A decade of air quality: the past, present and future of clean air

Air Quality News editor Chloe Coules examines how much progress has been made on tackling air pollution in the past decade, and whether we should be optimistic about the future of our air.  

It is undeniable that significant progress has been made on air pollution in the UK since the introduction of the Clean Air Act in the 1950s. ‘All our major cities were very dirty, very grimy, and the stuff in the air contaminated all the buildings, shortened lives, and made life quality very poor. Today if you look outside, it’ll be a beautiful blue sky,’ explains Professor David Fowler CBE, UK Centre for Ecology & Hydrology fellow.  

The last decade has been an especially pivotal time for public and political awareness and action to tackle the public health issue of dirty air.  

‘Air quality, and certainly attitudes towards air quality, have changed significantly in the last decade,’ says Minister for Agri-Innovation and Climate Adaptation at DEFRA, Jo Churchill MP.  

‘Cleaning up our air is an absolute priority for me, for the department, and the wider government. We’ve made progress in the last 10 years – air pollution emissions have reduced significantly since 2010, with NO2 levels down by 44%, sulphur dioxide levels down by 70% and PM2.5 down 18%. Our Clean Air Strategy was described as an “example for the rest of the world to follow” by the World Health Organisation. But there is still more to do.’ 

Improvement in air quality in the past few decades has primarily been driven by a desire to reduce mortality from air pollution, argues Professor Fowler, but despite the air seeming much cleaner, the health impacts are still significant. ‘If you take 2020 or 2021, there are still about 30,000 people in the UK who die earlier than they should because of air quality.’ 

One of these people was nine-year-old Ella Adoo-Kissi-Debrah, who tragically died following an asthma attack in 2013. Ella and her family lived near the South Circular Road in Lewisham, and in the three years leading up to her death she had multiple seizures and was admitted to hospital 27 times.  

A ground-breaking inquest in 2020 found that air pollution contributed to Ella’s death, with the coroner Philip Barlow concluding that the young girl had been exposed to ‘excessive’ levels of air pollution, making her the first person to have air pollution recognised as a cause of death.   

Ella’s mother, Rosamund Adoo-Kissi-Debrah, fought tirelessly alongside her lawyers over the past decade to deliver this landmark ruling, but for her it is only starting to sink in. She tells Air Quality News: ‘I don’t feel like I was able to take in the enormity [of the ruling], but now I’m beginning to appreciate it a bit more and how I want to use it in a positive way.’ 

In order to address the present health impacts of air pollution, the government has proposed new legally binding air quality targets that will see levels of PM2.5 reduced to 10 micrograms per cubic metre by 2040. 

Ms Churchill tells Air Quality News: ‘Last year, we passed our world leading Environment Act, and I think that is a real game changer. We are already consulting on legally-binding targets under the Environment Act, including on air quality. In particular, I want to reiterate the action we are taking on PM2.5 – including an innovative population exposure reduction target which will focus on cutting people’s exposure to this harmful pollutant by over a third, rather than exclusively focusing on reducing the sources of air pollution. Following the tragic death of Ella Adoo-Kissi-Debrah, we have set out key actions to improve air quality in the short and long term, protect vulnerable groups and effectively communicate information to the public. 

‘I am a former health minister and I understand that air pollution is the single biggest environmental risk to public health. I want to make sure that our children and grandchildren are able to breathe clean air. I would also like to thank all of those, including Rosamund Kissi-Debrah – who have done so much to raise awareness of the issue and to those working on solutions.’ 

However, Rosamund argues that we have not made enough progress to tackle air pollution in the last decade: ‘We still have illegal levels of air pollution in 70% of the UK. The government have brought out this new consultation, which is not strong enough – the WHO targets they are talking about are the 2005 targets and they have said they will implement them by 2040, 35 years too late. In the meantime, last year the WHO came out with new guidelines.’ 

She tells Air Quality News that she believes the proposed targets are ‘an insult’ to her daughter’s memory. ‘They need to be more ambitious. They can have interim targets, but they need to bin the 2005 targets and move onto the 2021 targets because ultimately that will save lives.’ 

On one hand, Rosamund thinks it is positive that awareness of air pollution has risen in the past decade and has become a key issue for voters, but she does not think this alone is enough.  

‘In a way we have moved along but there is a lack of urgency – it is a public health crisis,’ she explains. 

Looking forward: what to expect in the next decade 

In the next decade, Professor Fowler predicts that we will continue to see a slow decline in emissions of particulate matter and a continued decrease in NO2. There is also evidence that we are past the global peak in sulphur emissions and close to the peak in NOx.  

However, as we clean up vehicle emissions and bring down NOx levels, ozone levels may increase, explains Professor Fowler. ‘Ozone will gradually become a bigger problem, and ozone has a geographical scale that is global rather than UK specific. So, policies in the UK are important to contribute to that, but the UK on its own cannot control the Northern Hemisphere background ozone, it’s only action by all countries together [that can control it], and so far, there are no international agreements like the ones we have in Europe for sulphur and nitrogen.’ 

