Air Quality in Cardiff: Pollution Levels, Causes and Health Impacts

Cardiff is the capital of Wales and its largest city. Its air quality is influenced by road traffic, commercial activity, construction, domestic heating, weather conditions and emissions transported from surrounding areas. Air pollution is an important environmental and public health issue because it affects respiratory health, cardiovascular health, ecosystems and the overall quality of urban life.

Cardiff has made measurable progress in reducing air pollution. Cardiff Council’s 2025 Annual Progress Report, which examines monitoring data collected during 2024, recorded nitrogen dioxide concentrations below the relevant national air quality objectives at all monitored locations. The report also identified improvements in areas that previously experienced higher pollution levels, including Castle Street. Local Air Quality Management+2

Understanding air quality in Cardiff requires examining the pollutants present in the atmosphere, their sources, the locations monitored by environmental authorities and the measures used to improve urban air quality.

What Does Air Quality Mean in Cardiff?

Air quality in Cardiff describes the condition of outdoor air and the concentration of pollutants that people breathe across the city. It is assessed by measuring substances such as nitrogen dioxide, particulate matter, ozone and sulphur dioxide against recognised environmental standards.

Air quality refers to the cleanliness of the atmosphere and the concentration of substances that affect human health and the natural environment. Clean air contains relatively low concentrations of harmful pollutants, while polluted air contains substances released through transport, industry, heating, construction and other activities.

Cardiff’s air quality is influenced by its urban structure and geographical position in South Wales. The city contains busy transport corridors, residential neighbourhoods, commercial districts, industrial premises and green spaces. These different environments produce different pollution conditions.

Roadside locations experience pollution associated with vehicle exhausts, tyre wear, brake wear and road dust. Urban background locations measure pollution across wider residential and commercial environments rather than immediately beside busy roads.

Air quality monitoring helps Cardiff Council identify pollution patterns, evaluate environmental policies and determine whether specific locations require additional intervention.

The Welsh Government also operates the Air Quality in Wales information service, which provides monitoring information and pollution updates for locations across the country. srs.wales+1

Why Is Air Quality Important for Cardiff Residents?

Air quality matters because polluted air increases the risk of respiratory and cardiovascular problems and affects people who live, work, study and travel in Cardiff. Children, older people and individuals with existing respiratory or heart conditions experience particular health risks.

Air pollution is a major environmental health concern. Exposure to harmful airborne substances affects the respiratory system and cardiovascular system. Fine particles can penetrate deep into the lungs, while certain gases irritate airways and contribute to respiratory symptoms.

Cardiff’s population experiences different levels of exposure depending on daily activities and residential surroundings. People travelling along busy roads, working near traffic corridors and spending extended periods in congested urban locations encounter different pollution conditions from those living near parks and less heavily trafficked streets.

Children are particularly important in air quality planning because their lungs are still developing. Older people and individuals with asthma, chronic obstructive pulmonary disease (COPD) or cardiovascular conditions also require consideration.

Air pollution also creates wider environmental consequences. Pollutants contribute to atmospheric chemical reactions, damage vegetation and affect ecosystems.

For Cardiff, improving air quality supports public health, sustainable transport, environmental protection and the long-term liveability of neighbourhoods.

Which Pollutants Affect Air Quality in Cardiff?

Cardiff monitors several important air pollutants, including nitrogen dioxide, particulate matter PM10, fine particulate matter PM2.5, ozone and sulphur dioxide. These substances originate from transport, fuel combustion, industrial activities and atmospheric chemical reactions.

Each pollutant has different characteristics and environmental effects. Understanding these substances helps explain why air quality varies between Cardiff neighbourhoods.

Nitrogen dioxide (NO2)

Nitrogen dioxide is a harmful gas produced mainly through high-temperature fuel combustion. Road vehicles are an important urban source, particularly diesel-powered vehicles.

Busy roads, traffic junctions and areas with frequent vehicle movement experience higher roadside concentrations. Cardiff monitors nitrogen dioxide because long-term exposure affects respiratory health and contributes to the formation of other atmospheric pollutants.

The annual mean air quality objective for nitrogen dioxide in the UK is 40 micrograms per cubic metre (µg/m³).

