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Why Isn’t Science Part of the Fight Against Air Pollution in India?

Why Isn’t Science Part of the Fight Against Air Pollution in India?

air pollution, cloud seeding, Delhi, New Delhi, Air Quality Index, air quality life index, respiratory health, DALY, disability adjusted life years, Swachh Bharat Abhiyan, Prime Minister Narendra Modi,

A possible increase in the coronavirus case load in the coming days is also likely to stress hospitals and the availability of hospital beds. Thus, we must manage all our diseases responsibly to ensure we are not letting people fall sick out of carelessness, incompetence or pseudoscience. Since the virus is more likely to affect those with beleaguered immune systems, a population already suffering due to air pollution is likely to be even more vulnerable.

An analysis of Google search trends for phrases like “Delhi air pollution” and “India air pollution” suggests public interest in the topic remains strong throughout the year, even after peaking around Diwali at the start of winter, and the stubble-burning season. It’s an issue that citizens are mindful of, demand action over and is already a seasonally political issue, and is likely with time to become perennial.

However, even when politicians are eager to respond to the call for better air from citizens, supported by a substantial body of scientific knowledge, why does the gap between objective, science-based air pollution research and air pollution policy persist?

There are three possible reasons.

Denying the health impact

It’s hard to deny the adverse impact of air pollution on public health. The scientific literature is full of studies documenting the physical, mental and emotional consequences of air pollution. The very young and the old are particularly vulnerable, and consequences enumerated in the studies include hair loss, lung ageing and disease risk, reduced prenatal heart rates and loss of skeletal muscle mass. But in spite of this overwhelming evidence, India’s official policy stance has been that no Indian studies have quantified the health effects of air pollution, and that the government won’t rely on ‘foreign’ results.

As it happens, air pollution doesn’t discriminate by nationality.

Even should we pander to the government’s prejudice, there are in fact Indian studies that fit the bill.

In 2016, scientists at the Indian Institute of Tropical Meteorology, Pune, estimated that exposure to higher levels of PM2.5 particles and ozone had caused 582,000 premature deaths and a loss of 3.4 years of life. In December 2018, a study led by researchers at the Indian Council of Medical Research and funded partly by the government estimated 627,000 and 480,000 premature deaths due to exposure to outdoor and indoor PM2.5 pollution, respectively, in 2017.

Similarly, in March 2020, a study from IIT Kanpur estimated 114,700 deaths in 29 cities due to outdoor PM2.5 pollution. While previous studies used national or state-level mortality data, this city-specific study used the registered number of deaths together with information on share of cause-specific deaths reported on death certificates, and measured ambient PM2.5 concentration to estimate a baseline mortality.

So it’s high time the government acknowledges that air pollution is the primary cause of a recent increase in the number of respiratory and cardiovascular diseases in India. Having a sense of the magnitude of the issue will allow policies to reduce pollution to have a stronger mandate.

Misunderstanding realities

Even when the issue of air pollution finds its way to parliament, lawmakers drop the ball. They make the right political noises but don’t follow through. Instead, they pass off old resolutions as new answers. These include addition of PM2.5 to the list of criteria pollutants in 2009, introduction of the air quality index (AQI) in 2014, ratification of emission standards for power plants in 2015, a National Clean Air Programme (NCAP) in 2018, and the upcoming introduction of Bharat 6 fuel for the transportation sector from April 2020. These announcements are great for public relations but half of them won’t improve the air quality. Here’s a breakdown:

PM2.5 as a criterion pollutant

According to the 2011 Census, there are about 8,000 notified urban centres. As of February 2020, the Central Pollution Control Board (CPCB) operated 200 continuous monitoring stations in 45 cities. PM2.5 is the most important criterion pollutant in India and 11 years after it was qualified as one, we barely hardly know how much of it is really there in the air. Most of what we do know is due to modelling efforts, and they’re often ridiculed for being off the mark.


Under the AQI system, air quality reporting happens through colour codes – the number of days marked green (good air) or yellow (moderate air) – and the percentage of days that moved from ‘hazardous’ to ‘very poor’ and from ‘very poor’ to ‘poor’. Note that these bands represent pollution levels at least four-times worse than the WHO guidelines.

