New Delhi: The national capital has been declared the most polluted capital in the world for the fourth year in a row, according to the World Air Quality Report released Tuesday by Swiss organization IQAir. The report has been compiled based on PM2.5 data from 6,475 cities in 117 countries. It has been derived from IQAir real-time online air quality monitoring platform, which aggregates, validates, calibrates, and harmonizes data from air quality monitoring stations around the globe.
The researchers said, "India was home to 11 of the 15 most polluted cities in Central and South Asia in 2021. Delhi saw a 14.6 per cent increase in PM2.5 concentrations in 2021 with levels rising to 96.4 ug/m3 from 84 ug/m3 in 2020. No cities in India met the WHO air quality guideline of 5 ug/m3. In 2021, 48% of India's cities exceeded 50 ug/m3, or more than 10 times the WHO guideline."
Researchers have found that air pollution causes and aggravates many diseases, ranging from asthma to cancer, lung illnesses and heart disease. In times of COVID-19, exposure to PM2.5 increases both the risk of contracting the virus and suffering more severe symptoms when infected, including death.
The researchers further said the country's "annual average PM2.5 levels reached 58.1 ug/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." The report weighed that 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. Researchers also found that the air quality improved in China as more than half of the cities in the country included in the report saw lower levels of air pollution when compared to the previous year.
