The Energy Policy Institute at the University of Chicago, on Tuesday, released the Air Quality Life Index (AQLI) report which stated that air pollution stands as the "most significant external menace to human life expectancy," causing a reduction of the average worldwide lifespan by 2.3 years.
According to the report, air pollution causes more than three times the harm of alcohol and more than five times that of car crash injuries. Not a single country in the world fulfilled the World Health Organization's air quality criterion, which is 5 micrograms of pollutants per cubic metre of air (g/m3) in 2021.
Flagging the growing burden of hazardous air on human health, here are the key highlights from the report.
Asia and Africa: 'Air pollution poses greater threat than HIV/AIDS'
According to AQLI, most of the life expectancy loss due to air pollution occurs in Africa and Asia, which account for more than 92% of the global burden. In these continents, air pollution pose a bigger danger to public health than both malaria and HIV/AIDS put together. They do not, however, have the infrastructure required to monitor and enhance air quality.
Rapid industrialisation and growing population have contributed to deteriorating air quality in South Asia, where particle pollution levels are now more than 50% higher than at the turn of the century. These pollution levels have begun to outweigh the hazards posed by greater health threats.
According to Michael Greenstone, the creator of Air Quality Life Index, “Three-quarters of air pollution’s impact on global life expectancy occurs in just six countries, Bangladesh, India, Pakistan, China, Nigeria and Indonesia, where people lose one to more than six years off their lives because of the air they breathe.”
For instance, people in Bangladesh, the world's most polluted country, stand to lose 6.8 years of life on average per person, compared to 3.6 months in the United States. The researchers, therefore, advocated for increased funding and collaboration to "build the infrastructure that is missing today," particularly for timely, reliable, open-air quality data.
Delhi: The most polluted city in the world
According to the report, India, the second most polluted country after Bangladesh, is responsible for almost 59% of the global increase in pollution since 2013. The hazardous air threatens to shorten lives even further in some of the country's most polluted regions. Referring to New Delhi as the "world's most polluted mega-city", the report states that the average life span of Delhi residents has decreased by more than 11.9 years.
Closely followed by Delhi in this realm are cities like, Gurgaon (11.2 years), Faridabad (10.8 years), Jaunpur (10.1 years), Lucknow (9.7 years), Kanpur (9.7 years), Muzaffarpur (9.2 years), Prayagraj (8.8 years) and Patna (8.7 years).
It was found that Delhi's yearly average PM2.5 level in 2021 was 126.5 g/m3, which is more than 25 times the WHO's recommended level of 5 g/m3. This figure was a little lower in 2020, at 107 g/m3.
According to the report, particulate matter pollution poses the greatest risk to human health in India, outpacing cardiovascular illnesses and child and maternal malnutrition in terms of reducing life expectancy. “The average Indian resident is set to lose 5.3 years of life expectancy if the WHO guideline is not met,” the report read.
How is AQLI calculated?
The AQLI establishes a link between air pollution and life expectancy, providing an estimated figure as to how much longer a community may live if they fulfill WHO guidelines, national standards or some other standards.
The index draws on from the findings of two research conducted in China (here and here) in this regard. These research works provide a plausible mathematical equation to derive a life expectancy estimate, corresponding to the PM2.5 levels of the region. PM2.5 or particulate matter 2.5, refers to tiny inhalable particles or pollutants in the air that are 2 ½ microns or less in width.
These tiny pollutants are considered dangerous for health because they can get into the deep parts of our lungs, or even into our blood.
As many countries in the world currently lack extensive pollution monitoring systems, AQLI relies on satellite-derived data on PM2.5 concentration spanning 24 years from 1998-2021. For this purpose, the surface of the Earth is divided into grid cells no bigger than 6 km x 6km, and the dataset provides the PM2.5 concentration over each of these grid cells.