For the first time in 15 years, WHO has raised air quality limits: what it means and how it impacts the environment

The World Health Organization (WHO) tightened air pollution limits, one of the greatest threats to the health of humanity and which causes seven million premature deaths each year, especially in countries with fewer resources.

The update of these criteria, published on Wednesday, is the first since 2005 and is aimed at the world’s biggest polluters. The new rules are not mandatory.

The measure aims to ensure that developed countries respect these limits in order to “protect the environment, reduce suffering and save lives,” the organization’s chief executive told a press conference. Tedros Adhanom Ghebreyesus.

The official said new data showed “how air pollution affects all parts of the body, from the brain to the growing baby in the womb, and at even lower concentrations than seen before.”

“There is nothing more essential to life than air. And yet, because of air pollution, the simple act of breathing kills 7 million per year, ”he warned.

WHO has lowered the tolerated limits for pollutants considered classicsuch as particulate matter, ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide.

The new rules are not mandatory but they give countries a framework to better protect its population.

What are the new parameters of the WHO

“We have seen over the years, with the accumulated evidence, that damage to health exists even at lower exposure levels than we thought 15 years ago, for this reason we have lowered them drastically”, said the director of the Ministry of the Environment. , WHO Climate Change and Health, Spanish María Neira.

This is the case for suspended particles with a diameter of less than 2.5 microns (PM 2.5), considered the most dangerous pollutant for humans: until now the WHO recommended less than 25 micrograms per cubic meter of air per day, while now the level drops to less than 15 micrograms.

To put it in perspective, the city of Beijing, one of the most polluted in the world, frequently wakes up to levels above 500 micrograms per cubic meter, and on exceptionally bad smog days, it exceeds 1,000 micrograms. EFE.

For slightly larger particles, up to 10 microns in diameter (PM 10), the WHO lowers its recommended daily level from 50 micrograms to 45 per cubic meter of air.

The two types of microparticles, PM 2.5 and PM 10, generally come from the combustion of fossil fuels and are particularly dangerous to health because they can enter the lungs, although the former are the most harmful, because given their small size they can reach the bloodstream according to the WHO warning.

The entity also lowered the recommended level of nitrogen dioxide (from 40 to 10 micrograms per cubic meter, annual daily average), and also suggested keeping the concentration of carbon monoxide in a day below 4 micrograms. . In 2005, he had not established any parameters for this substance.

The new guide maintained the ozone concentration recommended in 2005 (100 micrograms maximum over an eight hour period) and the tolerable amount of sulfur dioxide increased (from 20 to 40 micrograms per day), even though it is one of the main substances causing acid rain.

The recommendations aim to reduce the serious effects of all these substances on our health, since, according to Neira, 80% of deaths caused mainly by PM 2.5 particles, between five and six million, could be avoided if these parameters are respected.