No conclusive data linking air pollution to deaths? Union environment minister’s statement shockingly uninformed

In response to a question by Congress president Mallikarjun Kharge, Union minister of environment, forest and climate change Kirti Vardhan Singh recently claimed in Rajya Sabha that there was no conclusive data to establish that air pollution caused disease or death.

The question posed by Kharge to the Union minister was as follows:

“Will the minister of environment, forest and climate change be pleased to state:

a) whether a new study in the Lancet magazine has claimed that air pollution itself accounted for 17.8 per cent of total deaths in India in 2019;

(b) if so, the reasons for the huge rise in deaths due to air pollution over the last few years;

(c) if not, Government’s estimate on number of deaths due to air pollution in the country

(d) steps being planned by the Government to curtail the menace of air pollution across the country; and

(e) whether there are any plans to regulate the use of highly polluting substances across the country by a central legislation?”

In response, Singh stated: “There is no conclusive data available to establish a direct correlation of death/disease exclusively due to air pollution(sic). Air pollution is one of the many factors affecting respiratory ailments and associated diseases. Health is impacted by a number of factors, which include food habits, occupational habits, socio-economic status, medical history, immunity, heredity, etc., of the individuals apart from the environment”.

The statement was not only summarily wrong, coming from the environment minister, it was shockingly uninformed.

Outdoor Air Pollution Caused 4.2 million Premature Deaths in 2019: WHO  

According to the World Health Organization (WHO), “the combined effects of ambient air pollution and household air pollution are associated with 6.7 million premature deaths annually.” In 2019, it was estimated that ambient (outdoor) air pollution in both urban and rural areas caused 4.2 million premature deaths worldwide.

These deaths are caused by exposure to fine particulate matter, which causes cardiovascular and respiratory disease and cancer. It is also believed to be one of the greatest environmental risks to child health, WHO states.

Breaking up the data on deaths caused by air pollution in 2019, WHO states that in 2019, “some 68% of outdoor air pollution related premature deaths were due to ischaemic heart disease and stroke, 14% were due to chronic obstructive pulmonary disease, 14% were due to acute lower respiratory infections, and 4% of deaths were due to lung cancers.”

The global health body also notes that the low and middle-income countries bear a disproportionate share of this burden, with 89% of the 4.2 million premature deaths occurring in these regions. The heaviest impact is seen in the WHO South-East Asia and Western Pacific regions, highlighting air pollution as a major driver of cardiovascular disease and mortality.”

The Lancet Study Cited by Kharge

The study by The Lancet Planetary Health published in December 2024 which was cited by Kharge in his question to Singh stated that long-term exposure to air pollution increased deaths by 1.5 million (15 Lakhs) per year in India.

The pollutants which heavily contribute to air pollution are: Particulate matter (PM), Carbon monoxide (CO), Ozone (O3), Nitrogen dioxide (NO2) and Sulfur dioxide (SO2).

Lancet researchers analysed district-level mortality data in India from 2009 to 2019 from the civil registration system, and gathered annual PM2.5 concentrations. The study also considered other factors such as ‘mean and SD of quarterly temperatures, gross domestic product per capita, population aged 60 years or older, clean cooking fuel usage, literacy in women, and median age’, which might affect the outcome of the study.

The study found that average PM2.5 levels in India were 38.9 μg/m³, far above the WHO’s recommended annual average limit of 5 μg/m³. More than 80% of the population lived in areas where PM2.5 levels exceeded India’s yearly average limit of 40 μg/m³, meaning the air did not meet the Indian National Ambient Air Quality Standards. The analysis shows that every 10 μg/m³ rise in annual PM2.5 levels was associated with an 8.6% increase in overall mortality. Based on the Indian National Ambient Air Quality Standards, the study estimated that 3.8 million deaths between 2009 and 2019 were due to PM2.5 exposure. However, when measured against the WHO guideline, which is far stricter than the national standards, the estimated number of deaths due to PM2.5 exposure rose to 16.6 million.

What does the British Medical Journal Say?

