WHO releases new, stricter, Air Quality Guidelines to save lives

The World Health Organization (WHO) released updated Air Quality Guidelines (AQGs) today that aim to save millions of lives from air pollution. The new guidelines are based on a marked increase in scientific evidence that show air pollution damages human health at even lower concentrations than previously thought.

The WHO last released updated Air Quality Guidelines in 2005. After a systematic review of the accumulated evidence since then, almost all the pollutant levels have been adjusted downward with the WHO warning that exceeding the new air quality guideline levels is associated with significant risks to health. At the same time, however, adhering to them could save millions of lives.

Air pollution is the single biggest global environmental threat to human health, alongside climate change. Every year ambient and household air pollution causes approximately 7 million premature deaths and the loss of millions more healthy years of life.  

“Air pollution is a threat to health in all countries, but it hits people in low- and middle-income countries the hardest,” said WHO Director-General, Dr Tedros Adhanom Ghebreyesus. “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.”

WHO’s new guidelines recommend air quality levels for 6 pollutants, where evidence has advanced the most on health effects from exposure (see Table 0.1). When action is taken on these so-called classical pollutants – particulate matter (PM_2.5 and PM₁₀), ozone (O₃), nitrogen dioxide (NO₂) sulfur dioxide (SO₂) and carbon monoxide (CO), it also has an impact on other damaging pollutants.

As with the WHO’s earlier guidelines, the update includes interim target levels for all six pollutants. The interim targets serve as incremental steps towards ultimately achieving air quality guideline levels, rather than as end targets.

“Annually, WHO estimates that millions of deaths are caused by the effects of air pollution, mainly from noncommunicable diseases. Clean air should be a fundamental human right and a necessary condition for healthy and productive societies. However, despite some improvements in air quality over the past three decades, millions of people continue to die prematurely, often affecting the most vulnerable and marginalized populations,” said WHO Regional Director for Europe, Dr Hans Henri P. Kluge. “We know the magnitude of the problem and we know how to solve it. These updated guidelines give policy-makers solid evidence and the necessary tool to tackle this long-term health burden.”

At the release of the new AQGs the WHO noted that some air pollutants – particularly black carbon (a component of PM) and tropospheric (ground-level) ozone – are also short-lived climate pollutants, which are linked with both health effects and near-term warming of the planet. They persist in the atmosphere for as little as a few days or months and their reduction has co-benefits not just for health but also for the climate.  

Almost all efforts to improve air quality can enhance climate change mitigation, and climate change mitigation efforts can, in turn, improve air quality. Notably, reduction or phase-out of fossil and biomass fuel combustion will reduce greenhouse gas emissions as well as health relevant air pollutants. By striving to achieve these guideline levels, countries will be both protecting health and mitigating the global climate crisis. By promoting environmental sustainability hand in hand with public health protection, large steps can be made towards mitigating climate change and achieving the Sustainable Development Goals.

“The Climate and Clean Air Coalition welcomes the new guidelines and looks forward to helping countries work toward developing integrated national climate and clean air strategies through our National Planning Initiative, and our numerous sectoral initiatives,” said Martina Otto, Acting Head of the Climate and Clean Air Coalition (CCAC) Secretariat. “There are ready-to-go solutions that can help governments take steps to meet WHO’s interim targets. We must act now for the health of people and the planet.”

Air pollution knows no borders. Increased local, national, regional and international cooperation is needed to meet the new AQGs. The CCAC is helping identify areas for action through regional assessments. For example, the CCAC’s 2019 report, Air Pollution in Asia and the Pacific: Science-based solutions, identified 25 Clean Air Measures, which if fully applied in the Asia Pacific region, would bring fine particulate matter (PM_2.5) exposure in the region down to approximately 20 micrograms per cubic meter (µg/m3) by 2030. This figure is still above the 2005 and 2021 WHO guideline levels but can increases the number of people enjoying air quality at or below 10 µg/m3 from 8 per cent in 2015, to 22 per cent by 2030 (approximately 1 billion people). A new Regional Assessment for Africa that links air pollution with climate and development goals is being completed. It will be released in early 2022. 

Dr Maria Neira, Director of the Public Health, Environment and Social Determinants of Health Department at WHO, said that because air pollution sources are different depending on location a holistic approach is needed. Governments must take steps like assessing the main sources of air pollution and then acting to reduce emissions from the responsible sectors. This will, she said, “require legislation, political will, and very big investments”.

Dr Neira said individuals should be aware of the impact air pollution has on their health and to put political pressure on leaders to act. People can also take steps to change their lifestyles in a positive way.

“The guidelines are for everyone,” Dr. Neira said.

The CCAC is working to raise awareness on air pollution in cities, regions, and countries, through the BreatheLife Campaign, a CCAC initiative led by the WHO, UN Environment Programme, and the World Bank. BreatheLife is a growing network of best practice among local governments working together to improve air quality.