Home ›› Environment
Bangladesh is the world's most polluted country, and fine particulate air pollution (PM2.5) shortens the average Bangladeshi resident's life expectancy by 4.8 years, relative to what it would be if the World Health Organization (WHO) guideline of 5 µg/m³ was met, says a new global report.
Some areas of Bangladesh fare much worse than others, such as the Gazipur and Narsingdi districts, where air pollution is shortening lives by more than 6 years, it stated.
Key takeaways
All of Bangladesh's 166.4 million people live in areas where the annual average particulate pollution level exceeds both the WHO guideline and 96.8 per cent of the country's population live in regions that do not meet the country's own national standard of 35 µg/m³.
Even in the least polluted district of Sylhet, particulate pollution is 6.7 times the WHO guideline.
While particulate pollution takes 4.8 years off the life of the average Bangladeshi, tobacco use takes off 2 years and child and maternal malnutrition takes off 1.4 years.
In 2022, particulate pollution was 22 percent lower relative to 2021-a contrast to the increasing trend between 2015-2021.
If the reduction in 2022 is sustained, an average Bangladeshi resident would live 1 year longer compared to what they would if they were exposed to the average pollution levels over the last decade.
In some of the most polluted districts of the country spread across the states of Dhaka and Chittagong, 75.9 million residents or 45.6 percent of Bangladesh's population are on track to lose 5.4 years of life expectancy on average relative to the WHO guideline.
If Bangladesh were to reduce particulate pollution to meet the WHO guideline, residents in Dhaka-the most populous district in Bangladesh-would gain 5.6 years of life expectancy.
In Chattogram, the country's second most populous district-residents would gain 5.2 years.
If pollution levels in Dhaka and Chattogram are to meet Bangladesh's national standard, life expectancy in these districts would increase by 2.6 and 2.3 years, respectively.
Greatest external risk to human health
While pollution slightly dipped due largely to a trend reversal in South Asia, more than three-quarters of countries around the world have not set or aren't meeting national pollution standards.
Though global pollution was slightly lower in 2022, its burden on life expectancy remains, according to new data from the Air Quality Life Index (AQLI).
If the world were to permanently reduce fine particulate pollution (PM2.5) to meet the World Health Organization's (WHO) guideline, the average person would add 1.9 years onto their life expectancy-or a combined 14.9 billion life-years saved worldwide.
This data makes clear that particulate pollution is the world's greatest external risk to human health. Its impact on life expectancy is comparable to that of smoking, more than 4 times that of high alcohol use, more than 5 times that of transport injuries like car crashes, and more than 6 times that of HIV/AIDS.
Yet, the pollution challenge worldwide is vastly unequal, with people living in the most polluted places on earth breathing air that is six times more polluted than the air breathed by those living in the least polluted places-and seeing their lives cut short by 2.7 years more because of it.
"While air pollution remains a global problem, its largest impacts are concentrated in a relatively small number of countries-cutting lives short several years in some places and even more than 6 years in some regions," says Michael Greenstone, the Milton Friedman Distinguished Service Professor in Economics and creator of the AQLI along with colleagues at the Energy Policy Institute at the University of Chicago (EPIC).
"All too often, high pollution concentrations reflect low ambition in setting policy or a failure to successfully enforce existing policies. As countries balance their economic, health, and environmental goals, the AQLI will continue to shine a light on the longer lives that air pollution reductions deliver."
National standards are an important tool to set strong policies and improve air quality. These standards-some strong and some weak-reflect the multiple policy goals countries have as they balance economic, environmental and health goals.
However, a third of the world's population lives in regions that do not meet the standards that their countries have set. If those countries did meet their own benchmarks, these 3 billion people would live an average of 1.2 years longer.
"Setting ambitious standards is only one part of the puzzle," says Tanushree Ganguly, the director of the AQLI. "Equally important is implementing policies and monitoring mechanisms that help enforce these standards. Some countries are succeeding in this, and that gives proof that air pollution is a solvable problem."
While 37 out of 94 countries with standards aren't meeting them, more than half of all countries and territories have not set a standard at all. Together, 77 percent of countries and territories worldwide have either not met or do not have a national standard.
Of the countries with no standard, almost none (less than 1 percent) of the governments provide fully open pollution data and two-thirds don't have any government pollution monitoring. With little data, it is difficult to set pollution standards and enforce them.
To help confront this challenge, this year EPIC launched the EPIC Air Quality Fund to support local groups and organizations in installing monitors and providing open data to communities that could benefit the most.
"Highly polluted countries that have little or no air quality data often fall into a bad feedback cycle where having little data leads to little attention or policy investment in the issue which reinforces little demand for data," says Christa Hasenkopf, the director of the Clean Air Program at EPIC.
"Fortunately, there is a massive opportunity to stop this cycle with even a small amount of persistent, open air quality data. Such data has been shown to be essential for crafting and reinforcing national standards."
South Asia
Global pollution declined in 2022 due almost entirely to a trend reversal in South Asia. While pollution had been on the rise for more than a decade, it declined by 18 percent in one year.
While it's difficult to know for sure the reasons for this decline, meteorological causes-such as above-normal rainfall-likely played a strong role and only time will tell whether policy changes are having an impact.
Even with the decline, the region remains the most polluted in the world, accounting for 45 percent of total life years lost due to high pollution.
The average person living in these countries would gain 3.5 years onto their lives if pollution were permanently reduced to meet the World Health Organization guideline.
