The previous part discussed how air pollution and climate change are deeply connected, how extreme events around the world reveal this dangerous cycle, and how global warming continues to magnify pollution levels in ways that affect ecosystems, economies, and human lives.

This part of the article focuses entirely on the Indian scenario. If you are reading this article and would like to understand the global context before continuing, you can read Part 1 here. Part 2 will explore how this crisis affects public health, the economy, agriculture, infrastructure, and daily life. It will also discuss the progress India has made, the challenges that remain, and the strategies required to break the cycle of pollution and climate stress.

India’s Silent Struggle with Air Pollution

India, a land celebrated for its kaleidoscope of cultures, languages, and traditions, where the vibrant festivals and bustling streets captivate the world’s imagination, now grapples with an invisible crisis. The air that carries the chants of ancient prayers, the songs of celebration, and the hum of everyday life has become a source of concern. Air pollution has emerged as a formidable challenge, overshadowing the nation’s achievements and threatening the health of its people.

Despite being the 7th largest country in the world, blessed with vast landscapes and natural beauty, India holds the troubling distinction of being the 3rd most polluted country globally, according to the World Air Quality Report. This stark contrast highlights the paradox, while India’s size represents its vast potential, its position among the most polluted nations underscores the urgent need to address the deteriorating air quality. From the bustling metropolises of Delhi and Mumbai to the quieter rural landscapes, air pollution does not discriminate, it impacts millions, jeopardizing public health, economic growth, and environmental stability.

The Year-Round Reality of Air Pollution in India

Many people in India associate air pollution mainly with winter and events like Diwali due to the visible smog from firecrackers. However, air pollution is a year-round crisis. According to the World Air Quality Report 2023 by IQAir, 22 of the world’s 30 most polluted cities are in India. The causes are not just seasonal but stem from unchecked urbanisation, traffic congestion, unpaved roads, industrial emissions, and constant construction activities.

One of the A major contributors is the construction sector, which contributes up to 30 per cent of the total PM10 emissions in urban areas. Construction activities release large amounts of PM10 and PM2.5 particulate matter small enough to penetrate deep into the lungs and bloodstream. Much of this pollution arises from uncovered stockpiles of sand, soil, and other construction materials that are easily dispersed by wind, along with the constant movement of vehicles on and around construction sites that resuspend dust. Additional sources include material loading and unloading, cutting, grinding, drilling, cement mixing, and other construction processes that release fine particulate matter into the surrounding environment. These particles also originate from demolition activities, and the operation of earth-moving machinery. Without effective dust suppression and monitoring practices, these activities significantly deteriorate local air quality, especially in densely populated urban areas.These particles originate from cement mixing, cutting of tiles and stone, drilling, demolition, and earth-moving machinery. PM2.5 is especially dangerous because it can bypass the body’s natural filters and has been linked to lung cancer, strokes, and heart disease.

Unpaved roads further add to this burden. India has more than 1.7 million kilometers of roads, and even in cities, poorly maintained stretches contribute to resuspended road dust, which accounts for nearly 40 percent of PM10 in some cities. During dry periods, each vehicle movement lifts fine particles into the air, creating persistent dust clouds that can linger for hours.

Vehicle emissions are another major contributor after industrial pollution. India has over 360 million registered vehicles, and the number continues to grow. These vehicles release nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and PM2.5, all of which significantly impact urban air quality. The problem worsens with the use of outdated engines, poor traffic management, and idling vehicles in congested areas.

Stubble burning in states like Punjab and Haryana adds a seasonal spike to this ongoing issue. Each year, between significant amount of crop residue is burned in North India, releasing large volumes of PM2.5, carbon monoxide, and VOCs (volatile organic compounds). According to NASA satellite data, this pollution travels to cities like Delhi, where winter temperatures trap it close to the ground, worsening air quality. For example, Delhi’s Air Quality Index (AQI) often crosses 400 (severe) during these months, far above the safe limit of 100.

