India’s Air Pollution Challenge Spans Rural and Urban Areas

Co-authored by Rachit Sharma, 2023 India Science and Health Intern

Across the globe, the health burden of air pollution from burning fossil fuels is substantial, resulting in increased risk of premature mortality, reduced life expectancy, and decreased quality of life. Scientists estimate that air pollution was responsible for at least 7 million deaths globally in 2019, ranking as the fourth highest risk factor for premature mortality, surpassed only by high blood pressure, dietary risks, and tobacco usage. Reducing air pollution and transitioning to cleaner and renewable energy sources is crucial for protecting public health and promoting sustainable development. Developing countries like India are leading this charge, but air quality challenges persist.

Air pollution remains a pressing public health concern in India, threatening both rural and urban populations. A recent report by Climate Trends reveals high levels of fine particulate matter (PM_2.5)—one of the most dangerous forms of air pollution—throughout the country, indicating that air pollution is not confined to specific urban regions but is, in fact, a nationwide issue.

Air Pollution Knows No Boundaries

This new analysis of fine-scaled satellite data reveals that air pollution is a pervasive problem in India. Last year’s annual PM_2.5 air pollution averages for both rural and urban areas continue to exceed the annual limit of 40 µg/m³ in India set by the Central Pollution Control Board and are well above the World Health Organization’s recently revised Air Quality Guidelines of 5 µg/m³:

The encouraging news is that this analysis indicates that nationally averaged PM_2.5 levels in rural and urban areas across India have both declined to similar extents (about 19 percent) over the past five years. The report illuminates important geographical differences in air pollution trends across the country. Among Indian states, Uttar Pradesh has shown remarkable progress in air pollution control, with urban PM_2.5 levels reduced by 37.8 percent and rural levels by 38.1 percent between 2017-2022. In contrast, Maharashtra experienced only a marginal 7.7 percent decline in urban PM_2.5 levels and Gujarat achieved an 8.2 percent reduction in rural PM_2.5 levels. Among union territories, Chandigarh was the only one that witnessed a slight increase of 0.3 percent in urban PM_2.5 levels.

The northern and eastern regions performed better than the South and West. Specifically, the western region witnessed only a 10.6 percent reduction in urban PM_2.5 levels and an 11% reduction in rural PM_2.5 levels. On the other hand, the eastern region demonstrated the most notable improvement, with urban PM_2.5 levels decreasing by 20.4 percent and rural PM_2.5 levels decreasing by 22.5 percent. However, it is worth noting that while the air pollution levels across north India get the majority of the media attention, PM_2.5 levels are still exceeding the 40 µg/m³ cut-off in rural and urban areas in all regions except the south:  

Another key finding from this report is that, across all regions, rural areas have experienced stronger reductions in PM_2.5 levels compared to urban areas. This finding may, in part, be attributable to the progress made under the Pradhan Mantri Ujjwala Yojana. This initiative, launched by the Indian government in 2016, aims to provide clean cooking fuel, specifically liquefied petroleum gas, to women in socioeconomically disadvantaged households to reduce household air pollution generated by burning solid fuels such as wood, coal, and biomass for cooking, heating, and lighting needs. However, a significant portion of the rural population in India still depends on solid fuels and estimates suggest that PM_2.5 emissions from household sources contribute about 30 to 50 percent of overall ambient PM_2.5 levels in the country.

Persistent Challenges and Health Harms

The declines in PM_2.5 levels over the past years are encouraging in light of India’s ambitious National Clean Air Progamme (NCAP) goals, which aim to reduce PM_2.5 pollution substantially by 2024,but also highlight the importance of air pollution issues outside of urban settings. The objective of the NCAP is to substantially decrease air pollution levels in cities across the country that currently surpass India's National Ambient Air Quality Standards established to safeguard public health with an acceptable level of safety. India’s Ministry of Environment, Forests, and Climate Change has set a national target of reducing annual levels of PM_2.5 by 20-30 percent by 2024, relative to a 2017 baseline. However, as of 2023, four years into NCAP implementation, the progress made so far is inconsistent and falls short of achieving the desired results by 2024. Air pollution is not confined to geographical boundaries and requires a comprehensive approach beyond the scope of urban-focused programs like the NCAP. 

