Not even one country met WHO air quality standards in 2021, India 5th most polluted country: Report
The data, compiled by IQAir, a Swiss company that monitors air quality, shows that while no countries met the standards in 2021, only 3.4 per cent of the surveyed cities did
A survey of pollution data from 6,475 cities showed that no country managed to meet the World Health Organization's (WHO) air quality standard in 2021, and smog even rebounded in some regions after a COVID-related dip.
The data, compiled by IQAir, a Swiss company that monitors air quality, shows that while no countries met the standards in 2021, only 3.4 per cent of the surveyed cities did. Based on air quality data from 6,475 cities in 117 countries, the report presents an overview of global air quality in 2021.
At least 93 cities recorded PM2.5 levels that were 10 times higher than what WHO recommended.
Since changing its guidelines last year, the WHO recommends that average annual concentrations of hazardous airborne particles known as PM2.5 be no more than 5 micrograms per cubic metre. However, the WHO stresses that even low PM2.5 concentrations are harmful.
"There are a lot of countries that are making big strides in reduction," IQAir science manager Christi Schroeder said.
"China started with some very big numbers and they are continuing to decrease over time. But there are also places in the world where it is getting significantly worse."
The data showed that India's overall pollution levels worsened in 2021 and that New Delhi remained the most polluted capital in the world.
It was also revealed that 35 of the 50 cities with the worst air quality are in India, the country is ranked as the fifth most polluted country.
"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."
As in the previous year, Bangladesh was the most polluted country, while Chad ranked second after the African nation's data was included for the first time.
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China fell to 22nd place in the PM2.5 rankings in 2021, down from 14th place a year earlier with an average reading of 32.6 micrograms over the year, according to IQAir.
Hotan in Xinjiang's northwestern region is China's worst-performing city, with an average PM2.5 level reading of over 100 micrograms, due primarily to sandstorms.
After being overtaken by two Indian cities, Bhiwadi and Ghaziabad, it dropped to third on the top polluted cities list.