Pollution is killing Indians! Long-term exposure to PM.25 led to nearly 1.5 million deaths, says Lancet study

Delhi was third in the list with an average PM2.5 of 77.4, while the national capital New Delhi came in at 6th in the list. (Image: PTI)

A sustained exposure to hazardous levels of PM 2.5 has been linked with over 1.5 million deaths in India, a latest Lancet report says. According to the study published in the Lancet Planetary Health on Wednesday, the entire Indian population of 1.4 billion people lived in areas with PM2.5 concentrations above that recommended by the WHO guidelines, and 1·1 billion of 1·4 billion (81·9% of the total population) lived in areas above the Indian NAAQS (National Ambient Air Quality Standards).

The study also finds out that an estimate of 1·5 million deaths in India occurred annually due to the long-term exposure to PM2·5 in excess of the 5 μg/m3 that is recommended by the WHO guidelines.

The current PM2.5 level based on the average air quality level across India is 69 µg/m³, which is 4.6x above the recommended WHO guideline of 15 µg/m³. The unit μg/m3 is micrograms (one-millionth of a gram) per cubic meter air.

Long-term exposure to PM2.5, or fine particulate matter, can lead to reduced lung function, development of cardiovascular and respiratory diseases, and increased rate of disease progression, and can also lead to all-cause morality.

According to the World Air Quality Report 2023, the top 5 most polluted country and region ranking based on annual average PM2.5 concentration (μg/m³) are — Bangladesh, Pakistan, India, Tajikistan and Burkina Faso.

The study further mentioned that the national population-weighted median PM2·5 per district was 38·9 μg/m3 (5–95th percentile 19·7–71·8 μg/m3) for the whole study period (2009 to 2019).

With the exposure of the fine particulate matter being high over time, the minimum PM2·5 concentration of 11·2 μg/m3 was observed in Lower Subansiri district, Arunachal Pradesh, in 2019. Whereas, the maximum of 119·0 μg/m3 was observed in Ghaziabad, Uttar Pradesh, and Delhi in 2016.

In India, people living in urban and several rural areas are exposed to high PM2.5 concentrations throughout the year. As per the study, population-weighted mean PM2.5 exposure (2000 to 2019) across India was reported at 57·3 µg/m³, with higher concentrations observed from 2010 to 2019.