Goldach (Switzerland): New Delhi has been ranked as the world’s most polluted capital city for the fourth consecutive year by a Switzerland-based air quality technology company IQAir.
The Indian capital is followed by Dhaka of Bangladesh), N’Djamena of Chad), Dushanbe of Tajikistan and Muscat of Oman, according to the IQAir World Air Quality Report released today.
It says that of the 15 most polluted cities in Central and South Asia in 2021, 12 were in India.
New Delhi saw a 14.6 percent increase in PM2.5 concentration in 2021, 96.4 μg/m3, up from 84 μg/m3 in 2020, the report said.
Annual PM2.5 concentration averages in 48 percent of India’s cities exceeded 50 μg/m3, or more than 10 times the WHO air quality guidelines, it said.
The IQAir said that stubble burning, which is common in the rice farms adjoining Delhi in the winter months, was responsible for up to 45 percent of pollution in the Indian national capital.
The assessment found that no country met the latest WHO air quality guidelines for PM2.5 in 2021.
The new WHO guidelines have effectively halved the acceptable amount of PM2.5 in the air (from a threshold of 10 ug/m3 down to 5 ug/m3,).
The report analyzes PM2.5 air pollution measurements from air monitoring stations in 6,475 cities in 117 countries, regions and territories.
IQAir’s 2021 World Air Quality Report is the first major global air quality report based on updated annual WHO air quality guidelines for PM2.5, it said in a statement.
The new guidelines were released in September 2021 and cut existing annual PM2.5 guideline values from 10 µg/m3 to 5 µg/m3.
Fine particle pollution, known as PM2.5, is commonly accepted to be the most harmful, widely-monitored air pollutant and has been found to be a major contributing factor to health effects such as asthma, stroke, heart and lung diseases.
PM2.5 leads to millions of premature deaths every year.