Fine particle pollution, created by burning fossil fuels, shortens lifespans and remains a leading health risk worldwide. Scientists have tracked its impact for years, confirming that atmospheric pollution is a major cause of preventable deaths across the globe.
In South Asia, life expectancy would improve by roughly five years if PM2.5 levels met World Health Organization standards, according to a study cited by researchers from the Energy Policy Institute at the University of Chicago and reported by AFP.
In the Indian states of Uttar Pradesh and Bihar, where about 300 million people live, lung and heart diseases linked to PM2.5 have shaved years off life expectancy, with notable impacts concentrated in the national capital, New Delhi, over the past decade.
PM2.5 refers to particles 2.5 microns in diameter or smaller, about the width of a human hair. These tiny particles largely originate from vehicle exhaust and can penetrate deep into the lungs and enter the bloodstream.
In urban health imagery, the pollution seen in large cities underscores the scale of the problem.
In 2013, the United Nations classified PM2.5 as a carcinogen. The World Health Organization advises that PM2.5 should not exceed 15 micrograms per cubic meter over 24 hours, nor an annual average of 5 micrograms per cubic meter. These guidelines have guided global efforts to curb air pollution.
Facing mounting evidence of harm, WHO tightened these standards last year, marking the first update to air quality guidance since 2005.
Clean Air Extends Lifespan
Researchers reporting in the Air Quality of Life Index found that cleaner air adds years to life worldwide. The lead author and colleagues noted that reducing global air pollution to meet WHO guidelines could add about 2.2 years to global life expectancy on average.
While many populated regions exceed WHO guidelines, Asia shows particularly high exposure: notable disparities include Bangladesh, India, Nepal, and Pakistan reporting elevated PM2.5 levels. Regions in Central and West Africa, much of Southeast Asia, and parts of Central America also show pollution levels well above the global average, correlating with shorter lives.
Data from 2020 reveal that pollutant levels remained largely steady despite a global economic slowdown and reduced CO2 emissions during COVID lockdowns. The researchers observed that pollution rose in the first year of the pandemic in South Asia, highlighting the uneven impact of crisis periods on air quality.
Urban transport remains a major emitter of fine particles, contributing to higher exposures in cities around the world.
A recent assessment highlights China as a case of both progress and ongoing challenges. PM2.5 pollution declined by about 40% from 2013 to 2020 in a country with over a billion people, contributing to a measurable increase in life expectancy. Yet overall life expectancy trends remain affected by pollution levels in different provinces and by the continued strain on air quality in some areas.
Compared with other preventable risks, PM2.5 exposure has a significant mortality impact, estimated to be comparable to the effects of smoking and materially larger than several other well-known risk factors.
Spain’s Regional Trends
In Spain, regions have worked to reduce PM2.5 and related pollutants, aligning with WHO recommendations. Analyses show that most autonomous communities lowered their average annual PM2.5 concentrations between 2010 and 2020, though adjustments to the WHO guideline of five micrograms per cubic meter gradually shifted the threshold expectations across the board. PM10 trends varied by region, with some areas seeing increases while others stayed below the WHO guideline of 15 micrograms per cubic meter.
Across the landscape of air quality, experts emphasize ongoing monitoring and policy refinement to sustain gains in public health and longevity. Ongoing research and international collaboration continue to push for cleaner air as a pathway to longer, healthier lives across communities.
Notes on data and guidance come from health authorities and scientific collaborations that monitor air quality and its health impacts, offering a basis for policy decisions and personal risk reduction strategies. These insights reinforce the importance of clean air as a public health priority and a practical pathway to extending life expectancy.