But what’s really driving this crisis? Is it just the inevitable side effect of urban growth? Or is something deeper — and more systemic — at play?

Let's take a deep dive into the causes, stripping away the surface layer(s), and focusing on the roots of India’s air pollution problem. Spoiler alert: It’s not just about cars and factories. So why is the problem different, depending on where you live, and why a one-size-fits-all solution just won’t cut it.

Urban Expansion A Synonym For Pollution

Let’s start with the big one: Urbanisation. India is urbanising fast, but some smaller cities are now facing pollution levels that rival those of Delhi. Take Gwalior, for instance. Once known for its relatively clean air, Gwalior in 2024 recorded PM2.5 levels above 300 µg/m³. That’s more than 10 times the safe limit set by the World Health Organisation (WHO).

This is not an isolated incident. Other cities like Varanasi have also been seeing pollution levels hovering above 250 µg/m³ for months, which has had a cleaner record than some of the north eastern cities. 

This is because of a perfect storm: Rapid urban sprawl, unregulated industrial growth and a lack of infrastructure. Cities are growing so fast that they can’t keep up with the pollution. Imagine adding thousands of vehicles and factories without building enough roads or setting up pollution controls. It's a recipe for disaster and we’re seeing it play out in real time.

The Invisible Villains

It’s not just about urban sprawl. The industrial sector is also a major culprit. As India industrialises, factories, brick kilns and coal-fired power plants continue to spew out harmful particulate matter.

Industries are responsible for nearly 30 per cent of India’s air pollution, according to a 2023 report by the Centre for Science and Environment (CSE). As much as India is trying to make the switch to renewable energy, it’s still heavily reliant on coal, which is responsible for much of the pollution.

Take a look at Bhubaneswar and Ranchi. Historically, these cities have had slower industrial growth, but in recent years, they've seen an uptick in pollution due to new coal-fired power plants and expanding factories.

These power plants and factories are cranking out more than just particulate matter — they’re releasing sulfur dioxide and nitrogen oxides, which degrade air quality even further.

Cars, Cars and More Cars

India’s streets are getting more crowded with cars. Between 2020 and 2023, the number of vehicles in Indian cities grew by 12 per cent. While that’s great for the automobile industry, it’s terrible for air quality.

Inadequate emission compliance, oil deterioration and aged cars contribute to a calamitous trifecta. More than seven out of every 10 urban dwellers in India use vehicles, which has allowed cities like Chandigarh and Surat to repeatedly breach the pollution regulations established by the WHO.

Consider what happens when you add thousands of new cars to roads already choked with pollution from industrial emissions. You get a traffic monster that’s suffocating the cities. So, what can be done? Is the answer better public transport, stricter emission norms, or simply fewer cars on the road?

Sudhir Kumar, an urban air quality expert at IISc, suggests that the key to tackling urban pollution lies in improving public transportation and retrofitting existing vehicles with better emission technology. “We need a shift in policy,” says Kumar. “Without major changes in how we think about transportation, urban air quality will only continue to worsen.”

Rural India, The Silent Polluter?

We’ve mostly talked about cities, but rural India isn't off the hook. While urban areas are getting most of the attention, rural households are contributing to the pollution problem too.

About 85 per cent of rural households still rely on biomass fuels like firewood and agricultural waste for cooking. This leads to indoor air pollution, but the smoke doesn’t stay inside — it drifts out into the air, adding to the outdoor pollution crisis.

The Global Burden of Disease (GBD) study estimates that biomass burning is responsible for up to 25 per cent of India’s overall particulate pollution. That is a huge chunk. And it’s not just about cooking.

The poor air quality in rural areas leads to higher rates of respiratory and cardiovascular diseases. So, how do we solve this? More clean cooking technologies? Better access to alternative energy sources?

Rural India can’t be left behind if we want to clean up our air. Ramesh Sharma, a public health expert with the Indian Council of Medical Research (ICMR), explains, “Rural households are at the frontlines of air pollution, but their voices are often left out of policy discussions. Addressing the rural crisis will require targeted efforts to provide alternative fuels and increase healthcare access.”

The Governance Gap

Despite all these causes, there’s still no unified approach to tackle the problem. India has a National Clean Air Programme (NCAP), but its implementation has been inconsistent, with only 25 per cent of cities under the NCAP meeting WHO’s PM2.5 standards in 2022.

The Air Act of 1981, India’s primary air quality legislation, is outdated and doesn’t account for the modern complexities of pollution from vehicles and industries.

The question is, who is in charge of making sure that these air quality regulations are actually enforced? Unfortunately, the answer is not as clear as it should be. Fragmented governance at the local level is failing to bring together all the necessary players — government agencies, industry leaders and the public — under a cohesive strategy.

Should India Rethink Its Energy Sources?

Speaking of industries, India’s reliance on coal-powered electricity is a big part of the problem. More than 60 per cent of India’s electricity still comes from coal-fired power plants, and the pollution from these plants is wreaking havoc on air quality. While there are efforts to increase renewable energy sources, the slow pace of transition means coal is here to stay — for now, at least.

The long-term plan is somewhere between doubling down on renewables and cleaning up the coal industry. Experts like Arun Kumar, an energy policy analyst, warn that transition to cleaner energy needs to be much faster. “We cannot afford to wait decades for cleaner energy alternatives,” he says. “In the meantime, improving the efficiency of coal plants and reducing emissions is critical.”

Construction, Waste and the Growing Urban Jungle

In cities like Kanpur and Lucknow, unregulated construction activities, improper waste disposal and a lack of green spaces, are adding even more pollutants to the air.

In fact, these cities are seeing a rise in particulate matter largely as a result of construction dust and the absence of places where trees can filter out pollutants. As India’s cities grow, they might just suffocate under the weight of unchecked development. The lack of green infrastructure is a critical issue, and it’s one we can’t afford to ignore.

What’s Next?

India’s air pollution crisis is a multi-headed monster, and there’s no single solution. The causes are deeply rooted in urbanisation, industrial growth, outdated policies and a lack of enforcement. While cities like Beijing and Seoul have shown that change is possible, India has a long road ahead.

Suman Gupta, an environmental policy expert, suggests that the key lies in a comprehensive and integrated approach. “India needs a national framework that addresses urban, rural and industrial pollution, simultaneously,” Gupta argues. “We can’t afford to treat these as separate issues anymore.”

(The next part of "Breathing Unequal" will examine how the consequences of air pollution extend beyond health, reaching into economics, social inequalities and regional disparities)