Delhi Air Pollution - 5 Solutions in the Hands of Citizens

It is late November in 2023. I am in a packed metro train in Delhi. And around me, all I can hear above the sound of the rails is people coughing and clearing their throats. Soon enough, I feel the familiar irritation and soreness in my throat. Welcoming me to one of the world’s most polluted cities.

Every year, just as the weather cools in and around Delhi, a dark pall of smog descends on the area. On some days the Air Quality Index (AQI) exceeds the upper limits of the scale, considered to be high enough to declare a health emergency. The most concerning pollutant is Fine Particulate Matter (PM) 2.5, tiny particles of a diameter less than 2.5 micrometres. On November 6th, 2023, the average PM 2.5 concentration was 261 micrograms per cubic meter, over 10 times the safe limits as per 2021 guidelines by the World Health Organization (WHO).

Needless to say, sustained exposure to these levels of pollution causes all kinds of health problems. Some shocking statistics to consider: breathing Delhi air in winter is like smoking 20 to 30 cigarettes a day, Delhiites lifespans are shortened by 12 years, incidence of asthma amongst children is estimated to be in the double digits, etc.

What Causes the Pollution?

It was not always like this. Growing up in Delhi during the 70s and 80s I don’t remember such badly polluted air. So, what changed? Unfortunately, air pollution in Delhi is a result of a perfect storm of factors, some new, some age-old, and not all of which are within the control of the local administration. There are a lot of scientific studies that have examined this issue in depth. And though the factors are well known, there is no consensus on the exact contribution of each.

One of the best analyses in recent times is this one by a team of researchers, if you want to dive into the details - What Is Polluting Delhi’s Air? A Review from 1990 to 2022. A really telling chart from this study shows the increase in pollution over the years.

For the lay person, here is a simple primer based on my understanding of the various research reports on this subject.

Geography

Let’s begin with geography. Delhi sits in an area called the Indo-Gangetic plain, protected by the Himalayas to the north, and irrigated by perennial rivers like the Ganga and Yamuna. While this makes it one of the world’s most fertile regions, it also results in two factors that contribute significantly to air pollution. Firstly, the winter wind is gentle, and blows from the north-west. Bringing fine alluvial dust that hangs in the air, but not enough moisture to bring rain. Secondly, an atmospheric inversion layer forms above the Indo-Gangetic plains in winter, which the prevailing winds are too weak to break-up. This weather phenomenon causes cold air close to the ground get trapped below a layer of warm air, trapping pollutants, and creating a 1 km layer of smog.

Crop residue burning

Now let’s look at manmade factors. The one that is talked about most is the burning of crop residues in the agricultural state of Punjab to the North-West of Delhi. This is a seasonal phenomenon driven by farm economics. After harvesting rice in October, farmers find it more cost efficient to burn the residual stalks than to cut it. Burning is quick, free, fertilizes the soil, and the smoke drifts away to the south. And farmers have been doing this for centuries.

But at the root of this are two intersecting government policies. The first is a national (federal) incentive that guarantees a minimum price for rice, combined with fertilizer and power subsidies, making it a commercially attractive crop despite the region not being suited to a water intensive plant. And rice is the most common crop that is burnt post-harvest.

The second factor is the implementation of the Punjab Preservation of Subsoil Water Act in 2009. This was a well-meaning law designed to reduce the dangerous depletion of ground water in a dry and arid state. It mandated delayed paddy sowing to coincide with the arrival of the monsoons and reduce the use of ground water to flood the fields. Unfortunately, it had an unintended consequence. It changed the traditional crop cycle, leading to a month's delay in stubble burning, coinciding with the change in wind patterns, contributing to the air pollution problems in Delhi.

Vehicular pollution

Vehicular pollution is the second major factor in Delhi, and a year-round one. According to the Print, Delhi city had over 12 million vehicles on the road in 2022, significantly more than any other metro city in India. Many of these are old and poorly maintained commercial vehicles that burn diesel fuel or use inefficient two stroke engines to power two wheelers and three wheelers. Despite strict pollution standards and recent legislation phasing out old vehicles, lax enforcement results in plumes of smoke, soot, nitrogen oxide, and sulphur dioxide being emitted from millions of vehicles every day.

Thermal Power Plants

According to a new study by the Centre for Science and Environment, Coal-based thermal power plants ignoring pollution control measures, responsible for aggravating air pollution in Delhi-NCR, says new CSE report (cseindia.org), 8% of Delhi's air pollution is contributed by coal fired thermal power plants in the region. Despite new guidelines by the environmental ministry, only 2 out of 12 thermal power plants have installed pollution control equipment.

Waste and Biomass burning

A less commonly talked about factor is the burning of biomass and plastic for cooking, warmth, and waste disposal. A significant percent of people in Delhi and surrounding areas are too poor to afford heating in their homes, or even have access to gas for cooking. As a result, they burn wood, leaves, and dried cow dung for cooking, and in winter, they also burn it for warmth. It is common in winter to see groups of people huddled around a fire fueled by fallen leaves, wastepaper and plastic.

