A world of clean air

Air pollution is one of the most significant environmental health threats.

In an effort to achieve meaningful long-term reductions, the World Health Organization (WHO) recently published new air quality guidelines with revised levels for the “big six” most harmful pollutants:


Particulate matter (PM)


 Ozone (O₃)


Nitrogen Dioxide (NO₂)


Sulfur Dioxide (SO₂)


Carbon Monoxide (CO)


Although the new WHO Global Air Quality Guidelines (AQGs) are not mandatory, following them is seen as a key factor in improving global health.

Since the last update in 2005, evidence has strongly increased that air pollution affects many aspects of health. For this reason, all the previous maximum recommended levels have been reduced.

The pollution pandemic

Current estimates suggest that air pollution causes 7 million premature deaths worldwide every year, as well as causing the loss of millions more years of healthy life. These figures put air pollution in the same bracket as other major global health risks, such as obesity and smoking. In contrast, deaths from alcohol abuse look comparatively tame at 3 million a year.

The health risks associated with particulate matter in the 10 to 2.5 microns range (PM10 and PM2.5) are of particular concern. Both particle sizes are capable of penetrating deep into the lungs but PM2.5 can even enter the bloodstream. Prolonged or high exposure results in cardiovascular and respiratory disorders and can also affect other organs.

One in 10 deaths
caused by air pollution,
IS SOMEONE UNDER 15 YEARS OF AGE.

Unequal suffering

Westernized industrial countries generally have solid infrastructures to cope with the worst aspects of pollution.

Nevertheless, there are still notable hotspots. In Europe, for instance, multiple regions such as northern Italy and many Eastern European countries, as well as the densely populated Belgium, Netherlands and Luxembourg and parts of western Germany regularly experience increased pollution levels.

The goal of the revised guidelines is for all countries to achieve the new recommended air quality levels.

If these targets are met, it is estimated that around 80% of deaths related to PM2,5 could be avoided. But any meaningful reduction will certainly translate into wider health benefits.

However, the problem is particularly severe in low- and middle-income countries, which are experiencing growing levels of air pollution due to urbanization and economic development that largely relies on fossil fuels.

In 2019, more than 90% of the global population lived in areas where concentrations exceeded the 2005 WHO guidelines for long-term exposure to PM2,5.