Cutting air pollution levels could raise life expectancy by 2 years: study

Reducing global air pollution levels to meet the World Health Organization’s (WHO) guidelines would boost average life expectancy by 2.2 years, a new study has found.

The average person is exposed to more than three times the air pollution deemed acceptable by the WHO — driving average life expectancy down from 74 to 72 years old, according to the Air Quality Life Index (AQLI), compiled by researchers at the University of Chicago.

With universal changes in behavior to meet WHO standards, however, global citizens could collectively add 17 billion life-years to the planet’s population, researchers found.

The authors maintained that these figures were an opportunity, rather than a sign of doom, after witnessing the dramatic improvements implemented by one country in particular — China.

“The improvements that China was able to bring about in such a short period of time: six or seven years or so,” Kenneth Lee, the director of the AQLI, told The Hill. “Whereas, it took decades for the U.S. to make those changes.” 

“That really speaks to China’s singular ability to address major environmental issues, as long as they see the importance of it,” added Lee, who is a senior research associate at the University of Chicago’s Department of Economics.

WHO air quality guidelines indicate that levels of PM 2.5 — fine particulate matter with a diameter of less than 2.5 micrometers — should be below 10 micrograms per cubic meter. The average global citizen, however, is exposed to concentrations of 32 micrograms per cubic meter, according to the study.

PM 2.5, which is 30 times smaller than the diameter of a single human hair, can get deep into the lungs and sometimes into the bloodstream and cause serious health problems, according to the Environmental Protection Agency. 

The authors compiled the AQLI by using existing, high-resolution satellite data generated by a research team at Washington University in St. Louis. The data provides measurements of aerosol optical depth — or how much light is coming back to the sensor — with less light suggesting that more pollution is present, Lee explained.

After acquiring the satellite data, they calibrate the findings with ground-level monitors to assess accuracy, and have found a strong correlation with their results, according to Lee.

In South Asia in particular — where four out of the five countries with the greatest PM 2.5 concentrations are located — the authors found the greatest opportunities for change. AQLI data revealed that the average person living in India, Bangladesh, Nepal and Pakistan would live 5.6 years longer if pollution was reduced to meet the WHO guideline.

Singapore, the fifth country, could expect 3.8 additional years for its residents if such a shift occurred. Despite Singapore’s advanced environmental policies, the tiny island city-state sits in the middle of a highly polluted region and is affected by peat fires on the Indonesian island of Kalimantan, Lee explained.

Several densely populated cities in Southeast Asia — Bangkok; Ho Chi Minh City, Vietnam; and Jakarta, Indonesia — could see average increases in two to five years of life per person, if these locations met WHO guidelines, the report said.

In Central and Western Africa, the AQLI found that the effects of particulate pollution on life expectancy were on par with those of threats like HIV/AIDs and malaria. Residents of the Niger Delta region of Nigeria specifically were on course to lose about six years of life expectancy if current trends persist, the study showed.

More than half of the 611 million residents of Latin America are exposed to PM 2.5 levels that exceed the WHO guideline, the air quality report noted. If certain metropolitan hot spots reduced their air pollution — mostly caused by vehicle emissions — citizens could see significant life expectancy surges: 4.7 additional years in Lima, Peru, 1.8 in Bogota, Colombia, and 2.2 in Medellín, Colombia, the study found.

The coronavirus pandemic may have offered a preview of what cleaner air could feel like, as lockdowns in Northern India, for example, allowed communities to see “the snow-capped Himalayas for the first time in years,” according to the authors.

The researchers expressed optimism that such massive improvements could occur due to the dramatic success over the past decade in China. They went so far as to characterize China as “winning its ‘war against pollution,’ ” waged by Chinese Premier Li Keqiang in 2013.

Since then, pollution has dropped by 29 percent, adding about 1.5 years onto average life expectancy, according to the study.

“It took several decades and recessions for the United States and Europe to achieve the same pollution reductions that China was able to accomplish in six years, even as it continued to grow its economy,” the authors wrote.

Lee said that while China is not a democracy, the country’s approach toward air pollution was remarkably democratic — fueled by a “demand for change” that began following the 2008 Olympics.

“China is a really good benchmark,” he added. “The government of China responded to pressure from its own citizens.”

Lee said he saw prospects for similar change in India in particular, where momentum has been rising and where the government launched a national clean air program in 2019.

A shift in Bangladesh, Nepal and Pakistan might come a bit slower, he acknowledged, due to the lack of awareness, air quality sensors and funding. 

“There’s a role for donors to step in and fill these information gaps,” Lee said. “Governments sometimes face incentives to not want to expose an issue that would be difficult to resolve right away.”

Although the world’s most polluted spots experienced clear skies during the pandemic, the authors stressed that Americans encountered wildfires that “sent clouds of smoke to cities thousands of miles away.” This reality, according to Lee, makes the air quality index relevant to America, even though average PM 2.5 levels aren’t high in comparison.

With a drier climate and increased temperatures, wildfires like those raging in California are generating episodes of heavy smoke, leading to potential increases of annual PM 2.5 concentrations on a regional basis, he explained. 

And those rises in concentrations, according to the study’s authors, are caused not only by the real-time smoke itself, but also by the human-induced climate change that is laying the foundation for such conditions. 

“This is something we should care about because we’re reducing the life expectancy of our children under the scenario where no action is taken to reduce fossil fuel combustion,” Lee said. “It might be a sign of things to come.”