Delhi and Kolkata have the highest and second-highest levels of pollution globally in terms of Particulate Matter (PM) 2.5, according to the report titled Air Quality and Health in Cities released August 17, 2022.
Key highlights
- Delhi had an ‘annual exposure level’ of 110 microgram per cubic metre (µg/m³) which is 22 times the WHO benchmark of 5 micrograms per cubic metre. Kolkata came second with 84 µg/m³.
- The report has been published by the US-based research organisation Health Effects Institute (HEI) and released by HEI’s State of Global Air Initiative.
- The report provides a comprehensive and detailed analysis of air pollution and global health effects for more than 7,000 cities around the world.
- The analysis focussed on two of the most harmful pollutants — fine particulate matter (PM2.5) and nitrogen dioxide (NO2).
- The analysis used data from 2010 to 2019.
- The report found that exposure to PM2.5 pollution tended to be higher in cities located in low- and middle-income countries.
- Exposure to NO2 was found to be higher across cities in high-income as well as low- and middle-income countries. The reason for this is that NO2 is produced mainly from the burning of fuels mostly in older vehicles, power plants, industrial facilities and residential cooking and heating.
- In terms of NO2 exposure, Shanghai was the worst in terms of average exposure, and no Indian city was in the top 20.
- Shanghai had average NO2 exposure of 41.6 micrograms per cubic metre, followed by Moscow in Russia (40.2 micrograms per cubic metre).
- The WHO standard for NO2 exposure is 10 micrograms per cubic metre.
- The report said in 2019, exposure to pollutants in 86% of the more than 7,000 cities included in the report exceeded WHO’s standard, therefore impacting around 2.6 billion people.
- In terms of absolute numbers, the study attributed 29,900 deaths in Delhi in 2019 to be due to PM 2.5 exposure; 21,380 in Kolkata; and 16,020 in Mumbai. In comparison, Beijing saw 26,270 deaths in 2019 on account of PM 2.5 exposure.
