If air pollution permanently reduced to meet WHO air quality guidelines, it would "add 2.2 years onto average life expectancy", researchers say.

In the Indian capital city of New Delhi, crippling lung and heart disease caused by PM2.5 pollution reduces life expectancy by a decade.
In the Indian capital city of New Delhi, crippling lung and heart disease caused by PM2.5 pollution reduces life expectancy by a decade. (AP Archive)

Microscopic air pollution caused mostly by burning fossil fuels shortens lives worldwide by more than two years, a report from the University of Chicago's Energy Policy Institute has shown.

"Clean air pays back in additional years of life for people across the world," lead researcher Crista Hasenkopf and colleagues said in the Air Quality Life Index report on Tuesday.

"Permanently reducing global air pollution to meet the WHO's guidelines would add 2.2 years onto average life expectancy."

PM2.5 pollution -- 2.5 microns across or less, roughly the diameter of a human hair -- penetrates deep into the lungs and enters the bloodstream. It was classified as a cancer-causing agent by the United Nations in 2013.

The World Health Organization says PM2.5 density in the air should not top 15 micrograms per cubic metre in any 24-hour period, or 5 mcg/m3 averaged across an entire year.

Faced with mounting evidence of damaging health impacts, the WHO tightened these standards last year, the first change since establishing air quality guidance in 2005.

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'South Asians would live five years longer'

Almost all populated regions in the world exceed WHO guidelines, but nowhere more so that in Asia: by 15-fold in Bangladesh, 10-fold in India, and nine-fold in Nepal and Pakistan.

Central and West Africa, along with much of Southeast Asia and parts of central America, also face pollution levels, and shortened lives, well above the global average.

Surprisingly, PM2.5 pollution in 2020, the most recent data available, was virtually unchanged from the year before despite a sharp slow-down in the global economy and a corresponding drop in CO2 emissions due to Covid lockdowns.

"In South Asia, pollution actually rose during the first year of the pandemic," the authors noted.

Across South Asia, the average person would live five years longer if levels of fine particulate matter met WHO standards.

One country that has seen major improvements is China. PM2.5 pollution fell in the nation of 1.4 billion people by almost 40 percent between 2013 and 2020, adding two years to life expectancy. But even with this progress, lives in China are on average cut short today by 2.6 years.

Compared to other causes of premature death, the impact of PM2.5 pollution is comparable to smoking tobacco, more than three times that of alcohol use, and six times that of HIV/AIDS, the report said.

Not a single country managed to meet the WHO's 5-microgram standard in 2021, according to a survey of pollution data published earlier this year.

READ MORE: 99 percent of world's population breathes poor-quality air: WHO

Source: TRTWorld and agencies