Delhi’s geography is truly cursed: Siddharth Singh, author of 'The Great Smog of India'

Early this month, as it now happens every November, New Delhi and the NCR recorded acute levels of air pollution. But the debate on the issue is muddled by politics. In an email interview with Sruthijith KK, energy researcher and the author of The Great Smog of India, Siddharth Singh, tackles key questions. Here're are the edited excerpts:
What are the factors that cause extreme air pollution in NCR? Does anyone really know which factor is responsible to what extent?
Even though we do not have real-time source-based data for air pollution for all affected cities and towns, we know enough to act decisively. Various studies have shown that the key sources that contribute to air pollution in NCR are motorised road transport, dust on roads and construction sites, brick kilns, polluting industries, coal fired power plants and biomass burning. While the precise contribution of each sector may vary depending on the methodology of each study, we know that these are the main sources.

How many months in a year does NCR typically have acceptable air quality? When does the deterioration begin and end?
Forget months or even weeks, we had only a handful days of good air quality in the past few years. On days when you see clear blue skies, check the AQI reading. It will often indicate unacceptable air quality. This is because the finest particulate matter is invisible to the naked eye. PM2.5 is at least one-twentieth of the width of a human hair.

Is stubble burning a big cause of air pollution in NCR and north India?
While emissions from transport, industry, power generation and dust are the mainstay of pollutants in India, stubble burning is a huge contributory factor October onwards in NCR and north India in general. It takes an already bad situation and spirals it out of control.

Has the practice of stubble burning in Punjab and Haryana become more widespread in recent years?
Yes it has become more acute now. This is due to a variety of reasons, including types of seeds used and government policies that encourage late harvesting to save groundwater. Farmers have too little time to clear the fields for the next crop. There is also a mistaken belief that burning the stubble will take the nutrients back to the soil. This is not true.



Does winter play a role in accentuating air pollution? Is this because of wind direction, temperature or low humidity?
In my book The Great Smog of India, I have referred to this problem as the ‘meteorological misfortune’. Delhi’s weather and geography is truly cursed. Just as the stubble burning season begins in October, the wind direction changes to bring pollutants from Punjab and Haryana to Delhi. Wind speeds also slow down, meaning the pollutants then can’t be easily evacuated. The Himalayas to the north are — excuse the pun — a Himalayan barrier.

What about vehicular pollution is? Is the odd-even policy effective from a pollution mitigation point of view?
When a city like Paris attempts odd-even, it works because on their worst air quality days, most pollutants come from the vehicles. In Delhi’s case, that is just not true as smoke from stubble burning is the major cause. So even if odd-even in Delhi ends up reducing some emissions, we would never know because it is too little to make a difference. Politicians wrongly attribute cleaner air, which happens due to faster winds, to odd-even. The correct way to clean up the transport sector is to ensure safer, convenient and comfortable public transport, and the electrification of all vehicles. This will have to go hand-in-hand with ensuring this electricity is increasingly generated from renewable sources.

Why do paddy farmers in other states not burn stubble?
Stubble burning is more common around India than we think. However, it is certainly more intense and widespread in Punjab and Haryana. This is a result of the ‘rice-wheat cropping system’, combined with the use of certain seeds that harvest at that time of the year and government policies. These unique circumstances make these states the worst affected.

If we exclude the effect of crop burning, has the round-the-year air quality in NCR improved?
There is no evidence of that just yet. We have more cars and trucks than before, our industries are still firing, we have not reduced emissions from brick kilns, and there is no comprehensive dust management plan as such.

Is NCR the most polluted place in the country?
Delhi may be the most polluted of the big cities, but several smaller towns have equally bad or worse air quality. Air pollution is not merely an urban issue. More people die in rural India due to pollution-related illnesses. We just don’t have enough sensors to continuously measure it.

What policy interventions do you reckon could make a difference to air pollution in NCR and north India?
The main issue with air pollution is that it is nobody’s baby. Yes, the environment ministry and pollution control boards do make a difference. But to curb air pollution, one has to transform the sources. India needs an umbrella policy for air pollution that is at the core of our industrial, transport, energy, urban and rural planning. This needs to be complemented by an inter-state and inter-ministerial body that can keep a track of compliance.

Is the situation beyond repair, or is it possible to ensure clean air in NCR around the year in a couple of years?
While it may take several years to comprehensively deal with the issue across all sectors of the economy, in the short run, there should be a mission-mode campaign to end stubble burning, to manage dust and to remove the most polluting vehicles and factories. This will at the very least shave off the peaks. Stubble burning can be addressed by an intelligent minimum support price mechanism and agricultural policies that encourage crop diversification, awareness campaigns, and by putting a price on stubble.

Are mitigation measures such as air purifiers and masks effective? Or as a prominent doctor recently said, these are not useful?
They absolutely are effective. Air purifiers and masks are not a solution to the problem, but they are a necessary precaution. The sceptical minds can test this for themselves. Find or borrow a PM2.5 sensor and take measurements before and after turning on an air purifier. It is for everyone to see. Don’t forget that particulate matter has proven links with brain ischemia, cardio vascular diseases, strokes, congestive heart disease, thrombosis, lung inflammation, asthma, and more. We must limit exposure to the extent possible.