The quest for clean air

The will for political action on air pollution is not a new phenomenon. The urban smogs seen in the 1950s and 1960s were problematic enough to precipitate both vociferous public concern and Government action – leading to the first Clean Air Act in 1956.

Now, clean air experts from across the University of Birmingham are combining their expertise to champion an even greater focus on improving air quality.

On 9 November 2021, the Environment Bill, the UK’s post-Brexit law on environmental governance and regulation, received royal assent and became the Environment Act 2021. It established a legally binding requirement to bring forward at least two new air quality targets; a new long-term target for toxic fine particulate matter (PM2.5) concentrations and a target for population exposure reduction. In December 2022, these new targets were announced:

  • An Annual Mean Concentration Target for PM2.5 levels in England to be 10 µg m-3 or below by 2040.
  • A Population Exposure Reduction Target for a reduction in PM2.5 population exposure of 35% compared to 2018 to be achieved by 2040.

While these underline a renewed commitment to cleaner air, the Birmingham team are looking to continue growing the evidence base to demonstrate the severe harms caused by poor air quality and identify practical, cost-effective solutions.

Their deep examination of air quality, that cuts across traditional academic disciplines, demonstrates how insights from a range of subjects can lead to meaningful improvements to our health and the environment.

The importance of regional focus

Professor William Bloss points to the Institute for Global Innovation (IGI) at the University of Birmingham as catalysing factor for the research, providing the fora through which such networks can be developed. “The IGI accelerates the processes of convening people and identifying opportunities across departmental boundaries. It allows us to broaden our expertise quickly and rapidly adapt to wherever the project needs to go.”

He also highlights how the WM-Air initiative, of which he is Principal Investigator, uses these multidisciplinary, collaborative approaches to co-design projects across the West Midlands.

Birmingham skyline at night

WM-Air – the West Midlands Air Quality Improvement Programme - is an initiative to support the improvement of air quality, and associated health, environmental and economic benefits, in the West Midlands.

A key output from WM-Air has been development of a framework, alongside the West Midlands Combined Authority, that will support the air quality work being done by its constituent local authorities.

This meant bringing together an evidence base to inform a future air quality strategy focused on a) establishing the health impacts of poor air quality in the West Midlands, b) quantifying the impacts of air quality measures under consideration, and c) exploring air quality and climate change co-benefits related to regional net zero strategies. 

It’s an example that covers the three core strands that underpin the project – building awareness, developing predictive capability, and supporting the application of interventions.

“Regions and city actors are making much of the running on improving air quality, particularly in England,” says Professor Bloss, “and they’re increasingly driven by concerns about public and environmental health, rather than just having to comply with the legal limit.”

“Our role,” summarises Professor Bloss, “is to provide the scientific basis and know-how that helps enact change - because the benefits of these local actions in terms of human health, reduced inequality and improved lives are clear.”

Making the invisible visible

The UK has seen a marked reduction in nitrogen dioxide (NO2) levels in recent decades. NO2 pollution stems from causes that are easily observable– car exhausts, industry, the burning of fossil fuels – and the move to reduce it was perhaps aided by its clear sources.

Much less progress has been made on tackling fine particles such as PM2.5 - less than 30 times the diameter of a human hair and invisible to the naked eye.

Helping decision-makers and the public at large to understand the need for improved air quality and a reduction in the tiny pollutants is a sizeable challenge. One key factor is understanding their sources and formation processes, and that starts with being able to accurately monitor the compounds in our air.

“The high-profile haze or smog events that sparked the Clean Air Act in the 1950s are a thing of the past, at least in the UK. Even under extreme conditions it would be near impossible to see them happen again. So, we have to provide observational data on the particulates in our air and present that insight in a helpful way that illustrates the scale of the problem.” says Professor Zongbo Shi, expert in atmospheric biogeochemistry. Biogeochemistry is, in itself, interdisciplinary as it explores the physical, chemical, biological, and geological processes and reactions that govern the composition of and changes to the natural environment.