Particulate matter PM10

PM10 refers to airborne particles with a diameter of 10 micrometres or smaller. These particles originate from road dust, construction activities, tyre wear, brake wear and combustion.

Wind and vehicle movements redistribute particles across urban environments. PM10 affects air quality because particles enter the respiratory system when people breathe polluted air.

Fine particulate matter PM2.5

PM2.5 describes particles with a diameter of 2.5 micrometres or smaller. These particles originate from vehicle emissions, domestic heating, industrial combustion and atmospheric chemical reactions.

Fine particles penetrate deeper into the lungs than larger particles. Long-term exposure is associated with cardiovascular and respiratory diseases.

Ground-level ozone

Ground-level ozone is a secondary pollutant formed when nitrogen oxides and volatile organic compounds react in sunlight.

Unlike ozone in the upper atmosphere, ground-level ozone affects human health. Concentrations often increase during sunny weather and can cause respiratory irritation.

Sulphur dioxide (SO2)

Sulphur dioxide is a gas produced primarily through burning fuels containing sulphur. Industrial combustion and certain fuel-burning activities contribute to its emissions.

Exposure irritates the respiratory system and aggravates existing breathing conditions.

These pollutants require different monitoring methods because their sources, atmospheric behaviour and health effects vary.

What Are the Main Causes of Air Pollution in Cardiff?

Road transport is an important source of urban air pollution in Cardiff. Other contributors include domestic heating, construction dust, commercial activities, industrial emissions and pollution transported through the atmosphere from surrounding areas.

Air pollution develops through a combination of human activities and environmental processes. Cardiff’s transport network, built environment and residential heating requirements influence local pollutant concentrations.

Road traffic and vehicle emissions

Road transport is a major consideration in Cardiff’s air quality management.

Cars, buses, taxis, delivery vehicles and heavy goods vehicles release pollutants through fuel combustion. Vehicle components also produce non-exhaust particles through tyre friction, brake wear and road surface deterioration.

Traffic congestion increases the amount of time vehicles spend operating at low speeds or idling. Busy roads around Cardiff city centre and major transport corridors therefore require continued monitoring.

Domestic heating and fuel combustion

Residential heating contributes to air pollution through the combustion of fuels. Gas boilers, solid-fuel appliances and wood-burning stoves produce different quantities and types of emissions.

Smoke from domestic fires contains particulate matter and other combustion products. The effects depend on fuel quality, appliance efficiency and how the heating equipment operates.

Construction and demolition activities

Construction sites generate dust through excavation, demolition, material handling and vehicle movements.

Large development projects require dust management measures to prevent particles spreading into nearby residential and commercial areas.

Cardiff’s expanding urban environment makes construction-related pollution an important consideration for environmental planning.

Commercial and industrial activities

Commercial kitchens, industrial premises, workshops and fuel-burning equipment contribute to local emissions.

Shared Regulatory Services investigates certain air pollution complaints across Cardiff, Bridgend and the Vale of Glamorgan. Its environmental health responsibilities include dealing with pollution from commercial premises and industrial activities. srs.wales

Regional and weather-related pollution

Not all pollution measured in Cardiff originates within the city.

Air currents transport pollutants between neighbouring communities and regions. Weather conditions also influence how pollutants disperse.

Wind can dilute local emissions, while stagnant atmospheric conditions can allow pollution to accumulate. Sunlight contributes to chemical reactions that produce ground-level ozone.

These factors explain why air quality changes throughout the year and sometimes differs between locations within Cardiff.

How Has Air Quality in Cardiff Changed Over the Years?

Cardiff’s air quality has improved over recent years, particularly for nitrogen dioxide. The council’s 2025 progress report recorded a 36% reduction in nitrogen dioxide concentrations since 2019 and no exceedances across its 99 non-automatic monitoring locations in 2024.

Cardiff’s air quality management has developed through national environmental legislation, local monitoring programmes and targeted pollution reduction measures.

Historically, road traffic emissions created significant nitrogen dioxide problems along busy urban roads. Several locations exceeded or approached the annual nitrogen dioxide objective, resulting in the designation of Air Quality Management Areas.

The COVID-19 pandemic also influenced air pollution patterns. Reduced travel during lockdowns lowered traffic activity across many urban areas. Following the reopening of workplaces and businesses, traffic levels increased again.

