National statistics

Summary

Updated 27 April 2023

National Statistics

Air quality statistics in the UK, 1987 to 2022 - Summary

Updated on 27th April 2023

1. Summary

This summary provides a selection of the key information from the full publication, ‘Air quality statistics’. This publication contains statistics which help describe the trends in concentrations of five air pollutants using a variety of metrics for the period 1987 to 2022. Data come from the Automatic Urban and Rural Network (AURN), one of the UK’s air quality monitoring networks. The latest monitoring data are available from the UK-AIR website which also contains information about monitoring networks for other UK air pollutants.

The full publication is available here: Air quality statistics in the UK.

Information on the trends in concentrations of specific pollutants are available from the following links:

Air quality statistics in the UK, 1987 to 2022 – Nitrogen dioxide

Air quality statistics in the UK, 1987 to 2022 – Particulate matter (PM10 and PM2.5)

Air quality statistics in the UK, 1987 to 2022 – Ozone

Air quality statistics in the UK, 1987 to 2022 – Days with ‘Moderate’ or higher air pollution (includes sulphur dioxide)

The data used in this publication can be found in the accompanying tables. Modelled data from Pollution Climate Mapping (PCM) which estimates concentrations across the entirety of the UK are published in the autumn and are not included in this publication.

Please email us with your feedback to help us make the publication more valuable to you: Enviro.Statistics@defra.gov.uk

2. Contact

Enquiries to: Enviro.Statistics@defra.gov.uk

Tel: 03459 33 55 77 (Defra enquiries)

Lead statistician: Ellie Martell

Production team: Alex Mouatt, Neil Ward

You can also contact us via Twitter:@DefraStats

Air Quality Statistics team,

Department for Environment, Food and Rural Affairs,

Seacole Building,

2 Marsham Street,

London

SW1P 4DF

3. Nitrogen dioxide (NO2)

• Urban background and roadside nitrogen dioxide (NO2) pollution has shown long-term improvement.

• In 2022, annual mean concentrations of NO2 decreased by 1% at urban background sites and 5% at roadside sites from 2021 levels (at both roadside and urban background sites).

• In 2022, the number of hours of ‘Moderate’ or higher NO2 pollution at roadside sites was the lowest in the time series. This continues a trend for reduction in short-term ‘Moderate’ or high NO2 pollution since 2007, mainly due to reductions in this measure at monitoring sites in London.

• In 2022, as in previous years, NO2 pollution tended to peak in the rush hours and during weekdays, particularly for roadside sites. Concentrations at roadside sites in 2022 were 28% greater during the working week compared to the weekend. This pattern of concentrations follows the daily and hourly trends in road traffic.

4. Particulate matter (PM10/PM2.5)

• Urban background and roadside particulate pollution (PM10 and PM2.5) has shown long-term improvement despite a period of relative stability between 2015 and 2022.

• In 2022 annual mean concentrations of PM2.5 at both urban background and roadside sites rose by 5%, but concentrations remain lower than pre-2020 (prior to the COVID-19 pandemic) levels.

• In 2022, annual mean concentrations of PM10 at urban background and roadside locations increased from 2021, by an average of 8% and 6% respectively, but concentrations remain lower than pre-2020 levels.

• The number of hours of ‘Moderate’ or higher levels of particulate matter (PM10/PM2.5) pollution has reduced in the long term. In 2021, the number of hours of ‘Moderate’ or higher pollution recorded was the lowest in the time series for both PM10 and PM2.5. In 2022, this increased but the mean number of hours of ‘Moderate’ or higher pollution remain lower than pre-2020 levels.

• In 2022, the highest concentrations of PM2.5 in urban areas tended to occur during the spring and winter months.

• Residential combustion of wood and coal in stoves and open fires is a large contributor to emissions of particulate matter both in the UK, and across Europe, and is a large contributor towards elevated concentrations in winter months and during the evenings.

• PM2.5 concentrations also tend to peak in spring, which can be associated with air arriving from continental Europe, composed of fine particles (PM2.5) and not coarse particles (PM2.5-10), with nitrate playing a particularly important role. This nitrate appears to be largely associated with ammonium, derived from ammonia emissions which form secondary particulates and become Fine Particulate Matter (PM2.5) in the United Kingdom.

5. Ozone (O3)

• Urban background concentrations of O3 have shown a long-term increase, partly due to reductions in other pollutants which limit ozone concentrations (for example NOx). In 2022 concentrations increased 4% from 2021 reaching 65.1 µg/m3 which is the highest value in the time series. Rural background ozone pollution has shown no clear long-term trend.

• There were on average more hours of ‘Moderate’ or higher ozone pollution in 2022 compared with 2021 at both urban and rural background sites. The number of hours of ‘Moderate’ or higher ozone pollution at both site types has been generally high since 2018, with the exception of 2021.

• Ozone pollution is linked to hot, sunny conditions and prolonged instances of such conditions during the summer in 2018, 2019, 2020 and 2022 likely contributed to the higher incidences of ‘Moderate’ or higher ozone pollution observed during these periods.

• In 2022, concentrations of ozone at both urban and rural background sites built up over the first few months of 2021, peaking in April then sharply decreasing between August and September. There was a slight increase in August, but afterwards, concentrations steadily decreased towards November, while rising slightly again towards the end of the year.

6. Days with ‘Moderate’ or higher air pollution (includes sulphur dioxide)

• There were on average 9 days of ‘Moderate’ or higher pollution at urban pollution monitoring sites in 2022, up from 4 in 2021.

• Since reaching the highest value in the time series in 2018, the number of days of ‘Moderate’ or higher air pollution at rural monitoring sites has remained comparatively high but shows no clear trend.

• Since 2015 the mean number of days of ‘Moderate’ or higher pollution has been higher at rural sites than urban sites due to ozone pollution. There were on average more days of ‘Moderate’ or higher pollution at rural pollution monitoring sites in 2022 compared with 2021 (11 days in 2021, 22 days in 2022).

• In 2022, as in previous years, ozone was responsible for a large proportion of the ‘Moderate’ or higher pollution days. An increase in ozone pollution throughout 2018, 2019, 2020 and 2022 was in part due to the prolonged hot and sunny conditions experienced in the UK in the summers of these years.

7. Sections in this release

Background to concentrations of air pollutants

Concentrations of nitrogen dioxide

Concentrations of particulate matter (PM10 and PM2.5)

Concentrations of ozone

Days with ‘Moderate’ or higher air pollution (includes sulphur dioxide)

Compliance with the Code of Practice for Statistics and Defra group Statistics quality principles, and recent changes to the publication

Statistical tables (ENV02 – Air quality statistics)