Fundamental policy changes aimed at fixing India’s seemingly intractable air pollution health crisis were suggested at the India Clean Air Summit (ICAS) held in Bengaluru recently. 

Among the dozens of presentations by air quality scientists and officials, five key elements emerged for policy action that can speed up the reduction of air pollutants. These involve: adopting an airshed approach rather than the prevalent city-centric approach; changing the core focus of the National Clean Air Programme (NCAP); tackling indoor household pollution; sharply reducing combustion and black carbon emissions; and plugging data gaps with low-cost sensors and modelling. 

Hosted by the Center for Study of Science, Technology and Policy (CSTEP), the sixth meeting of what has become a staple of the global air quality ecosystem, was attended by over 300 Indian and international scientists, government officials, policymakers, health officials, political leaders and civil society. 

India’s ambient air pollution, both outdoors and indoors, has been linked to over two million premature deaths annually. This includes about 170,000 children. Pollution levels have stayed in the same ballpark for the last five years, which is more than 10 times the WHO’s guidelines (see IQAir table below); in places like Delhi it is about 20 times higher. 

Change focus from cities to airsheds

India’s main air pollution control programme, NCAP, is currently city-focused. It incentivises 131 cities to reduce pollution, and in return, these are allocated federal funds. The problem with this approach is that much of cities’ pollution comes from outside their jurisdiction, so urban local bodies (ULBs) are helpless. 

In a new study, CSTEP documented the emission inventory, or local sources of pollution, in 76 Indian cities, perhaps one of the largest such studies anywhere. 

Take, for example, Ghaziabad which borders Delhi in the east and has been identified as one of the most polluted cities in the world. The PM 2.5 pollution measures over 28,000 tonnes per year. But 95% is from the greater city area. PM 2.5 is a microscopic particulate matter pollutant which can settle deep inside the human body and is linked to multiple health disorders such as chronic lung disease, strokes, heart attacks, cancers as well as depression and hypertension. 

It is similar to Davangere, a small town in Karnataka. 

Meanwhile, for an industrial town like Kalinga Nagar in Odisha, which has large factories inside and outside city jurisdictions, the share of PM 2.5 is almost equally divided. 

The report points out that most of the cities will not be able to achieve NCAP’s target of reducing pollution by 40%. 

“Our preliminary air quality modelling results also suggest that emissions from outside the city – what we call the airshed – can also be significant contributors to urban air pollution,” said Dr R Subramanian, who heads the Air Quality Sector at CSTEP.

“We need a broader, comprehensive approach that reduces emissions from the city and the airshed at large – actions that likely require national or state-level interventions and investments in systemic change to reduce fossil fuel and biofuel use in favour of clean, renewable energy. This will move us firmly towards clean air for all – for people in cities, periurban areas, and in villages across the country.”

Ashish Tiwari, the top environment officer of Uttar Pradesh, India’s most populous state and one of the most polluted, called for NCAP to drop its city-centric approach and target airsheds. 

“We have strongly recommended that NCAP must adopt this airshed approach. And I am happy to tell you that MoEFCC (Ministry of Environment, Forests and Climate Change) has started mulling over it, and very soon, I think the airshed coordination committee of eight IGP states will see the light of day,” said Tiwari.

Focus on PM 2.5

Announced in 2019, NCAP’s target is to reduce up to 40% the concentration of PM 10 by 2025-26. While PM 10 is a health risk, the finer PM 2.5 pollution can be more toxic and easily defeat the human body’s defence mechanisms. At times, the larger PM 10 can be controlled using equipment like vacuuming and mist-spraying trucks used to contain road dust. 

There’s no silver bullet to cut air pollution, but ensuring clean cooking fuel was one step backed by many scientists and officials in India and other parts of the Global South. Currently, the use of heavily polluting fuels, like wood, coal and biomass, is widely used, which emits a “cocktail” of toxic elements, as health expert Professor Kalpana Balakrishnan, a senior WHO and ICMR official, described it. 

These include PM 2.5, carbon dioxide, carbon monoxide, benzene, sulphur oxides and nitrogen oxides, among others. All this is inhaled near the polluting stove. 

Balakrishnan pointed out that different studies have put the share of household air pollution anywhere between 20 to 50%, which is a significant part of India’s ambient air pollution crisis. 

In 2016, the government launched a widely hailed programme, the Pradhan Mantri Ujjwala Yojana (PMUY), to provide free subscriptions to a gas cylinder; some refills are free but most are paid. Studies have documented a decline in PM 2.5 exposure thanks to the Ujjwala scheme. 

