Delhi's Air Pollution: Who's To Blame?

Delhi, the capital territory of India, has been dubbed the most polluted city in the world, with toxic air pollution levels that are locked in by changing weather conditions. The causes of Delhi's air pollution are complex and multifaceted, ranging from anthropogenic to natural sources. Vehicular emissions, industrial pollution, crop stubble burning, construction, road dust, and overpopulation all contribute to the poor air quality. The Indian government has attempted to address the issue through various measures, such as closing schools and offices, banning highly polluting vehicles, and implementing emergency restrictions. However, the severity of Delhi's air pollution persists, posing severe health risks to its residents and requiring more comprehensive and effective solutions.

Delhi is the most polluted city in the world

Delhi, the capital territory of India, is the most polluted city in the world. In August 2022, a survey of 7,000 world cities by the US-based Health Effects Institute found that Delhi's air pollution was the worst of any major city. The air pollution in Delhi also affects the surrounding districts. India has the world's highest death rate from chronic respiratory diseases and asthma, according to the World Health Organization. In Delhi, poor air quality has irreversibly damaged the lungs of 2.2 million children.

Delhi's air quality index (AQI) often falls within the \"Unhealthy\" or \"Poor\" ranges, and during the winter months of October to February, it routinely eclipses 700, posing severe health risks. The primary sources of air pollution in Delhi include vehicular emissions, industrial pollution, crop stubble burning, thermal power plants, road dust, and construction.

Stubble burning is a significant contributor to Delhi's air pollution. Farmers burn the leftover crop stubble after harvesting rice to quickly and cheaply clear the fields for the next crop. While this practice was made illegal in 2015, it still continues, and the wind blows the smoke from these fires into Delhi, where meteorological conditions often trap the smoke over the city.

To combat air pollution in Delhi, the government has implemented various measures, including the formation of the Commission for Air Quality Management to enforce pollution control, a Pollution Control Team that regulates dust and bans diesel generators in select areas, and farming incentives to encourage alternative crops and reduce stubble burning. Additionally, smog towers have been installed across Delhi to clean the polluted air, and the Pusa Bio-Decomposer has been introduced to manage crop residue and reduce stubble burning.

Despite these efforts, Delhi continues to struggle with severe air pollution, and in November 2024, the city recorded its worst air quality of the season, with an AQI reading of 491, classified as "severe plus." The air pollution in Delhi has severe health impacts, and the crisis persists as a public health emergency.

Stubble burning, vehicular emissions, and industrial pollution are major contributors

Delhi, the capital territory of India, has been dubbed the city with the worst air pollution of any major city in the world. The city's poor air quality has been linked to irreversible lung damage in 2.2 million children. The air pollution in India is estimated to kill about 2 million people annually and is the fifth-largest killer in the country.

Secondly, vehicular emissions are a major contributor to Delhi's air pollution. In a collaboration between the Delhi government and IIT-Kanpur, it was found that vehicular emissions contributed approximately 38% of the capital's air pollution on a particular day. India's Ministry of Earth Sciences also attributed almost 41% of air pollution to vehicular emissions in a 2018 research paper. During winters in Delhi, unfavourable meteorological conditions can exacerbate the impact of vehicular emissions on air quality.

Lastly, industrial pollution has significantly contributed to Delhi's air pollution. As an industrial region, unplanned industrial development, increasing traffic, and high energy consumption have led to high levels of air pollutants in the city. Studies have found strong associations between air pollutants in industrial areas and respiratory diseases among industrial workers and their families. The increase in industrialization and the consequent rise in air pollutant concentrations have posed significant health risks to Delhi's population.

Other factors contributing to Delhi's air pollution include animal agriculture, firecrackers during festivals, thermal power plants, road dust, and construction activities. Addressing these diverse sources of air pollution is crucial to improving the city's air quality and reducing its severe health impacts on residents.

Air pollution causes severe health issues

Delhi, the capital territory of India, has been found to be the most polluted city in the world, with air pollution levels that routinely pose severe health risks. In 2022, the air pollution in Delhi was deemed the worst of any major city in a survey of 7,000 world cities by the US-based Health Effects Institute.

Air pollution in India is estimated to kill about 2 million people every year and is the fifth-largest killer in the country. India has the highest death rate from chronic respiratory diseases and asthma, according to the World Health Organization. In Delhi alone, poor air quality has irreversibly damaged the lungs of 2.2 million children.

The sources of air pollution in Delhi are varied. According to India's Ministry of Earth Sciences, vehicular emissions contribute to almost 41% of air pollution, with vehicle pollution being a significant factor in the high levels of nitrogen oxides in the city. Industrial emissions account for 18% of air pollution, with 90% of Delhi's sulfur dioxide emissions stemming from factories and power plants. The burning of crops in nearby states has also contributed to Delhi's pollution problem since the 1980s, with farmers burning their crops to clear fields. This practice, known as stubble burning, was responsible for 38% of Delhi's pollution in 2023.

