Research and analysis

Lead compliance assessment 2025

Published 9 October 2026

This compliance assessment is part of Air pollution in the UK 2025. There is a page for each of 12 pollutants.

This page provides the UK’s compliance assessment for 2025 against the limit value set for lead for the protection of health.

The compliance criteria is set in the Air Quality Standards Regulations (2010).

The Air Quality Standards Regulations (2010) require reporting of compliance on an annual basis. This report continues the series of annual compliance reporting.

1. Lead pollution and its impacts

Lead (Pb) is a metallic element. Historically, lead was used as an additive in petrol, and road vehicles were the main source of airborne lead. Leaded petrol was phased out in 1999, resulting in a significant reduction to date compared with pre-1999 UK emissions.

Long-term inhalation exposure to lead can impair red blood cell formation and adversely affect the kidneys, nervous system, brain, cardiovascular system and male and female reproductive systems. Unborn children and young children are particularly sensitive to lead toxicity. Cigarette smoke is a significant source of exposure to lead in smokers.

In the environment, lead can pollute soil and surface waters and can remain there for many years after the pollution event. Exposure to contaminated soil and water may then become a health risk. Lead may accumulate in other organisms such as fish and be passed up the food chain.

2. Sources of lead pollution

The release of pollutants into the atmosphere is known as emissions. Annual UK emissions of lead are estimated each year in the National Atmospheric Emissions Inventory (NAEI). The NAEI provides estimates of the total amount emitted during a calendar year. The latest estimates currently available are for 2024.

The NAEI reports emissions of lead from human activities in the UK, but there are a few exceptions included as memo items, such as international shipping and aviation. The information presented here does not include memo items.

Figure 1 shows the split of emissions in 2024 between various sources. Road transport was the largest single contributor of lead emissions in 2024. Total UK emissions of lead have reduced significantly between 1990 and 2024.

Figure 1: UK annual emissions of lead by 2024 major emission source: 1990, 2005, 2023 and 2024

  

Notes:

1. ‘Industrial processes and product use’ refers to specific industrial production processes. This also includes the use of manufactured products, such as the use of solvents, adhesives and lubricants.
2. ‘Industrial combustion’ refers to the burning of fuels on manufacturing and construction sites, to generate energy for industrial use, for example to drive mobile machinery or to create heat or electricity for industrial processes.
3. Sources are ordered by emissions in 2024 from highest to lowest, excluding ‘Other’.
4. Further detail on emission source categories is available in the latest Methods for NAEI emissions data document.

3. Trends in lead pollution

How lead concentrations have changed over time since 1990 is shown in Figure 2. Average measured lead concentrations have decreased from an annual mean of 474.2 ng/m3 in 1990, to 5.6 ng/m3 in 2025.

The average concentration has been calculated from all stations in the Heavy Metals Monitoring Network that had an annual data capture greater than or equal to 75 per cent. The shaded areas represent the 90 per cent confidence interval. The intervals narrow over time because of an increase in the number of monitoring stations and a reduction in the variation between annual means at monitoring stations.

Trends over time can be influenced by changes to the number of monitoring sites and their locations. The pattern shown here will therefore exhibit some effect of changes to the structure of the monitoring network over time.

Figure 2: Annual mean concentrations of lead in the UK, 1990 to 2025

4. Spatial variation

Figure 3 shows modelled annual mean lead concentrations for 2025 for each 1x1km grid square of the UK. The data comes from the CMAQ-Urban model used for supplementary assessment against the limit value set for lead, as set out in section 6.

As lead concentrations are now so low across the UK, Figure 3 presents concentrations in ng/m3. The limit value for concentrations of lead is 0.5 µg/m3, which is equivalent to 500 ng/m3. All modelled grid squares across the UK were well below the limit value in 2025, but there tends to be higher concentrations in urban areas.

Figure 3: Modelled annual mean lead concentrations for 2025

Note that Figure 3 shows the modelled annual average background concentration of lead in each 1x1km grid square of the UK. Within the grid squares, there may be local areas of higher concentration close to specific emission sources. These will not be visible in the background maps.

5. Lead limit value

This section outlines the limit value set for lead concentrations.

Compliance against the lead limit value is assessed within each zone of the UK; for further information on the definition of agglomeration and non-agglomeration zones see the methods for 2025 Air Quality Standards Regulations (2010) compliance assessment.

Table 1: Lead (Pb) compliance criteria

Description	Averaging period	Metric
Pb limit value for health	Annual mean	0.5 µg/m3

The rules for assessing compliance are set out in the Air Quality Standards Regulations (2010).

6. Evidence used for assessing compliance

See the methods for 2025 Air Quality Standards Regulations (2010) compliance assessment.

The evidence base for the annual assessment of compliance against the Air Quality Standards Regulations (2010) is underpinned by a combination of measurements and the results of modelling assessments. The use of models enables air quality to be assessed at locations without monitoring sites. It has the added benefit of providing additional information on source apportionment and projections to support the development and implementation of air quality policies.

For further information on the measurements and the models used in the 2025 compliance assessment, and to download the data, see the air quality compliance assessment 2025: results and data tables.

Monitoring

In 2025, there were 19 monitoring stations from Heavy Metals Network which met the data quality requirements for assessment against the lead limit value. This includes:

• 7 background stations
• one roadside monitoring station
• 5 industrial monitoring stations
• 6 rural background monitoring stations

Further information on the monitoring instruments used for measuring lead are detailed in the air quality compliance assessment 2025: results and data tables.

Modelling

The CMAQ-Urban Model was used for compliance assessment in 2025.

For assessment against the lead limit value, one model output was calculated: annual mean concentration (µg/m3) for each 1x1km grid square of the UK.

For more information on the modelling methods and for access to the data, see the air quality compliance assessment 2025: modelled data and reports.

Modelled data is also made available in accessible formats within the air quality compliance assessment 2025: results and data tables. 

7. Compliance assessment for 2025

All zones were compliant with the limit value for lead concentrations in 2025.

The results of the assessment are also made available within the Air quality compliance assessment 2025: results and data tables.

8. Changes in compliance over time

This section provides information on non-compliances in previous years from 2008 onwards. 2008 is the year that limit values for pollutants were set in the EU Air Quality Directive, which was subsequently transposed into UK legislation by the Air Quality Standards Regulations (2010).

The UK has been compliant with the limit value for lead since 2008.