However, Cardiff’s longer-term monitoring results demonstrate continued improvement rather than a temporary reduction associated exclusively with lockdown restrictions.

The 2025 Annual Progress Report examined monitoring results from 2024. Its findings included:

• A 36% reduction in nitrogen dioxide concentrations since 2019.
• No exceedances at 99 non-automatic nitrogen dioxide monitoring locations.
• Compliance with the annual mean nitrogen dioxide objective across all four designated AQMAs.
• A Castle Street annual mean nitrogen dioxide concentration of 30 µg/m³ in 2024, compared with previous levels exceeding 40 µg/m³.

These findings demonstrate the progress achieved through transport management, monitoring and environmental interventions.

How does Cardiff compare with wider Welsh trends?

The Welsh Government’s Air Quality in Wales 2024/25 report also identifies long-term improvements in nitrogen dioxide concentrations.

Welsh urban traffic monitoring sites recorded an average annual nitrogen dioxide concentration of 19.4 µg/m³ in 2024, compared with 33.8 µg/m³ in 2008.

Urban background monitoring sites recorded an average of 11.6 µg/m³ in 2024. This was the lowest annual mean recorded by the relevant long-running monitoring series.

These national figures provide useful context for understanding Cardiff’s progress within the wider Welsh environmental picture.

Where Are the Air Quality Management Areas in Cardiff?

Cardiff has four designated Air Quality Management Areas: Cardiff City Centre, Ely Bridge, Llandaff and Stephenson Court. These locations were identified because of historical nitrogen dioxide pollution concerns, particularly near busy roads and transport corridors.

An Air Quality Management Area (AQMA) is a geographical location designated by a local authority when air quality objectives are not being achieved or are unlikely to be achieved.

The designation requires the authority to prepare and implement measures intended to improve local air quality.

Cardiff’s four AQMAs provide an important historical and administrative framework for understanding pollution management.

Cardiff City Centre

The Cardiff City Centre AQMA includes locations around central roads and commercial districts.

Traffic movements, buses, taxis, delivery vehicles and pedestrian activity contribute to the area’s environmental conditions.

Castle Street has been an important focus of air quality improvements because of its previous nitrogen dioxide concentrations.

Ely Bridge

Ely Bridge AQMA covers residential premises along sections of the A48 Cowbridge Road West, Western Avenue and the A4119 through Llandaff Village and Cardiff Road.

Its designation reflects historical concerns about nitrogen dioxide concentrations associated with road transport.

Llandaff

Llandaff AQMA covers an area around Cardiff Road through Llandaff village.

Traffic moving through the village has historically contributed to nitrogen dioxide pollution. Monitoring remains important for assessing whether improvements are sustained.

Stephenson Court

Stephenson Court AQMA is located around Newport Road and nearby residential properties.

The area was designated in November 2010 because of nitrogen dioxide concerns associated with road transport.

The Department for Environment, Food and Rural Affairs (Defra) maintains the official national AQMA register, including Cardiff’s designation history.

Are Cardiff’s Air Quality Management Areas still necessary?

Cardiff’s 2024 monitoring results showed that all four AQMAs were below the annual mean nitrogen dioxide objective.

The council has considered whether Cardiff City Centre, Ely Bridge and Stephenson Court are suitable for revocation. Further detailed assessments are necessary before formal decisions.

Llandaff also requires continued assessment.

A reduction in pollution does not automatically remove an AQMA designation. Authorities must consider future pollution projections and establish that compliance will continue before revoking an area.

How Does Cardiff Council Monitor Air Quality?

Cardiff Council monitors air pollution through automatic monitoring stations, nitrogen dioxide diffusion tubes and additional indicative sensors. These systems measure pollutant concentrations, identify changing pollution patterns and provide evidence for annual environmental assessments.

Air quality monitoring is an essential part of local environmental management. It allows authorities to identify pollution hotspots, compare annual results and assess whether improvement measures are effective.

Cardiff’s monitoring programme operates through Shared Regulatory Services, which undertakes environmental health and pollution monitoring responsibilities on behalf of the local authority.

Automatic monitoring stations

Automatic monitoring stations continuously measure selected pollutants and provide detailed information about changing concentrations.