Understanding AQI

Air Quality Index or AQI is a metric that is widely used throughout the world to convert the concentration of various pollutants such as PM2.5, PM10, NO2, O2, CO etc. in the air  into an easy to understand index. In India, this index is defined as NAQI (National Air Quality Index) and has a value between 0-500 with 0 being the safest and 500 being the most severe based on the value of the most dominant pollutant.

A look at CPCB’s Daily AQI Bulletin provides a good view on the dominant pollutant in the country, which is almost always PM2.5 or PM10 for most of the Indian cities, besides O3, CO and NO2 for some other cities.

Regional Air Quality Analysis: AQI Trends

As India grapples with the escalating challenge of air pollution, the variation in Air Quality Index (AQI) across states and union territories highlights the complexity of this crisis. The AQI levels serve as a stark reminder of the urgent need for collective action to mitigate pollution and protect public health.

Following is the AQI range and AQI Category chart:

The graphs below illustrate AQI values across Indian states and union territories, revealing significant disparities in air quality. While some regions maintain satisfactory air, others face hazardous pollution levels, impacting millions of lives.

In states like Nagaland, Sikkim and Kerala, AQI values fall within the "Good" or "Satisfactory" range, indicating minimal or moderate health impacts. These regions benefit from lower population density, better vegetation cover, or stringent pollution control measures. On the other hand, states like Haryana and Uttar Pradesh report AQI levels in the "Poor" category, with hazardous health impacts for both sensitive groups and the general public.

A similar trend is observed across union territories. While Jammu and Kashmir report cleaner air with AQI values in the "Good" category, Delhi, the national capital, emerges as a hotspot of pollution with AQI levels breaching the "Hazardous" threshold. This disparity reflects the intensity of industrial activities, vehicular emissions, and population pressures in urban hubs like Delhi.

These AQI patterns reflect how pollution behaves differently across regions. This variation is shaped not only by emission sources but also by how air circulates, settles, and gets trapped within a specific geographical zone known as an airshed. Local climate conditions, wind flow, temperature, topography, and soil characteristics all influence how long pollutants remain suspended in the atmosphere.

Delhi is a clear example of this phenomenon. The National Capital Region lies in a landlocked basin with very limited natural ventilation. During winter, slow surface winds and frequent temperature inversion trap pollutants close to the ground. The surrounding Indo-Gangetic Plains also contribute to high dust resuspension due to their dry soil and agricultural activity. When combined with emissions from vehicles, industry, construction dust, and seasonal stubble burning, the region’s geographic and climatic characteristics result in consistently high AQI levels as shown in the graph above. 

Because each airshed functions differently, India requires region-specific clean air strategies that respond to local conditions. Improving air quality goes beyond reducing AQI numbers; it is essential for safeguarding public health and building a more sustainable environmental future.

Health and Environmental Impacts of Air Pollution and Climate Change

Air pollution not only drives climate change but also poses serious health risks. Due to climate change, rising temperatures have led to a surge in heat-related deaths, particularly during extreme heatwaves. Vulnerable populations such as the elderly, children, and those with pre-existing conditions are at higher risk. In contrast, climate change also contributes to more severe cold events, leading to hypothermia and cold-related fatalities. This dual threat of extreme heat and cold underscores the urgent need for public health adaptation strategies.

Health Impacts:

Air pollution is linked to a variety of health issues. Fine particulate matter (PM2.5), which can enter the lungs and bloodstream, causes respiratory and cardiovascular diseases such as asthma, bronchitis, lung cancer, and heart attacks. Long-term exposure increases the risk of premature death. Nitrogen oxides (NOₓ) and sulfur dioxide (SO₂) irritate the eyes and lungs, worsening respiratory conditions. Ground-level ozone, a key smog component, can impair lung function, especially in sensitive individuals.

Several statistical measures have been floated to raise awareness on the long term impact of pollution. A research backed rule of thumb floated by Berkeley Earth suggests exposure to 22μg/m³ (AQI of 37) equates to 1 cigarette a day. Another research by Energy Policy Institute of University of Chicago suggests excessive PM2.5 pollution is cutting life in India down by 3.5 years, this number is 8.2 years for Delhi.

