Our war against dirty air 

This article draws insights from the State of Global Air 2024 report, a collaboration between the Health Effects Institute and the Institute for Health Metrics and Evaluation – Global Burden of Disease project. The initiative provides open-access, reliable data on air pollution and its health impacts for the public, policymakers, and researchers worldwide.

Air pollution is a leading environmental risk factor for poor health worldwide. In India, exposure to air pollution accounted for nearly 18 percent of all deaths in 2021, more than 2.1 million deaths and 62.7 million healthy years of life lost. Among the top five risk factors for poor health in India, air pollution ranks first, followed by high blood pressure, dietary risks, tobacco use, and high fasting plasma glucose. Children are particularly vulnerable to exposure to air pollution.  In 2021, India saw the highest total number of deaths (169,400 deaths) in children under five due to air pollution.

Figure : Ranking of risk factors by total number of deaths in 2021 in South Asia

Trends in air pollution: A story of uneven progress

Around 62 percent of India’s population lives in areas where annual PM2.5 levels exceed the least stringent WHO Interim Target for healthy air (35 µg/m³), and 54 per cent live in areas where PM2.5 levels do not meet the national annual standard (40 µg/m³). In 2019, India experienced high levels of ambient PM2.5, with an annual average concentration of 59.8 µg/m³—significantly higher than both the global average (31.4 µg/m³) and the average in high-income countries. However, there is some good news — levels of PM2.5 have been stabilising in recent years. Furthermore, there has been a precipitous decline in exposure to household air pollution due to the use of clean fuels for cooking. Between 2010 and 2020, the percentage of the population dependent on solid fuels decreased from 73% to 60%.  Deaths from household air pollution (HAP) decreased from 1,261,000 in 2010 to 1,048,000 in 2021, a decrease of 213,000 (approximately).

Trends for other air pollutants paint a different picture. Exposure to ozone in India was among the highest in the world (67 ppb) in 2019—nearly five times higher than the global average —and is increasing. Heatwaves can intensify ozone pollution, posing risks to both human health and agricultural productivity. Levels of nitrogen dioxide (NO₂), a key indicator of traffic-related pollution, have increased by 6 percent compared to 2010 levels.

Health burden associated with exposure to air pollution

Exposure to air pollution has been associated with a wide range of health conditions. In India, a substantial proportion of deaths due to heart or lung diseases are due to air pollution (see image below). Deaths attributable to ambient PM2.5 have more than doubled in the last decade, from 448,100 in 2010 to 947,600 in 2021. Similarly, deaths attributable to ozone increased from 124,000 in 2010 to 237,700 in 2021. India experienced the highest number of deaths due to ozone exposure. Globally, this accounts for approximately 50 per cent of all ozone-related deaths. These increases are collectively driven by the rise in pollutant exposures and the ageing of the population. Among South Asian countries, India experiences the highest disease burden for asthma in children and adolescents due to NO₂ exposure.

For more information about the available evidence on the health effects of air pollution in India, explore the DoSAAH interactive literature database, featuring over 1,300 studies from across South Asia, by scanning here.

If you are curious to know more about the available evidence for the health effects of air pollution in India, check out the DoSAAH interactive literature database featuring more than 1300 studies from across South Asia by scanning here. 

Residential solid fuel use – a Major source of ambient PM2.5

The Major sources contributing to ambient PM2.5 pollution in India include the residential sector (25.7%), primarily from the use of solid fuels for cooking and heating, followed by industrial activities (14.8%), energy production (12.5%), and anthropogenic dust (11.5%) from construction and road dust. Agriculture (9.4%) and transport (6.7%) also play significant roles, while smaller contributions come from waste burning, other fires, commercial activities, solvents, and shipping.

One of the Major interventions India has introduced to reduce emissions from residential solid fuels is the Pradhan Mantri Ujjwala Yojana (PMUY). This program provided over 80 million subsidised LPG connections to low-income households. Studies have shown a significant reduction in pollution and associated health benefits after the program’s implementation. Despite the PMUY’s initial success in facilitating LPG access, sustaining its usage remains challenging. In India, one estimate suggests that eradicating air pollution caused by the use of solid fuels for cooking could enable the country to meet its national ambient air quality standard for PM2.5. Hence, it is essential to emphasise targeted interventions and address regional and community-specific disparities to promote the continued and sustained use of LPG, presenting a clear opportunity for further emission reduction.

Looking ahead

Collectively, exposure to ambient and household air pollution imposes a burden on public health and has significant economic and societal impacts. It is critical that initiatives under the National Clean Air Programme, along with other targeted sectoral actions, be implemented through scientifically driven and multisectoral cooperation to achieve clean air and better health for all.

For more details, visit https://www.stateofglobalair.org/.