Cardiff’s 2024 monitoring programme included three automatic monitoring locations:

• Frederick Street.
• Richards Terrace.
• Castle Street.

These monitoring locations provide information about nitrogen dioxide and particulate matter. Automatic instruments produce measurements at regular intervals, allowing environmental authorities to examine hourly and daily variations.

Nitrogen dioxide diffusion tubes

Diffusion tubes are small sampling devices used to measure average nitrogen dioxide concentrations over a specified period.

They provide a relatively economical way to monitor numerous locations across a city.

Cardiff’s 2024 programme included 99 non-automatic monitoring locations. The results showed no exceedances of the relevant nitrogen dioxide objectives at these locations.

Diffusion tubes are particularly useful for identifying pollution patterns along roads and residential streets where permanent automatic monitoring stations are unavailable.

Indicative monitoring sensors

Indicative sensors provide additional information about local pollution conditions.

These devices help environmental authorities understand variations between monitoring locations and identify areas requiring further investigation.

However, indicative sensors and reference-grade automatic monitoring equipment do not necessarily provide measurements with identical accuracy. Authorities consider equipment performance and data quality when interpreting results.

Annual air quality reporting

Cardiff’s annual reporting process examines monitoring results, compares concentrations against environmental objectives and evaluates pollution reduction measures.

The reports are submitted to the Welsh Government for review.

Residents can also consult the official Air Quality in Wales monitoring website to examine available monitoring information and pollution updates.

What Is the Impact of Air Pollution on Human Health?

Air pollution affects respiratory and cardiovascular health through exposure to harmful gases and airborne particles. Long-term exposure increases the risk of heart disease, stroke, lung cancer and chronic respiratory conditions, particularly among vulnerable population groups.

The health effects of air pollution depend on pollutant type, concentration, exposure duration and individual health characteristics.

The World Health Organization (WHO) identifies air pollution as a major environmental health risk. Fine particulate matter is particularly concerning because small particles penetrate deep into the respiratory system and enter sensitive lung tissues.

Respiratory health

Nitrogen dioxide and particulate matter contribute to respiratory problems.

Exposure can irritate the airways and worsen symptoms among people with asthma and other breathing conditions.

Children require particular protection because their respiratory systems are still developing. Regular exposure to polluted environments also affects people who already have reduced lung function.

Cardiovascular health

Fine particulate matter is associated with cardiovascular disease.

Air pollution exposure contributes to inflammation and other biological processes that affect blood vessels and cardiovascular function.

People with existing heart conditions face increased risks from prolonged exposure.

Effects on vulnerable residents

Some population groups experience greater health risks from air pollution.

These include:

• Children, particularly those attending schools near busy roads.
• Older adults, who are more vulnerable to respiratory and cardiovascular complications.
• People with asthma or COPD, whose respiratory systems are more sensitive to pollutants.
• Individuals with existing cardiovascular conditions, who face additional health risks.

Short-term and long-term exposure

Short-term exposure involves breathing polluted air over relatively brief periods, such as during a high-pollution episode.

Long-term exposure involves repeated contact with polluted air over months or years.

Both exposure patterns matter when evaluating public health. Even when monitoring results comply with a particular legal objective, reducing unnecessary pollution exposure remains important.

How Do Weather and Seasonal Changes Affect Cardiff’s Air Quality?

Weather influences Cardiff’s air quality by controlling how pollutants disperse, accumulate and react in the atmosphere. Wind, rainfall, temperature, sunlight and atmospheric stability affect pollutant concentrations and create different air quality conditions throughout the year.

Air pollution does not remain at a constant concentration throughout the day or across different seasons.

Weather conditions influence the movement and chemical behaviour of pollutants released from roads, buildings and other sources.

Wind and atmospheric movement

Wind carries pollutants away from their original emission sources.

Stronger winds generally improve dispersion, although they also transport pollution between different locations.

Low wind speeds allow emissions to accumulate, particularly in urban environments with high traffic activity.

Rainfall

Rain removes some airborne particles from the atmosphere through a process known as wet deposition.

This process reduces concentrations of certain pollutants temporarily.

However, rainfall does not eliminate pollution from its original sources. Vehicle emissions and other activities continue producing pollutants.

