“Diverse geographical, social and environmental considerations across the UK devolved nations and regions yield different air quality challenges which necessitate targeted yet coordinated policy solutions”

The quality of air we breathe in the UK has improved over the last half century – but how much further do we need to reduce pollution levels to protect human health? Much further than current legislative limits according to updated World Health Organisation (WHO) Global Air Quality Guidelines, which reflect advances in the evidence of health harms even at low exposure levels.

The new ambitious guidance has profound implications for delivery of the 2019 UK Clean Air Strategy. Air quality governance is a devolved responsibility in the UK, with administrations in Wales, Scotland and Northern Ireland responsible for setting legally binding targets and shaping contextually relevant policies.

Here we are going to explore the national and regional relevance of the new ambitious targets with the four recently appointed UK Regional Clean Air Champions: Paul Lewis (Wales), Heather Price (Scotland), Neil Rowland (Northern Ireland) and Suzanne Bartington (Midlands to the North of England).


Woodside Terrace, on a fairly rural stretch of road in South Wales with just twenty-three houses, gained notoriety in 2016 when it became known as the most ‘polluted place in Britain’ outside London with illegal levels of Nitrogen Dioxide (NO2) caused by traffic congestion. Following an agreement in the High Court with Clientearth, the Welsh Government committed to delivering a Clean Air Plan which was published in 2020.

Then, in January 2021 the Welsh Government took a further significant step forward towards a new Clean Air Act by publishing the White Paper on a Clean Air (Wales) Bill consultation. With plans well underway to ensure compliance with NO2 limit values across Wales, there was a much greater focus in the Bill on fine Particulate Matter (PM2.5), mindful of the previous WHO Global Air Quality 2005 guidelines. Perhaps very few envisaged that the new WHO annual average guideline for NO2 would be as low as 10 micrograms per cubic metre (μg/m3) which will no doubt keep this pollutant in the spotlight.

Wales will be seen by the public to have many more areas locally with unacceptable levels of NO2 regardless of whether the guidelines get adopted in future legislation. WHO’s proposed mean level of 25 μg/m3 for NO2 over a 24-hour period should also shift focus to the impacts of shorter-term exposure on health. The voices for reducing road traffic are likely to become much louder where national and local government in Wales will have an even greater responsibility to further develop existing transport strategies and engage with the public to think more about how we travel and what lifestyle changes we can make to help reduce NO2 locally.


Emissions of key air pollutants including PM2.5, nitrogen oxides (NOx) and sulphur dioxide (SO2) have reduced significantly in Scotland over recent years. Despite this, Scotland still has 36 current Air Quality Management Areas (AQMAs) in place due to excessive levels of PM10, NO2 and/ or SO2. A variety of approaches to reduce air pollution concentrations in these AQMAs are being used, including low emission zones, roadside emissions testing, workplace travel plans and promoting cycling and walking. However, similar to the rest of the UK, relatively few AQMAs have been revoked to date.

In July 2021 the Scottish Government published its new air quality strategy ‘Clean Air for Scotland 2 – Towards a Better Place for Everyone (CAFS2)’, which outlines actions to be taken over the next five years to improve Scottish air quality. The Scottish Government set out a series of priority areas for action, including tackling emissions from transport, non-transport and industry, better integrating air quality policy with other relevant policies (for example climate change and noise) and public engagement and behaviour change. Actions planned within CAFS2 should deliver tangible benefits for Scottish people in relation to air quality. However, a longer-term plan (post-five years) will be needed to move towards achieving the sorts of air pollution reductions needed to meet the ambitious new targets in Scotland.

Northern Ireland

Northern Ireland has traditionally been considered a region of the UK with low levels of air pollution. However, in addition to facing many of the same problems as other regions – high levels of NO2 in urban centres, for example – it also has unique air quality challenges. One such challenge is how to reduce relatively high ammonia emissions from its large agricultural sector, increasingly important as Northern Ireland seeks to grow its agri-food economy. Another is how to reduce emissions from households which, compared with the rest of the UK, rely heavily on solid-fuel burning and oil-fired central heating. The need to tackle both issues (alongside other air quality challenges) is ever-more pressing as the UN Climate Change Conference convenes in the Autumn to tackle the looming threat of Climate Change and as the WHO revises down its recommended Air Quality Guideline Levels to reflect the growing understanding of the public health damage caused by air pollution even at low levels. The WHO’s new guidelines make Northern Ireland’s first ever Clean Air Strategy – which in 2020 opened for discussion a series of policies for improving local air quality – even more timely and important.

Midlands and Northern England

The devolution of city region powers over spatial planning, regional transport and economic development in the major city regions – Greater Manchester, the West Midlands, Liverpool, Tees Valley and more recently Sheffield, North of Tyne and West Yorkshire – provides a major opportunity for integrated regional policies which will be essential for progress towards health-based air quality targets. As the first major city outside London to introduce a charging Clean Air Zone (CAZ), Birmingham’s experience could be used to inform future CAZ schemes, such as those proposed for Manchester and Sheffield.

Early findings suggest modest reductions in traffic and NO2 emissions within the CAZ area in the city, however far more radical policies will be necessary to make gains towards the recommended 10 µg/m3 annual average NO2 target value. Compliance based approaches, such as CAZs, are also unlikely to adequately address the environmental health burden experienced by people living in socio-economically deprived areas, such as the outskirts of post-industrial cities. The Environment Bill progressing through UK Parliament in autumn 2021, includes a duty to introduce a new legally binding PM2.5 target and population exposure reduction approach; both of which will be essential to deliver major public health gains in densely populated city regions.

Looking towards the future

Diverse geographical, social and environmental considerations across the UK devolved nations and regions yield different air quality challenges which necessitate targeted yet coordinated policy solutions. For the UK to achieve the 2021 WHO Global Air Quality Guidelines, a continuation of the gradual air quality improvements we’ve seen over the last half a century will not be enough. Instead, there needs to be transformative action across key sectors in society including industry, energy, transport and agriculture. Crucially, co-operation between regions and countries will be vital to accelerate progress towards meeting these ambitious targets.

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