What is Behind Delhi’s ‘Poor’ Air Quality Year Round
The time between November to February is the chilling winter season for north India. It is the time when thick mufflers hide faces of the shivering people and chai shops become comfortable warm spots in the outdoors. But over the past decade, winter season in the northern Indian region has become the alleged season of ‘pollution’. It has become the season of choked nostrils and daily updates on AQI by newspapers. Even though toxic air is a reality for Delhi year round, the winters make it visible more disastrously. Factors from vehicular pollution, stubble burning, and faulty waste incineration to Diwali firecrackers are cited for the persistent toxic atmosphere not only in Delhi but also in other metropolitan areas across North India. For instance, the pollution levels in Chandigarh, India’s first planned city which is about 240km away from Delhi, have been at more than 15 times the safe limit recommended by the World Health Organization (WHO), for more than a month now. Each year in November, the Supreme Court passes orders directing various authorities to take serious measures. Special boards on pollution control work along with the municipal departments of various cities to work out a plan beforehand to control pollution. However, the problem remains unbattered year after year. The AQI hits an abnormally high record every year, which makes the people of the entire country go in awe. But the real question is, what is this pollution in North India that persists year on year in spite of multiple measures by various authorities, pressure groups and NGOs? There are many factors that contribute to the pollution in Delhi, and subsequently in the northern part of India. Amongst these, vehicular pollution and dust from construction work contribute the most to the annual poor air quality in Delhi year-round. Other factors include open waste burning, power plants in the region encompassing Delhi, agricultural burning of stubble and festivals that call for firecracker burning. Each one of these factors is taken care of by a separate governing body or control board in Delhi. This makes for multiplicity in the governance of a single problem. 1. AQI and Its Components The AQI or the air-quality index is a measure for reporting daily air-quality in a particular area. It defines how clean or polluted the air is and helps to predict pollution’s health effects on the human body. AQI is basically the measure of the density of pollutants present in the air. Eight individual pollutants are monitored to calculate a single composite index. These pollutants are namely PM10, PM2.5, nitrogen dioxide, sulphur dioxide, carbon monoxide, ground-level oxygen, ammonia and lead. Each pollutant has its own sub-index value, which cumulatively forms the bigger index or the AQI. The oxides of nitrogen and carbon monoxide make up 80% of Delhi’s air pollution, which mainly stems from traffic. 1.1 Year-On-Year Comparison The mean average of month-wise daily AQI for Delhi was released by the Press Information Bureau, which recorded the AQI from 2018 to 2023. These trends clearly show that AQI for 2023 between the months of November to February has seen an increment, in comparison to the last few years. 2. Factors 2.1 Vehicular Emissions The Centre for Science and Environment or CSE is a Delhi-based research and advocacy group that writes on critical environmental issues. The organisation stated, “While meeting the clean air benchmark requires deep cuts in emissions from all sources of pollution in the region, the mobility crisis will require immediate attention and upscale intervention to cut down the prime contributor to the toxic pollution buildup.” Vehicle emissions contribute up to 51% to the local pollution of Delhi. Delhi’s registered vehicle population has reached up to 7.6 million in recent times from 2.2 million back in 1994. This makes for a growth rate of 14% in vehicle registration per annum. Among these, two-thirds of the motor vehicles registered are two-wheelers. Residents in Delhi are pushing themselves towards private vehicles because of the lack of a robust public transport system. This makes one household own more than two cars. This is how vehicular pollution became one of the biggest contributing factors to Delhi’s poor air. Delhi started to implement fuel-based standards before any other city in the rest of the country. The BS2 standards were introduced in Delhi in 2001 and were rolled out in the rest of the country in 2005. The Delhi government also attempted the odd-even experiment up to 3 times till 2024, with its first attempt in January 2016. The rules restricted vehicles with registration numbers ending with an odd digit on odd days and an even digit on even days. But that did not render a lot of noticeable difference to the worsening air quality. This rule excluded Delhi’s large and old fleet of DTC buses and the huge number of two-wheelers. The myth that CNG buses were a cleaner option for transport in Delhi was busted by a real-world vehicle emission study by ICCT released in 2024, which stated that CNG buses emit oxides of nitrogen, which contribute to the formation of secondary PM and ozone.