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Poor air quality is considered by the Government to be “the largest environmental risk to public health in the UK”. As well as human health, air pollution also has implications for the natural environment and for the economy. Due to the transboundary nature of air pollution, action to manage and improve air quality in the UK has been driven by both international agreements and EU legislation, as well as national and devolved legislation.

This paper gives an overview of the current air quality legal framework, the changing governance and enforcement mechanisms following Brexit, forthcoming legislative changes and ongoing issues and concerns.

Current law and policy

Following the UK’s departure from the EU and the end of the transition period, those air quality laws (as set out below) originating from EU legislation have been retained in domestic legislation in accordance with the EU (Withdrawal) Act 2018 (as amended) and subsequent regulations.

At international level, the Gothenburg Protocol and amendments to it set emissions ceilings levels for various pollutants.  Its aim is to control long-range transboundary pollution. It is implemented at EU level through several directives, including the National Emission Ceilings Directives of 2001 and 2016. The 2001 Directive is implemented in the UK through the by the National Emission Ceilings Regulations 2002. The 2016 Directive sets emission ceilings which apply from 2020 and has been implemented by the National Emission Ceilings Regulations 2018.

There is also legislation relating to ambient air quality (the air that more immediately surrounds us) at EU level through Directive 2008/50/EC (the “Air Quality Directive”). Instead of setting a ceiling for pollutants, it sets “limit values” (parameters that must not be exceeded) for concentrations of different pollutants.

The Air Quality Directive is implemented in the UK through:

WHO guidelines

The World Health Organization (WHO) published updated Global Air Quality Guidelines in September 2021 covering Particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide. They provide guidance on thresholds and limits for key air pollutants that pose health risks. They are guidelines only and are not binding on any country unless that country chooses to adopt them into its own legislation. These guidelines are an update on the previous 2005 version,  Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide (PDF), which have been frequently referenced in debates about air quality targets.

UK air quality plans and policies

In the UK, responsibility for meeting air quality limit values is devolved to the devolved administrations in Scotland, Wales and Northern Ireland.  The Secretary of State for Environment, Food and Rural Affairs has responsibility for meeting the limit values in England and the Department for Environment, Food and Rural Affairs (Defra) co-ordinates assessment and air quality plans for the UK as a whole.

At a national level, the UK Government and the devolved administrations (except Northern Ireland) are required under the Environment Act 1995 to produce a national air quality strategy. The requirement for Northern Ireland stems from the Environment (Northern Ireland) Order 2002. The purpose is to have a document with common aims covering all parts of the UK. This was last reviewed and published in 2007, as the UK Air Quality Strategy for England, Scotland, Wales and Northern Ireland.

The UK Government, alongside the Scottish Government, Welsh Government and the Northern Ireland Department for Agriculture, Environment and Rural Affairs (DAERA), also published a National Air Pollution Control Programme (NAPCP) in April 2019 to meet requirements set by the revised 2016 National Emission Ceilings Directive (2016/2284). A consultation on a revised draft NAPCP was published in July 2022, which includes updated emissions projections, policies and proposed measures. 

Each government within the UK can also choose to publish its own air quality strategy. See in particular:

EU infringement proceedings

Enforcement mechanisms for failure to meet air quality limit values were previously enforced by EU institutions.

In February 2014 the EU Commission began infringement proceedings against the UK (as well as other countries) for its failure to meet air quality targets for nitrogen dioxide set by the EU Air Quality Directive in certain parts of the UK. In May 2018 the European Commission referred the UK to the Court of Justice of the EU (CJEU) for “for failure to respect limit values for nitrogen dioxide (NO2), and for failing to take appropriate measures to keep exceedance periods as short as possible.”

On 4 March 2021, the CJEU issued its decision on this case. The CJEU court had continued to oversee the case because proceedings started before the UK’s EU exit. The CJEU found that the UK had failed to fulfil its obligations under the provisions of EU Directive 2008/50/EC and that it had failed to ensure that the period of exceedance of limit values was kept as short as possible. Media reports on the case suggested that there was some uncertainty about what would happen if the UK still failed to comply within a “reasonable” period, questioning whether the UK could be forced to pay a fine.

Judicial review and air quality plan compatibility with EU legislation

Separate to the Commission proceedings, but arising from the same EU Air Quality Directive, private judicial reviews have also been brought against the UK Government stemming from the admitted and continuing failure of the United Kingdom, since 2010, to comply (in certain zones), with the limits for nitrogen dioxide levels.  These proceedings have resulted in the Government being required to produce a number of different air quality plans aimed at reducing nitrogen dioxide levels.

Future enforcement bodies

As a result of leaving the EU, environmental law and policy (including on air quality), which was derived from the EU, is no longer subject to the oversight of EU institutions, including the Court of Justice of the European Union (CJEU). Environmental campaigners raised concerns following the Brexit referendum that this would leave a “governance gap”.  As environmental matters are generally devolved, each Government within the UK has now put forward proposals to establish new environmental governance bodies to fill the role played by the EU institutions:

Recent and forthcoming legislative changes

The UK Government’s Environment Act 2021 requires the Government to set legally binding environmental targets for England in four priority areas including air quality, as well as an additional target on fine particulate matter (PM2.5), as this is considered to be the air pollutant of greatest harm to human health. In March 2022 the Government published a consultation on what the targets should look like. Both of the proposed air quality targets relate to PM2.5 and are:

  • An annual mean concentration target – a target of 10 micrograms per cubic metre (µg m3) to be met across England by 2040.
  • A population exposure reduction target – a 35% reduction in population exposure by 2040 (compared to a base year of 2018).

Provisions in Part 4 of the Environment Act 2021 deal with air quality and, from 1 May 2022, have amended the Local Air Quality Management Frameworks requirements. It also provides local authorities with greater powers in smoke control areas and includes provision to require the recall of motor vehicles on environmental grounds.

The Welsh Government has published a White Paper on a Clean Air (Wales) Bill, presenting proposals before drafting legislation. Key proposals for this legislation include a requirement for a Clean Air Plan or Strategy to be reviewed at least every 5 years; and powers to set air quality targets, including for PM2.5. It would also make amendments to the Local Air Quality Management Regime.

Future EU air quality changes

In November 2019, the EU Commission published a Fitness Check of the Ambient Air Quality Directives. It concluded that these Directives have been only partially effective in improving air quality and not all their objectives have been met. It therefore intends to revise the Directive, to align air quality standards more closely with the recommendations of the World Health Organization, subject to future consultation. An Inception Impact Assessment outlines the approach towards Commission adoption, planned for the second half of 2022. Further information is available on the European Commission webpage, Revision of the Ambient Air Quality Directives.

Health concerns

Air quality has long been a high-profile issue, with specific concerns around human health. Academic research has found big differences in air pollution across communities, with deprived areas often the worst affected. Children, the elderly and individuals with pre-existing cardio and respiratory conditions are particularly vulnerable to the effects of poor air quality. In 2020 a coroner found that air pollution was a significant contributory factor to the death of 9-year-old child.

The Covid-19 pandemic has raised questions about whether there is a link between poor air quality and Covid-19 outcomes. Researchers are also beginning to examine the effect of lockdown measures on air quality and work out what any findings mean for future policy.


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