Another big factor is poor waste management practices resulting in massive open garbage dumps that are continuously ablaze, emitting noxious fumes. Additionally, a lot of mixed waste is burnt in the open in local communities where waste collection is poorly managed.

Alluvial Dust

Finally, we come back to our old culprit – dust. While some dust is blown in from nearby deserts, there is a lot of fine dust generated locally by endless construction projects, churned up from roads by vehicles, and swept into the air from sidewalks by street sweepers. The unique alluvial soil of the region is so fine that it hangs in the air for days on end, contributing to particulate matter in the smog.

Hope is on the Horizon

There is no silver bullet solution for this problem. It will require deep, long term, and bold steps to be taken in coordination between state and central governments, industry, civil society, and even the courts. However, there are 5 areas where I see signs of hope, and opportunities for individuals and corporations to make an impact.

1. Switch to Millets

India has been cultivating millets like jowar, bajra, and ragi, for over 7,000 years, but in the 20th century it was replaced by rice and wheat thanks to the green revolution. However, millets are making a comeback through a renewed focus by the central government. For good reasons. They are ideally suited to dry and arid conditions, require less fertilizer and pesticide, are more nutritious, have lower glycaemic index, and are gluten free.

So, if you are a Delhiite, seek out millets, they will transform your life in more ways than you can imagine.

A shift to millet cultivation in Northern India will allow earlier cropping, reduce water usage, and improve farm income with the right government incentives. And most importantly, it will reduce the problem of crop burning in cold weather. The Delhi and Punjab governments need to accelerate the millet transition by creating markets for the grain, supporting innovations from seed to plate, and raising consumer awareness about the product.

2. Accelerate the EV Transition

There is a quiet revolution underway in India – the shift to electrification of the last mile delivery system. The proliferation of two wheel and three-wheel electric vehicles is going to transform the air quality in Indian cities, since they are amongst the biggest polluters. And the short distance, start-stop nature of hyperlocal delivery makes it ideal for electrification. Apart from this, there are startups that have launched electric bus fleets that will help reduce diesel fumes.

In 2020, the government introduced subsidies for the purchase of EVs, which has significantly improved the economics for prospective buyers. In the first half of 2023, the sales of EVs have increased by 20% whereas the sales of diesel vehicles have reduced by 24%. Citizens can accelerate this shift by favouring companies that use electric vehicles for their transportation and logistics.

3. Widen LPG Availability

What many people do not realize is that a surprising solution to climate change is a fossil fuel subsidy. Switching from solid biomass to liquified petroleum gas (LPG) is hugely beneficial to the health of people and the environment. Solid biomass emits smoke, toxic gases, excessive CO2, and consumes a lot more time to gather. Since 2016, India has dramatically improved access to LPG for poor households through well targeted subsidies, and now in Delhi there is near universal usage. But a lot more needs to be done in surrounding states, especially UP, to reduce pollution from cooking in the region. The government has encouraged wealthy citizens to give up their LPG subsidy so that poor households can benefit more. Hopefully everyone in India that is reading this article has taken this simple step to protect their health and that of their children.

4. Travel by Delhi Metro

I have started to use the Delhi Metro to get around the city, and found it to be fast, convenient, and safe. And outside of rush hour, it is much more comfortable than battling traffic, noise, and pollution on the roads. The Metro continues to be expanded and built to international standards of safety and environmental considerations, producing minimal construction debris and dust. It is a gold standard that needs to be applied to all future public works and private construction projects in India. Estimates are that the Metro alone has replaced millions of private vehicle trips in the city and earned significant income through the sale of 3.3 million carbon credits.

Unfortunately, many of the wealthy and middle-class residents still hesitate to use it, though a big solution to the pollution problem rests in a small metro card in their hands.

5. Techno-Commercial Solutions

The startup space in India has seen the advancement of techno-commercial solutions that can help tackle air pollution in Delhi. Devic Earth is a Bangalore-based company that has developed PureSkies which uses Pulsed Radio Wave Technology that can improve air quality over large areas at a low cost per unit area. A Pune-based startup called Omni Ion, mentored by IIT Delhi, recently successfully tested its device which can reduce particulate pollution by up to 86% in a matter of two hours.

Pollution control devices like electrostatic precipitators have been around for a while, but thermal power plant operators in the region either lack them, or do not operate them well. Since they are mostly government owned, there needs to be political will to force them to implement solutions. However, the cost will need to be passed on to consumers, which may not go down well with the masses.

Every year during Diwali (Festival of Lights), millions of households burst firecrackers, which coincides with the worst of the inversion layer to cause a huge spike in pollution. Despite bans and social pressure, there is no let-up in this practice. However, there is hope in the form of smokeless firecrackers. The Indian Institutes of Science Education and Research (IISER), Mohali is developing a prototype in which there is light and sound, but no smoke.

Some Final Thoughts

China had a severe problem with air pollution in Shanghai and Beijing but solved it within a few years during the run-up to the Olympics. I am optimistic that the problem in India will be solved too, but in a raucous, multi-party democracy, the path will be longer, and more winding. Yet, I know it will take into account needs of all the stakeholders.

And while the present is dark and gloomy, I see clearer skies on the horizon.