to 2021 across the four months except in the case of PM 10 levels in March. Similar was the case in Patna. In both cities, the levels are over five times higher than CPCB standards,” the report said.

PM or Particulate Matter, is a mixture of solid particles and liquid droplets present in the atmosphere that are so small that when inhaled can cause serious health problems. PM10 stands for inhalable particles, with diameters that are generally 10 micrometers and smaller and PM 2.5 stands fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller.

The CPCB's annual average permissible limits for PM 2.5, PM 10 and NO2 are 40 ug/m3, 60 ug/m3 and 40 ug/m3 respectively. The World Health Organization's safe limits are lower at 5 ug/m3, 15 ug/m3 and 10 ug/m3 for the three pollutants respectively.

The analysis pointed out that this year, the country reeled under multiple heatwaves from as early as March with record-breaking temperatures all across with March being the warmest in 121 years and the country recording an average maximum temperature of 33.1 degrees Celsius, an all-time-high and 1.86 degrees Celsius above normal levels.

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“With the extreme heat also came a power crisis that resulted in more coal burning, a primary source of pollution. On June 10, India's power demand peaked at 211 GW against the peak requirement of 186 GW in 2021 and 75% of this was provided by coal-fired thermal power plants,” the report said.

All cities except Chennai recorded higher than permissible PM 2.5 levels in March 2022 and all cities breached permissible limits for PM 10 levels, among other takeaways from the analysis. Also, in April, levels improved only in Kolkata and it joined Chennai in the cities which did not breach safety limits for PM 2.5.

Chennai was also the only city with PM 10 levels within safe limits during April, it said. With some parts of the country receiving rains in June 2022, five cities – Agra, Bengaluru, Chennai, Kolkata and Mumbai – saw their PM 2.5 levels improve and within the CPCB safety limits.

Commenting on the analysis, Prof SN Tripathi, Steering Committee member, NCAP, in the Union Ministry of Environment, Forest and Climate Change, said that extremely hot weather combined with winds has led to the resuspension of coarse particles which is clearly visible in the high PM 10 values across most cities.

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“The rising temperatures during the heatwave have also pushed up the demand for air conditioning resulting in higher coal consumption and hence this is reflected in higher PM 2.5 levels,” said Prof Tripathi, who is also coordinator, National Knowledge Network in the Civil Engineering department of  IIT Kanpur.