The Centre for Science and Environment (CSE), a New Delhi-based public interest research and advocacy organisation, has conducted an investigation into air quality trends across northern India, specifically focusing on cities outside Delhi and the National Capital Region (NCR). Their analysis reveals that during winter, as pollution spikes, the entire region is affected by smog episodes.
Understanding Particulate Matter
Particulate Matter (PM) is a mixture of solid particles and liquid droplets found in the air, often emanating from sources such as construction sites, fields, fires, and smokestacks. It includes PM 2.5, fine particulate matter smaller than 2.5 micrometres in diameter, and PM10, inhalable particles generally 10 micrometres and smaller.
CSE’s Analysis Methodology
The examination carried out by CSE focused on understanding the synchronised pattern of pollution during winter. It covered 137 continuous ambient air quality monitoring stations (CAAQMS) spread across 56 cities in six states. The CAAQMS assists in real-time monitoring of Air Pollution, including particulate matter, throughout the year. The data for the analysis was sourced from the Palam weather station of the India Meteorological Department (IMD), National Aeronautics and Space Administration (NASA)’s Fire Information for Resource Management System, specifically the Visible Infrared Imaging Radiometer Suite (VIIRS), and other reliable sources.
Insightful Findings
The study disclosed that most smaller towns have lower annual average PM2.5 levels, but during winter, these towns experience pollution levels comparable to Delhi. Atmospheric changes like inversion, calm conditions, change in wind direction, and seasonal drop in ambient temperature entraps pollution across north India. This is further triggered into a severe category by smoke from farm fires and Diwali firecrackers during November.
Air Quality Status across Cities
Delhi and NCR cities topped the chart for the most ‘severe’ air quality days in 2021. The study also pointed out that while all of north India is vulnerable to pollution build-up, the annual average of Delhi and NCR is among the highest in the region. Industrial towns remain vulnerable throughout the year despite the monsoon reducing overall pollution in the region.
The Problem of Farm Fires
Farm fires are one of the biggest drivers of pollution during the winter season. The analysis revealed that intensity of Fire Radiative Power (FRP), which indicates the volume of biomass burned, is a key contributor to increased PM levels during winter. It showed that Punjab has the maximum number of fires after Haryana, UP, Rajasthan and Delhi.
Nitrogen Dioxide Levels
There has been a significant increase in the levels of Nitrogen dioxide (NO2) in air during November compared to other months. NO2, which comes almost entirely from combustion sources and significantly from vehicles, contributes greatly to the pollution load.
Diwali – A Mega Pollution Event
Despite restrictions on bursting firecrackers, Diwali continues to be a mega pollution event with toxicity levels rising sharply during this period.
Undertaken Initiatives to Control Air Pollution
Several initiatives have been undertaken to control air pollution, such as the Commission for Air Quality Management in National Capital Region (NCR) and Adjoining Areas, implementation of Bharat Stage (BS) VI norms, creation of a Dashboard for Monitoring Air Quality, launch of National Clean Air Programme, introduction of National Air Quality Index (AQI), enforcement of Air (Prevention and Control of Pollution) Act, 1981, and execution of Pradhan Mantri Ujjwala Yojana (PMUY).
The Way Forward
The findings cast a spotlight on the problem of winter pollution across major northern Indian states. They show that smaller cities, which typically have lower annual average pollution, experience high pollution levels during winter, often worse than Delhi. Such evidence emphasizes the need for harmonised action across all states to ensure access to clean fuels and technology in industry and power plants, massive scaling up of public transport, walking and cycling infrastructure, and enhanced municipal services for complete segregation of waste and recycling.