New Global Air Quality Guidelines aim to save millions of lives from air pollution

Cape Town | With air pollution being one of the biggest environmental threats to human health, alongside climate change, the World Health Organization (WHO) has released guidelines which aim to save millions of lives from air pollution – the Global Air Quality Guidelines (AQGs) Report was launched yesterday through a virtual press conference.

The Report comes a few weeks since the celebration of International Day of Clean Air for Blue Skies – a day to encourage efforts to improve air quality to protect human health. This year's theme: “Healthy Air, Healthy Planet” aimed to emphasize the health effects of air pollution, particularly during the COVID-19 pandemic.

These WHO Guidelines, which are evidence-based, provide a much clearer picture of the damage air pollution inflicts on human health, at even lower concentrations than previously understood while also recommending 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.

Since the last global update in 2005, there has been a marked increase of evidence that shows how air pollution affects different aspects of health. For that reason, and after a systematic review of the accumulated evidence, WHO has adjusted almost all the AQGs levels downwards, 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.

According to WHO, every year, exposure to air pollution is estimated to cause 7 million premature deaths and result in the loss of millions more healthy years of life. In children, this could include reduced lung growth and function, respiratory infections, and aggravated asthma. In adults, ischaemic heart disease and stroke are the most common causes of premature death attributable to outdoor air pollution, and evidence is also emerging of other effects such as diabetes and neurodegenerative conditions. This puts the burden of disease attributable to air pollution on par with other major global health risks such as unhealthy diet and tobacco smoking. “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,” the Report emphasizes.

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

 PM is primarily generated by fuel combustion in different sectors, including transport, energy, households, industry, and from agriculture. In 2013, outdoor air pollution and particulate matter were classified as carcinogenic by WHO’s International Agency for Research on Cancer (IARC).

The WHO 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. They are applicable to both outdoor and indoor environments globally and cover all settings.

Dr. Caradee Wright, a Senior Specialist Scientist from the South African Medical Research Council (SAMRC)’s Environment and Health Research Unit and the only South African who was an elected member of WHO’s Guideline Development Group (GDG), said the guidelines can be used to help inform a country’s national standards. She added that to that effect, the National Department of Forestry, Fisheries and Environment has recently called for a panel to review the current South African National Ambient Air Quality Standards.

“No doubt, the panel will consider WHO’s Global Air Quality Guidelines in their deliberations and consider air pollution management and interventions that will assist South Africa to best manage air quality and ensure health and wellbeing for South Africans,” said Dr Wright who participated in multiple meetings of the GDG from 2016 to 2021 and who led the first draft of the dissemination section of the new WHO Global Air Quality Guidelines Report.

On whether there is a link between air quality and the COVID-19 pandemic, Dr. Wright says air pollution is most likely a contributing factor to the health burden caused by COVID-19, citing that poor air quality is an important risk factor for both acute and chronic respiratory and cardiovascular diseases and people who have these underlying medical conditions are thought to be at a greater risk of developing severe impacts from COVID-19 infection.

The Report also highlights that during this global COVID-19 pandemic, however, there has been an important, albeit short-term, reduction of air pollution across some cities. This reduction was more prominent in the case of nitrogen oxides (NOₓ), a pollutant very much related to traffic, which was dramatically curtailed by lockdown measures. “COVID-19 has been a tragedy and still continues to be one, but at the same time, the response measures have shown us how policies related to transport, and the way people work, study and consume, can contribute to a better air quality, something that should be taken into consideration for the post-pandemic recovery policies that many countries are already working on.”

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


More about the Global Air Quality Guidelines (AQGs)
Whilst not legally-binding, like all WHO guidelines, AQGs are an evidence-informed tool for policymakers to guide legislation and policies, to reduce levels of air pollutants and decrease the burden of disease that results from exposure to air pollution worldwide. Their development has adhered to a rigorously defined methodology, implemented by a guideline development group. It was 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.

Release date: 
Thursday, September 23, 2021 - 10:20
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