Environmental Impacts:

Air pollution has far-reaching impacts on biodiversity, ecosystems, and agriculture, both globally and in India. Acid rain, caused by sulfur dioxide (SO₂) and nitrogen oxides (NOₓ), damages forests, soil, and water bodies, altering ecosystems and threatening aquatic and terrestrial life. Globally, biodiversity hotspots like the Amazon and Great Barrier Reef are under threat. Airborne pollutants contribute to coral bleaching in reefs and habitat loss in rainforests, jeopardizing species like jaguars, sloths, and coral-dependent marine life.

In India, air pollution severely affects biodiversity-rich regions like the Western Ghats and Himalayan foothills, where deforestation and industrial emissions lead to habitat loss and species decline. Acid rain and ozone pollution also reduce agricultural productivity by damaging crops such as wheat and rice. Studies show that India loses up to 14% of its annual crop yield due to ground-level ozone and particulate matter. Forests across India suffer reduced growth rates and vitality due to the deposition of pollutants, weakening ecosystems and threatening plant and animal species alike. These impacts underscore the urgent need for policies addressing pollution at both local and global scales.

Conclusion and Solutions

Air pollution is a critical issue, not just for its immediate health and environmental impacts but also for its long-term implications on ecosystems and climate. However, addressing air pollution is achievable with sustained effort and policy action. A notable example is China, once among the most polluted nations globally. Through widespread monitoring, stringent regulations, investment in renewable energy, shutting down heavily polluting industries, and improving urban infrastructure, China reduced its PM2.5 levels by nearly 40% between 2013 and 2020, as highlighted in multiple studies.

India can draw lessons from such success stories. Solutions include:

1. Strengthen Policy, Governance & Enforcement: Enforce strict emission norms for industries, thermal power plants, and vehicles, supported by real-time monitoring and frequent inspections.
2. Improve Urban Infrastructure & Reduce Dust Pollution: Fix and pave unpaved roads, maintain existing roads, and adopt mechanical sweeping and regular water sprinkling.Mandate cleaner construction practices, including dust barriers, covered material transport, and strict compliance with C&D Waste Management Rules.
3. Promote Alternatives to Stubble Burning: Provide farmers with viable and affordable alternatives through subsidies for residue management equipment like Happy Seeders and Super-SMS. Expand adoption of bio-decomposer solutions and create community-level machinery banks and crop-residue collection centers.
4. Accelerate Renewable Energy Transition: Expand solar, wind, and decentralized renewable energy systems to reduce dependence on coal-based power plants. Improve grid reliability to reduce diesel generator use and encourage rooftop solar adoption in urban and rural areas.
5. Shift to Clean Mobility: Promote electric mobility, strengthen public transport, and expand CNG/PNG distribution networks in non-attainment cities. Phase out older polluting vehicles and implement effective vehicle scrappage incentives.
6. Strengthen Waste Management Practices: Eliminate open burning of municipal solid waste by improving segregation, recycling, composting, and scientific landfill operations.
7. Enhance Green Cover and Urban Resilience: Expand urban plantations and biodiversity parks using native, high pollutant-absorbing species, particularly around traffic corridors and industrial zones.
8. Public Awareness and Behavioral Change: Conduct sustained awareness campaigns to educate people about health impacts of air pollution throughout the year; not only during winter smog episodes. Encourage citizen participation in reporting pollution, reducing household emissions, and adopting cleaner lifestyles.
9. Regional Coordination & Long-Term Planning: Strengthen cross-state cooperation, especially across the Indo-Gangetic region, to manage shared sources of pollution such as agricultural burning and industrial emissions.
10. Promote Widespread Monitoring & Targeted Action: Strengthen monitoring with the help of IT, governance and new low cost laser sensing technologies for real time source identification and remedial action.
11. Use of Technology for Pollution Abatement at Source: Use of new technology such as exhaust air scrubbing, dust precipitation, molecular filtration, catalytic conversion etc to minimise air pollutant generation from source.

Adopting a multi-pronged strategy inspired by global examples like China’s success, India can improve its air quality and safeguard public health and the environment for future generations.

Authored By - Mijul Saxena, Shivani Rani and Anurag Bajpai

Reviewed By - Sandeep Narang and Neeraj Kumar

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