Geneva (AFP)

Asthma, lung infections, stroke ... Air pollution kills 7 million premature deaths per year, prompting the WHO to establish more restrictive limits for the main air pollutants, including airborne particles.

This is the first time that the WHO has updated its global air quality guidelines since 2005.

Since then, new data has shown "how air pollution affects all parts of the body - from the brain to the growing baby in its mother's womb, and at even lower concentrations than previously seen," he said. WHO Director General Tedros Adhanom Ghebreyesus said at a press conference.

"There is nothing more essential to life than air. And yet, because of air pollution, the simple act of breathing causes 7 million deaths per year", mainly due to non-communicable diseases, he added.

This is why the WHO has lowered almost all of its reference thresholds - legally non-binding - which mainly relate to so-called classic pollutants: suspended particles, ozone, nitrogen dioxide, sulfur and carbon monoxide.

- One of the main environmental threats -

"Air pollution is a threat to health in all countries, but it mostly hits people in low and middle income countries," said Dr Tedros, as disadvantaged countries face increasing levels. air pollution, boosted by large-scale urbanization and economic development that relies primarily on the use of fossil fuels.

For Dr Hans Henri Kluge, WHO Regional Director for Europe, "clean air should be a fundamental human right and a necessary condition for the health and productivity of societies".

Along with climate change, air pollution is, according to the WHO, one of the main environmental threats to health.

A few weeks before the decisive COP26 summit in Glasgow, Maria Neira, director of the WHO Department of Environment, Climate Change and Health, underlined the link between the fight against climate change and pollution of the air.

"WHO is preparing a very large report to be presented at COP26 stressing the importance of doing more to mitigate the causes of climate change as this will have huge health effects by reducing air pollution levels "she told reporters.

In children, air pollution could hinder lung development, cause respiratory infections and worsen asthma.

In adults, ischemic heart disease and stroke are the most common causes of premature death from outdoor air pollution.

- 90% of the population concerned -

New data, says the WHO, shows that outdoor air pollution can also be the cause of diabetes and neurodegenerative diseases.

In terms of disease burden, air pollution is therefore comparable according to the WHO to other important risk factors for health, such as unhealthy diet and smoking.

However, in 2019, more than 90% of the world's population lived in regions where concentrations exceeded the reference thresholds set by the WHO in 2005 for prolonged exposure to fine particles PM2.5 (diameter is less than 2 , 5 micrometers).

WHO has also halved their reference threshold.

In 2019, the annual population-weighted PM2.5 concentrations were highest in the Southeast Asia region and the Eastern Mediterranean region.

These particles can penetrate deep into the lungs (just like PM10), but also into the bloodstream.

Fine particles mainly come from the combustion of fuel in various sectors, including transport, energy and industry and agriculture.

© 2021 AFP