Levels of particulate matter in the air declined in South Asia including India in 2022 after years of continuous increase, shows new research by the Energy Policy Institute at the University of Chicago – EPIC. Yet, air quality in South Asia remains poor and many cities do not even comply with their national air quality standards, let alone the more stringent standards set by the World Health Organization.
Global pollution declined in 2022 almost entirely due to the 18% decline in levels in South Asia – and to a lesser extent, the 4.8% decline in Southeast Asia, researchers found. If not for these declines, global pollution levels would have remained the same as in 2021.
The South Asian decline from 2021 to 2022 is the largest single year decline for a region since the beginning of data collection in 1998. If this progress is sustained, EPIC estimated, it would translate into 0.9 years of life expectancy gained compared to 2021 levels.
Particulate matter measuring less than 10 micrometre in diameter has the ability to penetrate deep into the respiratory system, as IndiaSpend reported in October 2023 Among these particles, those with a diameter of less than 2.5 micrometre, known as PM 2.5, pose the most significant health risk. PM 2.5 particles are capable of infiltrating the lungs and occasionally entering the bloodstream, resulting in serious health consequences.
Air quality and your life expectancy
Air pollution is a cause of health ailments around the world. As winter approaches in the coming months, parts of India’s northern plains including the national capital region are likely to see poor air quality levels as has been the trend in the last decade or so.
Sustained exposure to air pollution can cause respiratory illnesses, heart disease, increased cerebrovascular risk and people with existing respiratory illnesses, pregnant women and children are especially vulnerable, IndiaSpend had reported in 2022.
Even short-term exposure to air pollution was seen to cause premature deaths among the elderly in the US, IndiaSpend reported in January 2018. An increase of just 1 microgram per cubic metre of air (µg/m³) in daily PM 2.5 over the course of one summer in the US would lead to 550 more deaths per year, we had reported.
A new study indicates a potential elevation in the risk for type 2 diabetes associated with exposure to PM 2.5, IndiaSpend reported in November 2023.
The impact of PM 2.5 on global life expectancy is comparable to that of smoking, 1.3 times that of childhood and maternal malnutrition, 4.4 times that of high alcohol use, 5.8 times that of transport injuries like car crashes and unsafe water, and 6.7 times that of HIV/AIDS, the EPIC report noted, citing data from the Global Burden of Disease database.
In India, air pollution is a major subject of political debate as well. This year, both the Congress and the Bharatiya Janata Party had prominently featured it in their election manifestos ahead of the general election this summer.
After a decade of PM 2.5 levels averaging at approximately 49 μg/m³ – more than nine times the World Health Organization guideline of 5 μg/m³ – annual average PM 2.5 concentrations in India dropped to 41.4 μg/m³ in 2022, EPIC data show.
If these reductions are sustained, an average Indian is likely to live nine months longer compared to what they would have if they were exposed to levels similar to the last decade, researchers noted. This estimation is based on the Air Quality Life Index, which translates particulate air pollution into its impact on life expectancy. Developed by a team of researchers led by economics professor Michael Greenstone of the University of Chicago, the Index shows that if pollution standards in India met the WHO guidelines, Indian citizens could gain an additional 3.6 years of life expectancy.
Bangladesh and Nepal also saw significant decline in pollution. In some districts of Dhaka and Chittagong in Bangladesh and West Bengal and Jharkhand in India, reductions in PM 2.5 concentrations relative to 2021 are higher than 20 μg/m³.
But how did South Asia’s air quality improve in 2022? Good rainfall could be a factor but researchers noted that they cannot conclusively determine the exact reasons. For India in particular, a nation-wide roll out of its clean cooking programme, the Pradhan Mantri Ujjwala Yojana, and decrease in use of diesel in the transport sector have also been contributing factors, the report said
“No country in the world – whether the United States, China, or Japan – has successfully reduced pollution without implementing forceful policies and making deliberate efforts to enforce standards,” Tanushree Ganguly, director of Air Quality Life Index and also a co-author of the EPIC report, told IndiaSpend.
“Fortunately, in India, there are already some promising developments, such as the industrial emission trading scheme currently being implemented in Gujarat. It is the world's first particulate pollution market, aimed at tackling the dual challenges of cleaning the air while supporting robust economic growth.”
The pilot emission trading scheme mentioned here was implemented in Surat in 2019 and resulted in industries reducing their particulate matter pollution by 24% compared to industries that continued to be under the business-as-usual regulation, we reported in 2021.
Long way to go
South Asia remains the world’s most polluted region, accounting for 45% of the total life years lost globally due to high pollution. In Bangladesh, India, Nepal and Pakistan – where 23.2% of the global population lives – the impact of particulate pollution on life expectancy is substantially higher than that of other large health threats, the report noted.
The average resident of Bangladesh, India, Nepal and Pakistan is exposed to particulate pollution levels that are 22.3% higher than at the turn of the century. This led to an additional 0.7 years lost in life expectancy, the report estimated.
Despite a 19.3% drop in particulate levels in 2022 compared to 2021, an average resident in India is likely to lose 3.4 years of life expectancy if pollution levels persist. In particular, the average resident of the northern plains is still likely to lose about 5.4 years of life expectancy.
India has a goal to reduce air pollution levels across the country by 40% by 2026 as part of the National Clean Air Programme which covers 131 non-attainment cities. If India were to meet this target, the residents in the non-attainment cities will see their life expectancy increase by two years compared to 2017. India’s national average life expectancy will also increase by an additional 7.8 months as a result.
In that case, should our national air quality standards be made more stringent on the lines of WHO standards? “National Ambient Air Quality Standards should be reviewed periodically and weigh in emerging evidence on impact of air pollution on health,” said Ganguly of EPIC.
Our national targets need to also focus on rural areas, which experts have repeatedly pointed as crucial.
This article first appeared on IndiaSpend, a data-driven and public-interest journalism non-profit.
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