Aizwal, Mizoram In India Has Cleanest Air

Aizwal, Mizoram, is the place with India’s cleanest air, with a PM2.5 level of only11.1 μg/m3. While A list of the 10 most polluted cities in the last year shows that Delhi and other cities in the National Capital Region (NCR) still dominate air pollution rankings.

Delhi’s air quality improved marginally, yet it was the most polluted city between 1 October 2022 and 30 September 2023, with a PM2.5 oncentration of 100.1 micrograms/cubic metre (μg/m3). This is more than thrice the government’s ‘good’ level and 20 times the WHO’s safe limit.

A look at six major capitals, which have air quality challenges, during the peak pollution months (October–March) between 2019 and 2023 shows that Mumbai’s AQ worsened steadily while Lucknow’s improved. Patna, though in second place at 99.7 μg/m3 , saw a 24 per cent deterioration in air quality over the previous year.

Data for the top 10 polluted cities and six major capitals shows that both annual and quarterly PM2.5 levels in all these places were higher than the Central Pollution Control Board’s ‘good’ level of 30 μg/m3 and WHO’s safe guideline of 5 μg/m3.

This data was released by AirPollutionRanking by RespirerReports . Respirer Reports, an initiative of Respirer Living Sciences. In this report, Respirer Reports, an initiative of Respirer Living Sciences, analyses two sets of air quality data. The first is the government’s PM2.5 data for the past one year,i.e., 1 October 2022 to 30 September 2023, to track improvement in air quality over the previous year in NCR and other cities listed in the National Clean Air Programme(NCAP).

Two regions dominate the top 10 list of polluted cities in India from 1 October 2022 to30 September 2023 – Delhi-NCR and Bihar. There are five NCR cities, Delhi, Faridabad, Ghaziabad, Noida and Meerut, and in Bihar, Patna and Muzaffarpur. The list also has Nalbari in Assam, Asansol in West Bengal, and Gwalior in Madhya Pradesh. Currently, Nalbari and Asansol have only one air quality monitor each, while Gwalior has three monitors that record the NCAP data. Since NCAP’s launch in January 2019, the government has consistently added Continuous Ambient Air Quality Monitoring Stations (CAAQMS), from about 200 then to 517 currently.

The other is PM2.5 data during winter, roughly October–March when pollution levels rise. The period of study is from 2019, when NCAP was launched, to 2023 in six major capitals known to have air quality challenges. These are Delhi, Mumbai, Kolkata, Bengaluru, Lucknow and Patna.

City Oct-Dec 2019 Oct Dec 2020 Oct-Dec 2021 Oct-Dec 2022

Monitors recorded data for >70 per cent of the time for all years.

PM2.5 (fine particulate matter) data is a widely used measure for assessing the impacts of air pollution on health. The data is available through NCAP, which aims to reducePM2.5 and PM10 concentrations in Indian cities by 40 per cent of 2017 levels by 2026. PM2.5 refers to air particles that are 2.5 microns in diameter, which is approximately 1/30th the width of a strand of human hair. It consists of fine, toxic particles that can penetrate deep into the lungs, enter the bloodstream and cause heart disease, stroke and other respiratory diseases.

The writer of this article is Dr. Seema Javed, an environmentalist & a communications professional in the field of climate and energy