The British Medical Journal, one of the world’s leading peer-reviewed medical journals, published a modelling study in 2023 that estimated that outdoor air pollution caused about 2.18 million deaths every year in India, second only to China.

The study found that pollution from fossil fuels — used in power generation, industry and transport — accounted for 61% of the 8.3 million global deaths linked to ambient air pollution in 2019. Most of these deaths were associated with conditions such as heart disease, stroke, chronic lung disease and diabetes. The researchers concluded that phasing out fossil fuels could prevent a large share of these deaths, particularly in South and East Asia, and stressed that the health benefits of cleaner energy should be a central consideration in climate and environmental policy.

All these findings highlight the scale of mortality linked to long-term air pollution exposure in India and point to the urgent need for stricter air quality regulations. They also show that the environment minister’s response is very very far from the truth.

Alt News reached out to Kolkata-based consultant pulmonologist Dr Saurabh Maji, who expressed shock at the minister’s observation.

“Air Quality Index points to several components in the air, such as PM5 and PM2.5, Nitrogen Dioxide, Sulphur Dioxide, etc. Each of these components has a detrimental effect on our body, especially particulate matter 2.5 and smaller. They enter our bloodstream as we inhale them. It is almost impossible to stop them from getting into our bodies. As they are so small in size, masks can’t stop them. And this is a huge contributor to strokes amongst the young population”, Maji said.

“PM5 is a bit bigger in size, and gets stuck to our lungs. This can lead to lung diseases and lung cancer. Additionally, we all know that exposure to air pollution is the biggest contributor to chronic obstructive pulmonary disease (COPD), especially for those who are continually working outdoors. There is a high risk of death from being continually exposed to air pollution. The environment minister is absolutely wrong in saying that there is no direct relation between air pollution and death,” he added.

Why India’s Official AQI Readings are Inherently Misleading

It is pertinent to note that India’s official Air Quality Index (AQI) caps pollution readings at 500, even though actual pollution levels in cities like Delhi often rise far higher, sometimes crossing 1,000 on private and international monitors. A BBC News report explains that this cap was introduced over a decade ago to signal a “severe” pollution emergency and to avoid public panic, based on the assumption that health impacts beyond this level would not significantly differ.

However, experts say this ceiling flattens data and masks how toxic the air really is. While global platforms report higher numbers, India relies on government-approved instruments that differ from sensor-based monitors used elsewhere. Scientists argue that the AQI framework is outdated and needs revision, as evidence now shows health risks continue to worsen with rising pollution levels, making the current cap misleading rather than protective.

The National Air Quality Index (NAQI) was launched in India in 2015 as a tool that would help simplify air quality data by classifying pollution levels into 6 categories — good, satisfactory, moderate, poor, very poor and severe. It assigns AQI values to key pollutants such as PM2.5, PM10, NO₂, carbon monoxide and ozone, with the daily overall AQI reflecting the worst pollutant in a given area. This helps people understand how polluted their surroundings are and which areas to avoid, and has improved public awareness. However, what remains unclear is how the local administration or governments should act when the AQI level is hazardous. Neither does the government outline any clear or aggressive action plan to guide people on the precautions to be taken.

A new study called A framework for city-specific air quality health index proposes adding the risk of death data as well to the AQI readings and calling it the Air Quality Health Index (AQHI). The study also argued that these indices need to be tailored to cities.

For this research, mortality and air pollution data from two cities were analysed – Delhi, a megacity, and Varanasi, a Tier-2 city. The study identified threshold levels of 65 µg/m³ for nitrogen dioxide (NO₂) and 52 µg/m³ for ozone (O₃). It assessed how different pollutants affected daily death rates in Varanasi and Delhi, as well as in combined estimates, by measuring the percentage increase in mortality for every 10-unit rise in pollutant levels.

Ozone levels at or below 52 µg/m³ were linked to the strongest increase in mortality in both cities. In Varanasi, deaths rose by 2.73% (95% CI: 1.63–3.83) for a 10-unit increase in ozone, compared to a 0.94% rise (95% CI: 0.38–1.51) in Delhi, pointing to clear differences in how pollution affects health across cities.