According to CNBC, the Air Quality Life Index (AQLI) shows that on a global scale, air pollution is taking some 17 billion years from us, and by reducing air pollution around the world, life expectancy would grow from 72 to 74.2 years.

The report says that firsthand smoking reduces life expectancy by 1.9 years on average, while alcohol and drug use reduce it by nine months.

Among other life-threatening elements, researchers report that malaria reduces life expectancy by three months and conflict and terrorism by seven days.

Air pollution is very dangerous in particular for people who live in heavily polluted area, since they can't do much to protect themselves from its dangerous effects.

"Whereas it is possible to quit smoking or take precautions against diseases, everyone must breathe air. Thus, air pollution affects many more people than any of these other conditions", the report says.

When it comes to the ratio of each pollutant matter, 60% of air pollution comes from fossil-fuels, 18% comes from natural sources, which can include dust, sea salt and wildfires, and 22% comes from other human activities.

The report was made by Michael Greenstone from the University of Chicago and his team back in 2020, when human activity and transport were reduced due to lockdowns.

South-east Asia feels the effects of pollution the most, with countries like India, Pakistan, Bangladesh and Nepal being among the most polluted countries in the world. In this area of the world, pollution levels have increased even by 25%.

Particulate matter air pollution is categorized by its size and generally, the smaller it is, the deeper it can go in the body. Particulate matter with a diameter of less than 10 micrometers can pass through the hairs in the nose and get into the lungs.

Particulate matter with a diameter of 2.5 micrometers can reach deeper parts of the body, being able to go all the way into the blood stream.

The World Health Organization first published its safety guidelines for air quality back in 2005, when it said that the acceptable levels of air pollution was less than 10 micrograms per cubic meter.

Nearly every person on Earth is in affected by air pollution

Last year in September, the organization changed the benchmark to under 5 micrometers per square meter.

Right now, more than 97% of the world population, meaning 7.4 billion people, lives in places where air quality doesn't pass the recommended 5 micrometers per cubic meter.

Greenstone, who was previously the chief economist for former President Barack Obama’s Council of Economic Advisers, said that "this report reaffirms that particulate pollution is the greatest global health threat. Yet we also see the opportunity for progress. Air pollution is a winnable challenge. It just requires effective policies."

China is a country that was able to dramatically reduce air pollution, after it registered record levels of pollution back in 2014. The government was able to reduce particulate pollution by 39.6%.

Despite this progress, China is still above the recommended air pollution levels from the WHO.

"It is important to note that air pollution is also deeply intertwined with climate change. Both challenges are primarily caused by the same culprit: fossil fuel emissions from power plants, vehicles, and other industrial sources", the report says.

Air pollution on a global scale

According to the study, the global level of PM 2.5 particle pollution decreased from 27.7 micrograms per cubic meter to 27.5 between 2019 and 2020, meaning that the global average is still more than five times higher than what the WHO recommends.

In south Asia, which is the most populated region on Earth, people are expected to lose about five years of their life expectancy if conditions are not improved.

Still, some countries recorded lower levels of pollution in 2020, Indonesia being one of them, as pollution levels in the country decreased by 20% year over year, due to the reduction of fire-related smoke.

Compared to 2019, 2020 saw smaller pollution levels in Russia, China, Germany and Japan.

Still, despite some countries experiencing overall increases in particulate pollution, regions from those countries might actually see a decrease in air pollution.

Christa Hasenkopf, AQLI’s director, said that "while India’s year-on-year average particulate pollution levels increased by 2.9%, Delhi experienced a roughly 6% decrease in particulate pollution from 2019 to 2020."

Some of the countries that saw worse levels of pollution around the world are Bangladesh, Nigeria, Pakistan and the US.