Clean Air Day is the UK’s largest air pollution campaign, created to raise public awareness of the problem of air pollution, and encourage behaviour and policy to reduce it.

4 reasons why we need Clean Air Day

By Megan Bennett, Product Marketing Manager, Nuaire

20th June 2024 will see the seventh Clean Air Day in the UK.  Clean Air Day is the UK’s largest air pollution campaign, created to raise public awareness of the problem of air pollution, and encourage behaviour and policy to reduce it.

The World Health Organization (WHO) estimates that every year, exposure to air pollution causes 7 million premature deaths and results in the loss of millions more healthy years of life world-wide.  This puts the burden of disease attributable to air pollution on a par with other major global health risks such as unhealthy diet and smoking.  It states: “Air pollution is one of the biggest environmental threats to human health, alongside climate change.”

However, it’s the low- and middle-income countries that are most at risk from high levels of air pollution.  In the UK, there has been long-term improvement in air pollution, notably PM10 and PM2.5 particulate matter (although there has been little improvement between 2015 and 2023), and nitrogen dioxide (NO2).

So, what’s the problem?  Do we really have an air pollution problem?  And is there a need for Clean Air Day?

Well, just because air pollution figures have been on a long term downward protectory does not mean all is well.  Here are four reasons why Clean Air Day has never been more important.

  1. Our air is polluted

In the UK, air quality laws are based on a combination of international commitments, retained EU law and domestic legislation.  Under these, annual average concentrations of NO2 – one of the most harmful pollutants – cannot exceed 40 µg/m3 (micrograms per cubic metre of air).  When it comes to concentrations of PM, there is a maximum annual average legal limit of 40 µg/m3 for PM10 and 20 µg/m3 for PM2.5.

In the most recent annual air quality assessment (for 2022), the UK was non-compliant with the annual mean concentration limit value for NO2 at a number of roadside locations in urban areas.

This is particularly concerning when you then consider WHO’s Global Air Quality Guidelines, which were revised in 2021 based on latest evidence on health effects from exposure to air pollution.  The WHO recommended guideline for annual average NO2 pollution is 10 µg/m – four times lower than the UK’s limit.  For PM2.5, it’s 5 µg/m3 – not the 20 µg/m set in the UK.

  1. Air pollution impacts health

So, air pollution may be on a downward trend, but it’s not coming down fast enough, especially now that we have begun to understand the true impact to our health.

The WHO warns: “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.”

The obvious risk to health is respiratory based, which has the greatest impact in the young, old and those with existing respiratory conditions, including asthma.  But it goes much further than that.  Air pollution can harm every organ, can shorten our lives, and contribute towards chronic illness. When we breathe polluted air, it can inflame the lining of our lungs and move into our bloodstream ending up in the heart and brain, causing lung disease, heart disease, dementia and strokes.  In children, for example, air pollution affects neurodevelopment, leading to lower cognitive test outcomes, negatively affecting mental and motor development.

  1. We don’t know what we don’t know

Unlike the infamous smog seen in the 1950s, air pollution is largely invisible to the naked eye.  Not being able to see something doesn’t mean it’s not there.  That’s why Clean Air Day and all the work that goes on by campaigners throughout the year is vital to raise public awareness of air pollution and its dangers.

The Clean Air Day 2021 Celebration and Insights Report found that an incredible 82% of people believe tackling air pollution should be a priority for the UK; that’s an increase of 11% over the previous three years.  The 2023 Report states that 43% of people across the country have heard of Clean Air Day, and that figure is growing.

Putting air pollution on the news agenda means that more research is being undertaken to further increase our understanding.  This includes not just external air pollution but also indoor air quality, looking at sources of pollutants and how they interact, which is a much neglected area.

  1. Awareness drives change

Knowledge is power.  Ultimately, the aim of Clean Air Day is to introduce changes – big and small – that will reduce air pollution.

On an individual level, we could all walk the shorter journeys for which we currently use the car.  In England, one quarter of all car journeys are for less than one mile.

At a government level, we know change is possible.  NOx levels have reduced over the years thanks to tighter emission standards for road vehicles and the switch away from burning coal for power generation.  But we need a government that acknowledges and will commit to the more stringent WHO air quality guidelines and that is bold enough to implement policies to get us there.

4 reasons why we need Clean Air Day

Until then, we need Clean Air Day.

For information on Clean Air Day go to  For information on Nuaire and its ventilation solutions go to