More than 91 per cent of over 180 studies on the health effects of air pollution in India have reported at least one adverse health link, according to a new analysis.
The studies, published between 1975 and 2025, found that the impact of air pollution goes beyond respiratory illnesses. They also linked exposure to air pollution with cardiovascular diseases, diabetes, pregnancy complications, impaired child growth, tumours, blood disorders and mental and neurocognitive disorders.
The analysis was released on Friday by the Centre for Research on Energy and Clean Air (CREA), an independent research organisation that studies the trends, causes and health impacts of air pollution, along with possible solutions.
Rural areas also affected
Of the 180 studies examined, only 40 looked at the impact of air pollution on rural populations. As many as 38 of these reported at least one adverse health association.
The findings indicate that the health effects of air pollution are not limited to urban areas.
Most of the studies were conducted in Delhi, with 26 examining the link between air pollution and health. Punjab accounted for 13 studies, followed by Maharashtra and Uttar Pradesh with 11 each. West Bengal had 10 studies, Tamil Nadu nine, Karnataka eight and Telangana seven, the report said.
CREA analyst Manoj Kumar said the findings underline the need to move beyond a city-focused approach to tackling air pollution.
“The findings highlight the need to move beyond a city-centric approach and explicitly include rural areas through a regional, airshed-based approach in the next phase of National Clean Air Programme (NCAP 2.0),” he said.
Studies examine different pollutants
The studies examined different types of air pollutants. Of these, 45 looked at both particulate matter and gaseous pollutants. PM2.5 was examined in 32 studies, while four focused only on PM10. Another 16 studies looked at both PM10 and PM2.5.
Studies examining gaseous pollutants reported statistically significant adverse health links, including increased mortality, hospital and emergency visits for acute respiratory problems, asthma-related hospital admissions and impaired lung function.
The report also pointed out that gaseous pollutants such as sulphur oxides (SOx) and nitrogen oxides (NOx) contribute to the formation of secondary PM2.5. They undergo chemical reactions in the atmosphere to form sulphate and nitrate particles.
Kumar said efforts to reduce air pollution must address multiple pollutants, including gases that contribute to secondary PM2.5 and ground-level ozone formation.
“Air pollution mitigation must adopt a multipollutant approach, addressing gaseous precursors that contribute to secondary PM2.5 and ground-level ozone formation. This requires emission reductions at major sources, including industries, power plants, residential cooking, and other combustion activities,” he said.