The health impacts of air pollution are far-reaching and severe. Fine particulate matter, such as PM2.5 and PM10, can cause serious health issues. Smaller particles with a diameter of 2.5 microns or less can penetrate the lung barrier and enter the bloodstream, affecting all major organs. These pollutants increase the risk of heart and respiratory diseases, lung cancer, and strokes. They can also worsen asthma and cause bronchial symptoms, lung inflammation, and reduced lung function. Ozone, a major component of smog, is formed through the combustion of fossil fuels and is a well-established respiratory irritant. Short-term exposure can cause chest pain, coughing, and throat irritation, while long-term exposure is linked to decreased lung function and chronic obstructive pulmonary disease. Sulfur dioxide, another byproduct of burning fossil fuels, causes eye irritation, worsens asthma, and impacts the cardiovascular system.

The effects of air pollution extend beyond physical health, with recent studies indicating impacts on mental health and worker productivity. Children are particularly vulnerable to the toxicological impacts of air pollution, with higher PM2.5 exposure impairing brain development. Globally, lower respiratory infections are the second leading cause of death for children under five years, and air pollution is the foremost environmental factor contributing to these deaths.

The government has implemented action plans to combat air pollution

Delhi, the capital territory of India, has been ranked as the most polluted city in the world. Air pollution in India is estimated to kill about 2 million people annually and is the fifth-largest killer in the country. India also has the highest death rate from chronic respiratory diseases and asthma, according to the World Health Organization.

To combat this issue, the government has implemented various action plans. In November 2021, the Delhi government shut down schools and government offices for a week due to severe air pollution. The Supreme Court of India urged the central and state governments to take strict measures to reduce pollution in Delhi and the NCR region. In response, the government formed the Commission for Air Quality Management (CAQM) to enforce pollution control in the NCR. A 10-member Pollution Control Team managed complaints through the "Green Delhi" app, regulated dust, and banned diesel gensets in select areas.

The government has also implemented farming incentives, such as the MSP scheme for alternative crops in Punjab, to reduce stubble burning, a major contributor to air pollution. The Supreme Court further urged Punjab to revisit the 2009 water law, which contributes to late paddy sowing and stubble burning. The Graded Response Action Plan (GRAP) categorizes air quality into four stages, triggering stricter pollution control measures, including a ban on waste burning, dust control at construction sites, and road cleaning.

Additionally, the government has launched a 21-point Winter Action Plan, including real-time monitoring of pollution using drones, deploying special task forces, and implementing emergency measures such as artificial rain and vehicle rationing. The plan also includes an anti-dust campaign and a focus on public participation. The Delhi government has also imposed a complete ban on the sale and use of firecrackers, contributing to a significant reduction in air pollution during Diwali.

Furthermore, the government has installed smog towers, such as the one at Connaught Place, to clean the polluted air. The Pusa Bio-Decomposer is also being used to reduce stubble burning by managing crop residue. The Delhi government has formed teams to inspect construction sites, control dust pollution, and monitor industrial sites to ensure the use of clean and authorized fuel. These measures demonstrate the government's efforts to address the critical issue of air pollution in Delhi and improve the health and well-being of its citizens.

Solutions include smog towers, air purifiers, and farming incentives

Delhi, the capital territory of India, has been dubbed the city with the worst air pollution of any major city in the world. The air pollution in Delhi is so severe that it has irreversibly damaged the lungs of 2.2 million children. The leading causes of air pollution in Delhi are vehicular emissions, dust, industrial emissions, and agricultural practices.

To combat this pressing issue, several solutions have been proposed and implemented, including the use of smog towers, air purifiers, and farming incentives. Smog towers are structures designed to filter and purify the air, capturing particulate matter and pollutant gases. While the effectiveness of smog towers in Delhi is yet to be determined, they have been implemented in other cities with positive results.

Air purifiers, on the other hand, have gained popularity among residents of Delhi. Pulmonologists recommend the use of air purifiers with high-efficiency particulate air (HEPA) filters, which can capture up to 99.97% of particles as small as 0.3 microns. These filters are particularly beneficial for individuals with respiratory issues, allergies, or asthma, as they reduce allergens, irritants, and volatile organic compounds (VOCs) in the air. However, it is important to note that air purifiers are most effective when used consistently and with proper maintenance, including regular filter replacements.

In addition to technological solutions, policy interventions have been explored to address agricultural contributions to air pollution. One approach is the implementation of Payment for Ecosystem Services (PES) contracts, which provide cash transfers to farmers on the condition that they refrain from burning crop residue. This strategy has been tested in randomized controlled trials, showing promising results in reducing the widespread practice of crop burning.

Another proposed solution is the creation of a 1,600 km long and 5 km wide green ecological corridor along the Aravalli Range from Gujarat to Delhi, connecting to the Sivalik Hills range. This initiative involves planting 1.35 billion new native trees over ten years, aiming to combat pollution and improve air quality.

While these solutions offer potential avenues to mitigate air pollution in Delhi, a comprehensive approach that addresses multiple sources of pollution and engages various stakeholders is necessary to bring about significant and lasting improvements in air quality.

Frequently asked questions