How much longer can you live if you breathe clean air?

By Aarsh Batra

The life expectancy of an average person on the planet would have extended by 2.3 years had the particle pollution from 2021 levels been lowered to match the WHO guideline, according to the satellite-derived data from the 2023 Air Quality Life Index (AQLI). 

The WHO recommended guideline for annual average PM_2.5   is 5 micrograms per cubic meter (µg/m³). The burden of pollution is not spread evenly throughout the world—nor are the basic resources necessary to build strong policies to tackle it.

Although a few regions, like Melbourne, Australia, conform to the WHO guideline, the AQLI report finds that 98.4% of the world’s population is living in regions that are out of compliance with the WHO guideline, revealing a pattern of stark air inequality across the world as can be seen in the map. For instance, Delhi residents lose nearly 12 years on average, Warsaw residents lose 1.2 years, and in Los Angeles, 7.8 months of life are lost as a result of long-term sustained exposure to pollution levels that are not in compliance with the WHO guideline.

Air pollution is the world’s largest environmental risk factor for disease and premature death, which disproportionately harms residents of low and middle-income countries. But, to the majority of the global population, air pollution seems like an inescapable fact of life that surrounds us, leaving us with little choice but to breathe it in and bear the negative health consequences. 

How does the threat from particle pollution compare with other global health threats?

Measured in terms of life expectancy, the AQLI reveals that ambient particulate pollution is consistently the world’s greatest external risk to human health.

While particulate pollution is set to reduce global average life expectancy by 2.3 years, tobacco use reduces global life expectancy by 2.2 years; unsafe water, sanitation and handwashing by 0.6 years; and nutritional deficiencies by just 0.1 years.

Thus, the impact of particulate pollution on life expectancy is 3.8 times that of unsafe water sanitation and handwashing, and 23 times that of nutritional deficiencies.

What is Particulate matter and why is it dangerous?

Particulate matter (PM) consists of minuscule solid and liquid particles like soot, smoke, and dust suspended in the air. The finer particles, such as PM_2.5 with a width of less than 2.5 μm (micrometers), are exceptionally dangerous. To illustrate, the width of a single PM_2.5 particle is just a fraction of the width of an average human hair – it would take around 33 of these particles lined up to match that width. This minuscule size allows them to infiltrate the bloodstream through the lungs’ alveoli, triggering inflammation, constricting blood vessels, dislodging fatty plaque, and elevating blood pressure. This can over time lead to strokes, heart attacks, and an increased risk of lung disease.

For an interactive version of the map featuring data from 1998 to 2021 across different geographical scales, visit the AQLI website at https://aqli.epic.uchicago.edu/the-index/. 

Source:  Air Quality Life Index, Annual Report 2023, Energy Policy Institute at the University of Chicago (EPIC).