Several experts at ICAS called for more funding to reduce costs for the beneficiaries. Women, invariably those cooking at home, prefer using a cooking gas cylinder. But the cost of refilling – about Rs 800 or $10 per cylinder – is a challenge for most low-income beneficiaries.

However, there is a divergence between the government and health experts. In the current financial year, the government’s budget support for cooking gas subsidies has declined by 2.5%. Various studies have report

Uttar Pradesh, which has 18 million Ujjwala beneficiaries, the highest, is banking on other ‘clean’ cooking solutions such as bio-digesters and induction cooktops, Tiwari said at ICAS. He flagged the low-income status of the beneficiaries, saying, “PMUY is actually linked with the income level of the households. So that will take time. We have to think about the intermediate solutions for clean cooking. So increased bio-gas uses can actually break down PM 2.5 by 97%, black carbon by 92%, and carbon dioxide-equivalent by 70%.”

However, Balakrishnan, pointed out that there are several studies where primarily LPG (liquified petroleum gas) was used, comparing it to the use of biomass. In a “majority, or virtually all of the outcomes, the central estimate is favouring LPG. So there is very convincing evidence that the use of LPG, A, reduces exposures, B, is associated with improved health outcomes…”

Reduce combustion, track super-pollutants

Scientists like Dr Sarath Guttikunda, Founder and Director of Urban Emission, pointed out that another significant way to start reducing air pollution was to address the increasing combustion of fossil fuels. He presented data to show a rising trend in the production and consumption of coal, oil and gas. 

Monthly data shows rising production and consumption of fossil fuels. 

Anumita Roychowdhury, executive director at the Centre for Science and Environment and one of the panellists at ICAS 2024, warned that some pollutants, particularly black carbon, were not being monitored enough.

“Science is telling us that there are some subsets of particulate matter such as black carbon that have much more warming potential than CO2. Moreover, when they settle on snow and glaciers, they melt and result in a water security threat. They also affect cloud formation and interfere with rainfall patterns,” she said. 

Black carbon (BC) is strongly correlated with increased blood pressure levels, a high-risk factor for cardiovascular disease and strokes. It affects pregnant women and has been linked to low birth weight. Because it has a short lifespan of about a week or two in the atmosphere and yet so many devastating effects, it is known as a super-pollutant. Common sources of BC include brick kilns, burning waste, incomplete combustion of fuels, forest fires, and burning of crop stubble. There are policies and programmes in place to reduce these, but they need to be accelerated. 

Plugging data gaps 

Finally, air quality monitoring has drastically improved with the government installing regulatory-grade monitors, from a handful a decade ago to about 550 now. But these are mainly in cities. A solution that has emerged over the last few years is low-cost sensors. At a fraction of the cost of the regulatory ones, these are reliable enough to provide actionable data. Hundreds of these are already in use nationwide as part of various programmes. 

If there has to be one backbone of the entire air quality management system, several participating scientists and officials cited the importance of modelling.

Guttikunda explains: “While monitoring data continues to be the cornerstone of regulations and management, air quality modelling needs to be the foundation of most of the discussions because this exercise provides us with information on how much, where is, when is, and what is contributing to the observed pollution levels. Going forward, in India, we need more emphasis on building this capacity.”

However, he cautions that since ambient monitoring is limited to specific locations and mostly to the cities, this data may not always reveal the full picture. “We need to keep a closer look at fossil fuel consumption trends in India, which determine the emission loads and pollution levels that we experience.”

Science vs pseudo-science

The clean air conference gave space to some frank talk about a crisis that frequently makes headlines in India. Dr Sachin Ghude, a government scientist at the Indian Institute of Tropical Meteorology, has helped to design the modelling system for Delhi based on which authorities may shut down schools and industrial units and restrict traffic among the more stringent measures to cut pollution in the short-term. 

Ghude took on the more controversial measures such as smog guns, water sprinkling, and cloud seeding often adopted or considered in Delhi and some other cities. He was clear that these are not effective in reducing pollution. Ironically, Delhi’s local state government was almost simultaneously pursuing cloud seeding.

ICAS was supported by Bloomberg Philanthropies, Open Philanthropy and Clean Air Fund, and partnered with Clean Air Monitoring and Solutions Network (CAMS-Net). 

Disclosure: Chetan was a communications consultant at ICAS.