Delhi’s air quality improved marginally, yet it was the most polluted city between October 1, 2022 and September 30, 2023, says the report
A list of the 10 most polluted cities in the last year showed that Delhi and other cities in the National Capital Region (NCR) still dominate air pollution rankings, according to a new report. Seven cities in the top 10 are in Delhi-NCR and Bihar, both part of the Indo-Gangetic Plain.
In this report by Respirer Living Sciences and Climate Trends, two sets of air quality data were analysed. The first is the government’s PM2.5 data for the past one year, i.e., October 1, 2022, to September 30, 2023, to track improvement in air quality over the previous year in NCR and other cities listed in the National Clean Air Programme (NCAP). The other is PM2.5 data during winter, roughly October–March when pollution levels rise. The period of study is from 2019 to 2023 in six major capitals known to have air quality challenges, which are Delhi, Mumbai, Kolkata, Bengaluru, Lucknow and Patna.
The report found that while Delhi’s air quality improved marginally, it was the most polluted city between October 1, 2022, and September 30, 2023, with a PM2.5 concentration of 100.1 micrograms/cubic metre (μg/m3 ). This is more than three times the government’s ‘good’ level and 20 times the WHO’s safe limit.
Patna, although in second place at 99.7 μg/m3, saw a 24% deterioration in air quality over the previous year. Seven cities in the top 10 are in Delhi-NCR and Bihar, both part of the IndoGangetic Plain.
A look at six major Indian Capitals, which have air quality challenges, during the peak pollution months (October–March) between 2019 and 2023 revealed that Mumbai’s AQ worsened steadily while Delhi’s and Lucknow’s improved.
When it comes to cleanest air in the country, the report found that Aizwal in Mizoram is the place with India’s cleanest air, with a PM2.5 level of only 11.1 μg/m3. It is followed by Chikkamagaluru in Karnataka (17.6 μg/m3 ) and Mandikhera in Haryana (17.7 μg/m3 ).
According to the report, Karnataka dominated the top 10 list of places with India’s cleanest air. However, the report also noted that a wider network of air quality monitors may well throw up many more such places.