An analysis of winter PM2.5 pollution levels in seven major Indian cities has shown that Varanasi was the only city that met national standards for this particulate matter in the last two years. This means that in the winters of 2022-2023 and 2023-2024, Varanasi met national standards set for levels of particulate matter with size less than 2.5 micrometres. Despite being a part of the Indo-Gangetic Plain, which is the most polluted region of India, Varanasi had the lowest winter pollution levels of all the seven major cities.
The analysis, conducted by Climate Trends, a research-based initiative that focuses on climate change, considered the period from October to February as winter. The air quality data was obtained from the Central Pollution Control Board (CPCB) website.
The seven major cities studied were Delhi, Mumbai, Varanasi, Patna, Chandigarh, Lucknow, and Kolkata.
Winter PM2.5 levels in the Indian cities other than Varanasi
In the winter of 2023-2024, Mumbai had PM2.5 pollution levels below the national standard.
Compared to 2022-2023, Delhi witnessed an increase in PM2.5 levels in the winter months of 2023-2024.
In all the cities except Chandigarh, pollution levels in January and February were lower than those from October to December, despite the fact that January and February are colder months.
Chandigarh was the second most polluted city in terms of winter PM2.5 levels during both years.
Mid-December and January were the most polluted months in Chandigarh.
In a statement released by Climate Trends, Dr Atenderpal Singh, Assistant Professor, Department of Environmental Studies, University of Delhi, said that future studies must focus on finding the sources of PM2.5 so that effective pollution mitigation strategies can be planned.
Which factors worsen winter pollution?
The factors which exacerbate winter pollution include temperature variations, increased emissions from heating sources, stagnant atmospheric conditions, and accumulating pollutants over time. Concentrations of PM2.5 and other pollutants increase as a result of these conditions.
Children, the elderly, and individuals with pre-existing health conditions are most susceptible to adverse health effects of winter pollution.