However, in an effort to simplify the communication of pollution levels, our lawmakers have cut off access to the actual data from 700+ manual monitoring stations. And today, lawmakers are only interested in the subjective AQI score, which doesn’t lend itself to much scientific analysis.

Power plants emission regulations

The environment ministry ratified new emissions regulations for power plants in December 2015. The original deadline to implement them was December 2017 but was then pushed to December 2019 and then changed to staggered implementation by December 2022.

Planning to commissioning a flue gas desulphurisation system requires at least 18 months. However, CPCB notifications suggest there has been little progress at most power plants. So while these standards appear stellar on paper, we still lag on planning and enforcement.


The NCAP aims to enhance overall urban and rural ambient air-monitoring capacity and design action plans to cut PM2.5 levels by 20-30% in 122 cities by 2024. However, these targets aren’t legally binding and none of the sectoral departments listed in the programme are accountable for actual implementation.

In the Union budget for 2020, the government announced Rs 4,400 crore to help fight air pollution in the 50 or so cities with more than a million people each, which translates to roughly Rs 90 crore per city. These funds are to support monitoring and mitigation efforts. To compare, in 2019, the Bihar State Pollution Control Board estimated that their action plan for Patna city would need at least Rs 4,000 crore to reduce PM2.5 pollution.

Bharat 6 fuel

The government made this fuel available only in Delhi from April 2018; it will be available across the country from April 2020. Irrespective of the engine type, it is expected to reduce PM2.5, SO2, NOx, CO and VOCs emissions. It’s expected to be at its most performant when used in a Bharat 6 engine, also due to be available for sale from April 2020. Given the urban vehicular turnover, the true benefits of this combination will likely be realised only from 2022. Vehicle exhaust is one of the major sources of air pollution in India’s cities and a jump from Bharat standards 4 to 6 will be a key improvement.

However, lawmakers should understand that more monitoring, more AQI reporting, more standards on paper and even conducting more studies are not going to reduce pollution. We need hard decisions but also implementation and enforcement in transport, industries, cooking and heating, waste management, road management, construction and demolition, and urban planning.

The decision-making process can be strengthened with studies to map the top sources of pollution. However, studies of the unknown shouldn’t stall the implementation of known control measures.

Miseducation of science

The idea of controlling air pollution is unambiguous: it means reducing emissions at the sources, before they enter the atmosphere.

Once in the air, the emitted substances disperse and are chemically transformed to other gases (like ozone) or aerosols (like sulphates and nitrates). The only ways to get rid of what is already in the air is for winds to blow it away or to bring them down by wet deposition (under rains). Neither option is in our hands, so the best option is to reduce emissions at the source.

Some – including, frustratingly, the Supreme Court – have pushed gimmicks like smog towers, which are giant vacuum cleaners that trap dust but do very little to clean the air. A local politician unveiled one smog tower at the Lajpat Nagar market in Delhi in January 2020 to the accompaniment of fawning covering in the mainstream press. However, operation reports indicate the tower either operates for only a few hours every day or not at all. When it does run, it has zero impact on the ambient air.

The Council on Energy Environment and Water has estimated that even if the Lajpat Nagar tower had an appreciable difference on the air quality, Delhi would need at least 2.5 million similar towers for a total cost of Rs 1.75 lakh crore.


Identifying the important contributing sources and implementing strategic solutions will accountably improve air quality. For a fraction of the cost of installing 2.5 million smog towers, Delhi can increase its urban bus fleet to at least 15,000, set up the necessary infrastructure to promote walking and cycling, maintain roads to reduce dust resuspension, enhance waste collection and landfill management facilities, and help neighbourhood power plants to adopt new emission regulations.

Consistent long-term planning is not easy: it requires investment in basic infrastructure and stronger local governance systems, along with paying heed to basic science and evidence-based research.

Sarath Guttikunda is the director of Urban Emissions (India), an independent research group on air pollution, issuing three-day air quality forecasts for all Indian districts.

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