Why Delhi’s air pollution is so hard to fix | Explained | Bbc News India

I feel like if I stay here for one month, I would be hospitalized. My eyes are burning light and becoming reddish. That's why I wear mask. There is a problem in breathing and you can see my eyes watering. We don't feel like coming out. My children can't breathe and grandchildren can't breathe. I mean, this is our capital city. Every year, it's the same story. As winter sets in, Delhi's skyline is engulfed by a thick layer of smog that experts call toxic. For Delhi's children, breathing this polluted air can have consequences that last well into adulthood. For its elderly, this toxic air can worsen existing heart and lung conditions, increasing the risk of serious illness and hospitalisation. Schools face restrictions, construction work is stopped, certain vehicles are banned and water is sprinkled in many parts of the city to control dust. Now Delhi has been fighting pollution for years. We know what its causes are. We have laws, restrictions and even a special body called the Commission for Air Quality Management or CAQM to tackle this. But Delhi's residents have seen little tangible relief from this toxic air. So why is it so difficult to clean Delhi's air? The first problem is the sheer number of sources polluting Delhi's air. Vehicles, construction dust, agricultural burning and waste burning all contribute. And how much each source contributes changes with the season. Now consider Dublin, the capital of Ireland. In 1990, it banned the sale of smoky coal, a major source of pollution, from home heating. Over the following six years, Dublin reported a 15.5% reduction in respiratory deaths. This shows how curbing one major source of pollution can improve air quality and public health. But for Delhi, it's not that simple. It has to tackle pollution from multiple different sources at the same time. Experts say all these sources of pollution need to be tackled together and with equal urgency. What's more, some sources are easier to regulate than others. Delhi has so many sources of pollution that tackling one or even several still leaves others contributing to the problem. Delhi's pollution problem is not just about what goes into the air. It's also about what happens to that polluted air afterwards. And this is where Delhi's weather and its geography make things worse. Delhi lies in the Indo-Gangetic plain with the Himalayas to its north. During winter, wind speeds weaken, air becomes dense and the region's geography can make it harder for pollution to disperse. The result? Delhi doesn't necessarily need to produce more pollution for its air to become more dangerous. The pollution that's already there simply has nowhere to go. And that's why controlling pollution throughout the year matters. Delhi also has year-round pollution control policies. These include rules to control construction dust, clean roads, reduce vehicle and industrial emissions, and expand electric public transport. But questions have been raised about the efficacy of some of these policies. Now air does not stop at state borders. So all the pollution in Delhi doesn't actually come from Delhi. About 24 km on this side is Delhi's border with Haryana and about 20 km on the other side is the state of Uttar Pradesh. Pollution from factories, vehicles, agricultural fires and other activities can travel across northern India depending on wind and weather. Burning crop residue in neighbouring states like Haryana and Punjab has been cited as a contributor to Delhi's winter pollution. A scientific study published in April 2026 examined why this matters. It showed that pollution control measures over a larger region could have a much greater impact on Delhi's pollution than measures restricted to its borders. This means cleaning Delhi's air requires multiple state governments to work together, sometimes across political lines. This becomes a significant administrative challenge. Then there's Delhi's garbage problem. Every day the city generates thousands of tons of waste but it does not have the capacity to process all of it. And some of that waste ends up in landfills like this which over the years have become mountains of untreated garbage. Now Delhi has three such landfills, this one is Okhla and then there are two others in Bhalaswa and Ghazipur. Now when the garbage here catches fire, it releases harmful pollutants and smoke into the air. The government is trying to clear these landfills but more garbage arrives even as the old is yet to be cleared out. According to Delhi's economic survey, only around 63% of the city's daily waste was being processed in 2025 and 2026. In October 2026, the Delhi government announced new waste processing facilities to tackle this problem and clear out all the landfills by the end of 2027. But unless Delhi can process all the waste it generates every day and safely clear what has already accumulated, its garbage problem is going to remain an obstacle for cleaner air. Does all of this mean that Delhi has made no progress in tackling air pollution? No. According to government data, the city's annual average PM2.5 pollution fell from 114 micrograms per cubic metre in 2018 to 97 in 2025. That's an improvement of roughly 15%. There's proof of some other policies working as well. For example, the CAQM reported in late 2025 that 96% of industries across Delhi and the National Capital Region had shifted to approved fuels after policy intervention. But in spite of this, even today, Delhi's annual average particulate matter pollution is higher than the standard set for India. It is also 20 times higher than the safe levels recommended by the World Health Organisation. There's of course a lot to be done and shortfalls have been reported in Delhi government's air pollution action plan. The CAQM reported in January 2026 that road sweeping in Delhi fell around 70% short of the required levels. It also found an 87% shortfall in inspections of large construction sites. A report by the Comptroller and Auditor General of India, or the CAG, tabled in the Delhi Assembly in April 2025, found that more than 1 lakh or 100,000 vehicles had been issued pollution certificates despite exceeding permissible limits. There's more. A response to a Right to Information inquiry in September 2026 revealed that nearly 60% of the pollution compensation fund of the Delhi government remained unspent. This is in spite of the city's worsening air pollution. So is cleaning Delhi's air impossible? Well, not really. Other cities around the world which once had pollution levels as high as Delhi's have shown that improvement is possible. Take Beijing. In 2013, its annual fine particle pollution was nearly as high as Delhi's is today. By 2025, it had fallen by almost 70%, following years of action against pollution from coal, vehicles and industry. There's also Mexico City, once considered one of the world's most polluted capitals. Over several decades, it introduced stricter vehicle emission rules, cleaner fuels, industrial controls and expanded public transport. Now, particulate pollution levels here are 60% lower compared to 1990. Fuel, which converted thousands of diesel buses to cleaner fuels, imposed controls on older diesel vehicles and expanded electric transport, saw its fine particle pollution fall by 40% between 2006 and 2025. So yes, cleaning Delhi's air is difficult, but it is not impossible. Experts say the key lies in sustained coordinated efforts against pollution sources, not just in winter, but throughout the year. If you enjoyed watching this explainer, then like the video and don't forget to subscribe to BBC News India's YouTube channel. And if you have any question that you'd like us to answer in a future explainer, then drop them down in the comments below. Thanks for watching.