DELHI: A surplus monsoon has brought down air pollution of Indian cities in ‘good’ to ‘satisfactory’ categories according to the standard set by National Ambient Air Quality Standards (NAAQS) in August.Moreover, no cities were under ‘poor’ to ‘severe’ categories. Delhi’s air was the cleanest in the past four years. However, 177 cities out of total 254 Indian cities in August recorded higher PM2.5 levels than the World Health Organization’s (WHO’s) daily guideline levels.India’s NAAQS set the annual average limits for PM2.5 at 40 µg/m³ and for PM10 at 60 µg/m³ whereas, WHO recommend annual average limits of 5 µg/m³ for PM2.5 and 15 µg/m³ for PM10.All of India’s megacities, including Delhi, Chennai, Mumbai, Kolkata, and Bangalore, maintained PM2.5 concentrations below the NAAQS throughout the month, with all days categorized as either ‘Good’ or ‘Satisfactory.’According to the analysis by the Centre for Research on Energy and Clean Air (CREA), in August 2024, a total of 218 Indian cities were categorized as ‘Good (0-30 µg/m³)’ on the AQI scale, while 26 cities were ‘Satisfactory (31-60 µg/m³)’ and only one city was ‘Moderate (61-90 µg/m³)’.Notably, no cities fell into the ‘Poor (91-120 µg/m³)’, ‘Very Poor (121-250 µg/m³)’, or ‘Severe (>250 µg/m³)’ AQI categories, highlighting the positive impact of the month’s rainfall on air quality. Delhi saw a significant improvement in air quality this August, with a monthly average PM2.5 concentration of 27 µg/m³. The city had 24 days categorized as ‘Good’ (0-30 µg/m³) and 7 days in the ‘Satisfactory’ range (31-60 µg/m³), marking this as the second cleanest August since 2016. The only cleaner August was in 2020, which saw an average of 25 µg/m³.“This improvement can be attributed to the 26 rainy days experienced throughout the month, which effectively washed away pollutants, contributing to cleaner air across the city,” said Manoj Kumar, a researcher with CREA.Meanwhile, Byrnihat in Assam ranked as the most polluted city in India, with a monthly average PM2.5 concentration of 78 µg/m³. Byrnihat has consistently been among the top 10 most polluted cities throughout the year, marking the fifth instance in 2024 where it claimed the top spot for the highest pollution levels.Cities in the list of top 10 most polluted cities in India were, Byrnihat, Sri Ganganagar, Araria, Mandi Gobindgarh, Samastipur, Jalna, Panipat, Gurgaon, Siwan, and Durgapur.
Source link
