World Air Quality report 2021: Delhi most polluted capital city in the world

New Delhi has emerged as the most polluted capital city in the world, according to the latest World Air Quality Report for 2021. New Delhi is followed by Dhaka (Bangladesh), N’Djamena (Chad), Dushanbe (Tajikistan), and Muscat (Oman). The report found that no country met the World Health Organization’s (WHO) PM2.5.

India’s average pollution levels reached 58.1 µg/m3 in 2021, which ended a three-year trend of improving air quality.

“India’s annual average PM2.5 levels reached 58.1 µg/m3 in 2021, ending a three-year trend of improving air quality. India’s annual PM2.5 averages have now returned to pre-quarantine concentrations measured in 2019,” read the report.

According to the report, India was home to 11 of the 15 most polluted cities in Central and South Asia in 2021 and 48% of India’s cities exceeded 50 µg/m3 which is more than 10 times the WHO guideline.

“India was home to 11 of the 15 most polluted cities in Central and South Asia in 2021. Delhi saw a 14.6% increase in PM2.5 concentrations in 2021 with levels rising to 96.4 µg/m3 from 84 µg/m3 in 2020. No cities in India met the WHO air quality guideline of 5 µg/m3. In 2021, 48% of India’s cities exceeded 50 µg/m3, or more than 10 times the WHO guideline,” the report said.

Air pollution has a massive impact on human health in India. It is the second biggest risk factor for disease, and the economic cost of air pollution is estimated to exceed $150 billion dollars annually.

Major sources of air pollution in India include vehicular emissions, power generation, industrial waste, biomass combustion for cooking, the construction sector, and episodic events like crop burning.

It is estimated that 20% to 35% of total urban PM2.5 concentrations are directly or indirectly due to internal combustion engines in motor vehicles.