The World Health Organisation (WHO) has introduced new air quality guidelines.
It is the first global update since 2005 and the new Air Quality Guidelines (AQGs) provide clear evidence of the damage air pollution inflicts on human health, at even lower concentrations than previously understood.
The guidelines recommend new air quality levels to protect the health of populations, by reducing levels of key air pollutants, some of which also contribute to climate change.
WHO said air pollution is one of the biggest environmental threats to human health, alongside climate change.
“Improving air quality can enhance climate change mitigation efforts, while reducing emissions will in turn improve air quality. By striving to achieve these guideline levels, countries will be both protecting health as well as mitigating global climate change,” WHO said in a statement.
WHO’s new guidelines recommend air quality levels for six pollutants, where evidence has advanced the most on health effects from exposure.
When action is taken on these so-called classical pollutants – particulate matter (PM), ozone (O₃), nitrogen dioxide (NO₂) sulfur dioxide (SO₂) and carbon monoxide (CO), it also has an impact on other damaging pollutants.
The health risks associated with particulate matter equal or smaller than 10 and 2.5 microns (µm) in diameter (PM₁₀ and PM₂.₅, respectively) are of particular public health relevance. Both PM₂.₅ and PM₁₀ are capable of penetrating deep into the lungs but PM₂.₅ can even enter the bloodstream, primarily resulting in cardiovascular and respiratory impacts, and also affecting other organs.
The guidelines also highlight good practices for the management of certain types of particulate matter (for example, black carbon/elemental carbon, ultrafine particles, particles originating from sand and dust storms) for which there is currently insufficient quantitative evidence to set air quality guideline levels.
WHO director-general, Dr Tedros Adhanom Ghebreyesus, said the guidelines are applicable to both outdoor and indoor environments globally, and cover all settings.
“Air pollution is a threat to health in all countries, but it hits people in low- and middle-income countries the hardest,” he said “WHO’s new Air Quality Guidelines are an evidence-based and practical tool for improving the quality of the air on which all life depends. I urge all countries and all those fighting to protect our environment to put them to use to reduce suffering and save lives.”
In 2019, more than 90 per cent of the global population lived in areas where concentrations exceeded the 2005 WHO air quality guideline for long term exposure to PM₂.₅.
The guidelines are based on evidence obtained from six systematic reviews that considered more than 500 papers. The development of these global AQGs was overseen by a steering group led by the WHO European Centre for Environment and Health.