IQAir releases its annual World Air Report, and the 2021 figures are no mean feat. No country meets the WHO air pollution limit and only 3% of cities stay within the standards. Looking at Belgium’s figures, only 2 cities meet the imposed standards: Vielsalm and Habay.

Air pollution is considered the world’s greatest environmental health threat and is responsible for as many as seven million deaths per year around the world. Air pollution causes and exacerbates many diseases ranging from asthma to cancer, lung disease and heart disease. Recognizing the significant impact of air pollution on global health, the World Health Organization (WHO) has cut the recommended annual PM2.5 concentration in half by September 2021, from 10 to 5 micrograms, with the ultimate goal of preventing millions of deaths.

What are PM2.5?

PM2.5 are harmful, fine, inhalable particles up to 2.5 micrometers in diameter that are dangerous because they can enter deep into the respiratory tract. PM2.5 is generated by many sources and can vary in chemical composition and physical characteristics. Common chemical constituents of PM2.5 are sulfates, nitrates, black carbon and ammonium. The most common man-made sources are internal combustion engines, electricity generation, industrial processes, agricultural processes, construction, and residential wood and coal burning. The most common natural sources of PM2.5 are dust storms, sandstorms and forest fires.

World Air Report

The World Air Report shows that only 2 cities in Belgium meet the guidelines: Vielsalm and Habay, both in southern Wallonia. But we are not the only ones who do not comply. In 6253 of the 6475 cities and towns surveyed, air pollution exceeds WHO standards. At the national level, there is no country whose average air quality meets WHO standards. In only 3 territories is the air found to be clean enough: New Caledonia, the US territory of Puerto Rico and the US Virgin Islands.

What can we do about it?

It is primarily up to governments to reduce air pollution emissions. This can be done, for example, by passing legislation to encourage the use of clean vehicles for personal and industrial use, by investing in renewable energy sources, by building infrastructure to encourage pedestrian and bicycle travel, …


You can support local and national initiatives, proposals, measures, organizations, etc. that advocate for better air quality. But you can also reduce your own personal energy consumption, reduce your amount of waste by recycling, or choose greener modes of transportation.