Furthermore, it is important to acknowledge that these declines in dangerous air pollution levels need to continue because the current, absolute PM_2.5 levels remain unhealthy. The concerning trend holds true when comparing states that are with or without ‘non-attainment cities’ included under NCAP, suggesting that many Indians are being exposed to long-term air pollution that is responsible for a range of dangerous health impacts, including respiratory diseases, cardiovascular diseases, neurological disorders, and premature death. According to the 2022 State of Global Air Report, at least 1.6 million deaths were attributable to air pollution alone in India in 2019, making it the leading environmental hazard in the country. A separate analysis estimated that in 2019, the economic losses in India resulting from premature deaths and illnesses linked to air pollution were estimated to be $ 29 billion and $8 billion, respectively.

Leveraging Satellite Data for New Insights

India’s air pollution monitoring network is still limited but quickly growing, and this new analysis highlights the value of satellite data in tracking air pollution trends. Satellite-derived PM_2.5 levels provide comprehensive insights into pollution patterns and their sources, enabling a better understanding of air quality in both rural and urban areas. This information is vital for designing targeted interventions and implementing effective mitigation strategies.

However, since rural areas are often excluded from air quality monitoring programs, reliance on the current network of air monitors to validate satellite-derived data can result in biased results that do not adequately capture rural pollution levels. To improve the interpretation of satellite data, the establishment of a denser rural air monitoring network is crucial. To accurately reflect air quality trends, experts estimate that India needs a minimum of 4,000 monitoring stations, with 2,800 stations in urban areas and 1,200 stations in rural ones. This target is well above the NCAP national target of 1,500 stations by 2024. A robust monitoring network can be supplemented by long-term chemical speciation sites to identify pollution sources accurately for targeted mitigation efforts. At the household level, conducting systematic surveys and utilizing sensor-based monitoring can help capture shifts in fuel choices. By enhancing the reach of ground-level air monitoring data, policymakers can obtain a more nuanced understanding of air pollution in different regions and develop more effective strategies to address priority sources.

Towards Cleaner Air for All

Overall, this new report underscores the value of satellite data in tracking pollution trends and highlights the importance of addressing pollution sources in both rural and urban settings to safeguard public health in India. Despite differences in sources of air pollution, observed levels of PM_2.5 are similarly high in both urban and rural areas. As a result, both urban and rural populations alike face health risks from breathing in contaminated air. It is worth noting that air pollution is often seen as an issue primarily affecting urban areas, resulting in less media attention being given to rural regions, even though rural areas encompass about 64 percent of the country's population.

This new analysis of PM_2.5 levels highlights the urgency of addressing this issue through comprehensive and targeted measures. Primary sources of PM_2.5 in India include household emissions, power sector emissions, industrial activities, transportation, open burning of crops and waste, and dust. Household emissions have a dominant role throughout India, while vehicular exhaust and dust resuspension are the primary local sources in Indian cities. Although most PM_2.5 sources in urban areas are local, non-local contributions can be significant. In Delhi, for example, local sources account for around 70 percent of total PM_2.5, with non-local sources contributing over 30 percent, especially during winter. Air quality management should extend beyond urban areas to address pollution sources in both rural and urban settings. Shifting the air pollution management mindset away from highly localized areas towards broader airsheds is needed because addressing pollution sources across multiple sectors can help to deliver air quality gains that are more widespread, equitable, and sustainable over the long term. 

Continued efforts to document the evolving nature of air pollution emissions and exposures in India are needed, and by leveraging scientific knowledge, including the quantification of the related health effects, India can work towards cleaner air and a healthier future for all of its people.