Ozone is not the main cause of human health dangers from air pollution, but it does contribute to the health burden, and rising ozone would have concerning implications for global food supply, warns Professor Fowler: ‘It does have effects on crop productivity, and there is a worry about global supplies of food. It significantly depresses the yields of some of the major crops like wheat and soybean.’ 

While peaks of ozone have decreased in the UK and across Europe and North America in the last decade, the global background levels have been growing, so the international burden of ozone will be one of the key challenges in the next decade.  

Professor Fowler also explains that we have done very little globally to tackle ammonia levels in the last decade, making it a major concern for the future. ‘The one pollutant we seem to be making almost no progress with globally is ammonia, and ammonia is very important because it’s a large contribution to PM. It comes from agriculture and all the industrial nations with intensive agricultural industry have large ammonia emissions, and they haven’t come down. So, as we clean up everything else, you can see ammonia stands out as the thing globally that we’ve done the least about.’ 

Environment Minister Jo Churchill echoes this concern, saying: ‘The transboundary nature of air pollution is a challenge, so we will continue to work with international neighbours and support the UNECE Convention for Long-Range Transboundary Air Pollution to manage down both domestic and global emissions.’ 

In the UK, the government is optimistic that we will continue to see air quality improvements in the next decade. Ms Churchill comments: ‘Air quality has improved since 2010, and the most recent figures all suggest that we are on the right trajectory. Emissions of sulphur dioxide, nitrogen oxide, PM2.5, PM10, NMVOCs, and ammonia all decreased between 2019 and 2020. Our latest emission projections published in March 2022 showed that we expect to continue to see reductions this decade. And our new air quality targets, together with our Clean Air Strategy, will help drive down some of the most harmful pollutants even further.’ 

Current data also suggests that we may be past the global peak in air pollution – meaning that the worst may be behind us – but there is concern that reductions could be offset by increases in pollution in developing cities.  

‘It looks from the satellite remote sensing data as though maybe the peak of global pollution has taken place in the last decade, but we need a bit more data and analysis to be sure. We could be past the peak, but of course if you look at the very rapidly growing cities in Africa, you might wonder whether Africa will go through the same development cycle as Europe, East Asia and North America,’ explains Professor Fowler.  

‘If they took green approaches they could avoid these peaks in PM, but at the moment it looks as though the trends are going in a similar direction to all the other continents that have gone through this very serious evolution problem.’ 

Climate change is also a double-edged sword for air pollution. On one hand, net zero policies have vast potential to make air quality better, but some policies do not fit well with air pollution reduction and may even worsen air quality, warns Professor Fowler.  

For example, a popular policy is to plant more trees to tackle emissions, but some species can be detrimental to air quality, explains Professor Fowler: ‘If we have vast plantations of trees which emit large amounts of VOCs, we would be benefitting the climate but degrading air quality, because the VOCs would make particulate matter and they would also contribute to ozone formation.’ 

‘Overall, we must ensure that the work we are doing to achieve net zero continues to align with policies that improve air quality,’ agrees Ms Churchill.  

The Minister highlights that innovation will be key to keep making progress on air pollution in the coming years.  

‘Innovation is absolutely key to address air quality. We need to go further and faster to decarbonise transport. The Prime Minister’s 10 Point Plan for a green industrial revolution set out our intention to phase out the sale of new petrol and diesel cars and vans by 2030, having already committed £1.5 billion and pledged another £2.8 billion to support the electric vehicle market. We are also aiming for half of all journeys in towns and cities to be cycled or walked by 2030 to help lower congestion as we aim to better air quality in urban areas more widely,’ she says.  

She adds that collaboration between the different levels of government is crucial to progress: ‘To address the issues we are facing, we need national and local governments to work together to deliver change. We need to do it in a way that delivers the clean air that we all want, without creating unnecessary burdens on businesses and residents. We have worked closely with local authorities to improve air quality and continue to do so, strengthening Local Air Quality Management guidance to help maximise the benefits of local action, and awarding £42 million across 500 projects on the Air Quality Grant scheme since 2010. Going forward, my continued focus is working with local authorities and my colleagues at the Department of Health and Social Care – including the Chief Medical Officer – to review how we communicate air quality information more effectively to ensure the public, and vulnerable groups in particular, have the information they need to protect themselves.’

Rosamund echoes this, saying the government needs to invest in public transport and inform the public of the detrimental impacts of air pollution. She says she would like us to get to a stage where there air leaflets about air pollution in the waiting rooms at hospitals and GPs, and where public messaging on air pollution is of a similar level to what was seen during the Covid-19 pandemic.  

She also hopes that in the next decade clean air will become a human right: ‘I believe my daughter’s right to life was breached, and I would like that put right.’ 

Only time will tell whether all of these aims will be achieved, but it is clear that governments will be under tighter scrutiny going forward as the public wakes up to the catastrophic impacts of air pollution, and we will look back on this decade as a point of no return for clean air.  

This article first appeared in the May issue of Air Quality News – view it in full here. 

Illustrations by David Gooda