Air pollution shortens life expectancy in Bangladesh by average 4.8 years: WHO

Bangladesh is the world's most polluted country, and particulate air pollution (PM2.5) shortens the average Bangladeshi residents' life expectancy by 4.8 years, relative to what it would be if the World Health Organisation's (WHO) guideline of 5 µg/m³ were met, says a new global report released today (28 August).

It said some areas fare much worse than others, such as Gazipur and Narsingdi districts, where air pollution is shortening lives by more than six years.

Bangladesh's 166.4 million people live in areas where the annual average particulate pollution level exceeds the WHO guideline, and 96.8% of the population live in regions that don't 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% 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 one 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 spread across Dhaka and Chattogram, 75.9 million residents are on track to lose 5.4 years of life expectancy on average relative to the WHO guideline.

Global pollution 

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 WHO guideline, the average person would add 1.9 years onto their life expectancy – or a combined 14.9 billion life-years saved worldwide.

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 don't meet the standards that their countries have set.

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% of countries and territories worldwide have either not met or do not have a national standard. 

Trend reversal in 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% 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% 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 Organisation guideline.