The need to collect comprehensive data was a driving force behind the NERC-funded (Natural Environment Research Council) air quality supersite triplets (UK-AQST) project, led by Professor Shi.

Existing Defra (Department for Environment Food and Rural Affairs) monitoring stations across the UK monitor the concentration (or level / abundance) of all, or some, standard criteria pollutants including PM2.5, PM10, carbon monoxide, sulphur dioxide, nitrogen dioxide, and ozone. The AQST supersites are able to monitor a broader range of compounds and in far greater detail.

“What we’re trying to do is paint a more complete picture of our air,” explains Professor Shi. “We want to know what the particles look like, how many are there in the air, how toxic they are, and where they come from. After all, if you’re trying to improve air quality you have to start with knowing what the source of pollution is.”

That greater understanding of the particles in the air is crucial for developing air quality models. Professor Shi and his colleagues are combining traditional methods of analysis with machine learning techniques to refine models in order to understand the processes that underpin air quality, help predict future trends, and quantify the likely benefit of clean air interventions such as Clean Air Zone and Net Zero policies. In doing so, they are helping to make the invisible visible.

Sounding out pollution: the WM-Air team worked with a sonic artist, Robert Jarvis, as part of an innovative, NERC-funded public engagement project which used sound to ‘hear’ air quality data. This work was presented to the public as part of ‘The Air We Breathe‘ exhibition.

The impact on human health

In his 2022 annual report, CMO (Chief Medical Officer) Professor Sir Chris Whitty acknowledged that, while outdoor air pollution in England has reduced significantly since the 1980s, it still poses significant threats to human health across the entire life course, from conception to old age.

It follows the World Health Organization updating their health-based air quality guidelines in Autumn 2021 to reflect evidence of negative health impacts occurring at concentrations well below what was previously thought – and well below the new UK air quality targets announced by Defra.

Per the CMO’s report, air pollution kills an estimated 26,000 to 38,000 people a year in England alone, mainly due to respiratory and circulatory diseases including heart disease, stroke, lung cancer and asthma. However, air pollution is rarely recognised as a contributor to early death. Nine-year-old Ella Adoo-Kissi-Debrah, who died following an asthma attack, was the first person in the world to have air pollution listed as a case of death.

Cyclist on his bike wearing face mask

The interdisciplinary research team studying Air Quality at Birmingham contributed to the development of the Chief Medical Officer’s report.

For Dr Suzanne Bartington, Clinical Research Fellow in Environmental Health in the Institute of Applied Health Research and Public Health lead at WM-Air, it represents a landmark moment for how the UK views air quality. “This feels like a watershed moment. I think people are coming to terms with the harmful nature of poor air quality but there’s still something of a misconception that it is all about lung health. In truth, the greatest harm – in terms of overall impacts - is to our cardiovascular system and we’re only scratching the surface of how much damage can be done to our brains.”

Acknowledging the scale of the impact on human health is one thing. Deciding on the best way forward is another.

In August 2022, the WM-Air team launched the Air Quality Lifecourse Assessment Tool (AQ-LAT) to support local authority professionals and practitioners in appraising and evaluating the health and economic impacts of current and future air quality scenarios in the West Midlands region. It allows for decision-makers to test different policies and interventions to determine what the likely benefits or harms may be.

“Having a tool like this helps us immensely,” continues Dr Bartington. “Whether a local authority is looking to reduce road emissions or focus their efforts on agricultural processes, we can model the likely health benefits of each action and identify how those benefits might be distributed across particular disease types, geographies and demographics.”

It is another string to the bow of the WM-Air network - a NERC funded initiative, led by the University of Birmingham, working in collaboration with over 20 cross sector partners. Collectively, the projects apply environmental science expertise to support the improvement of air quality, and associated health, environmental and economic benefits, across the West Midlands.

“The clean air research we’re doing across the University, is a really good example of the need for interdisciplinary thinking,” says Dr Bartington. “We can’t understand these problems or develop solutions without a whole systems approach. If you do something siloed or compartmentalised then you’ll end up with trade-offs or unintended consequences. You have to fully understand all the factors at play to properly predict, and implement, solutions.”