Temperature and winter conditions

Winter weather influences domestic heating demand and atmospheric conditions.

Increased fuel consumption can produce additional emissions from heating systems and solid-fuel appliances.

Cold, stable atmospheric conditions can also restrict the vertical movement of polluted air, allowing concentrations to increase near ground level.

Sunlight and summer ozone

Strong sunlight encourages chemical reactions involving nitrogen oxides and volatile organic compounds.

These reactions produce ground-level ozone.

Consequently, summer pollution conditions sometimes differ from winter conditions, even when traffic activity remains similar.

Understanding these seasonal patterns helps Cardiff residents interpret air quality information rather than assuming that pollution levels remain consistent throughout the year.

What Measures Are Being Taken to Improve Air Quality in Cardiff?

Cardiff’s air quality improvement programme includes cleaner public transport, traffic management, active travel infrastructure, pollution monitoring and targeted interventions in historically polluted locations. These measures aim to reduce vehicle emissions and protect public health across the city.

Air quality improvement requires coordinated action from local government, transport operators, businesses and residents.

Cardiff Council has introduced different measures through its citywide Air Quality Action Plan and Clean Air Plan.

Castle Street improvements

Castle Street is an important example of targeted pollution reduction.

The area previously experienced nitrogen dioxide concentrations above the annual mean objective. Cardiff’s 2024 monitoring results recorded an annual average of 30 µg/m³.

The council has also developed permanent street improvements, including a segregated cycleway and upgrades to pedestrian infrastructure.

Its plans include improvements to bus stops, paving, drainage, street lighting, signage and road surfacing.

These interventions support cleaner transport and better use of central urban space.

Electric buses and cleaner transport

Electric buses reduce exhaust emissions because they do not produce tailpipe nitrogen dioxide or combustion-related particulate emissions during operation.

Cardiff’s cleaner transport initiatives include the introduction of electric buses.

However, electric vehicles still produce non-exhaust particles through tyre wear, brake wear and road surface contact. Their environmental benefits therefore depend on wider transport and energy policies.

Active travel infrastructure

Active travel refers to everyday journeys made through walking, cycling and other physically active transport methods.

Improving cycling routes and pedestrian facilities encourages residents to choose alternatives to private cars.

Cardiff’s Castle Street cycleway improvements form part of this wider approach.

Taxi and vehicle improvement measures

Taxi grant funding supports the transition towards cleaner vehicles.

Replacing older, more polluting vehicles with lower-emission alternatives helps reduce emissions in busy urban areas.

Vehicle efficiency standards and transport planning also influence long-term air quality.

Remote and hybrid working

Remote and hybrid working arrangements reduce the need for some daily commuting journeys.

Fewer vehicle journeys can reduce congestion and emissions, particularly during peak travel periods.

These measures work best when supported by accessible public transport and safe walking and cycling infrastructure.

What Laws and Environmental Policies Protect Air Quality in Wales?

Air quality in Cardiff is governed by UK environmental legislation and Welsh environmental policies. The Environment (Air Quality and Soundscapes) (Wales) Act 2024 strengthens the Welsh Government’s framework for setting pollution targets and improving environmental protection.

Environmental legislation establishes responsibilities for monitoring pollution, reporting results and implementing improvement measures.

Environment Act 1995

The Environment Act 1995 provides the foundation for Local Air Quality Management (LAQM).

Under this framework, local authorities regularly review and assess air quality within their administrative areas.

Where pollution objectives are not being achieved or are unlikely to be achieved, authorities must designate Air Quality Management Areas and prepare action plans.

Cardiff Council fulfils these responsibilities through its annual air quality reporting programme.

Environment (Air Quality and Soundscapes) (Wales) Act 2024

The Environment (Air Quality and Soundscapes) (Wales) Act 2024 establishes a framework for setting air quality targets in Wales.

Section 2 specifically requires Welsh Ministers to establish an air quality target relating to annual mean PM2.5 concentrations.

The legislation also requires consideration of independent scientific advice and relevant World Health Organization air quality guidelines.

This framework strengthens Wales’s approach to reducing fine particulate pollution and improving public health.

Air Quality Objectives

Air quality objectives provide measurable standards for assessing pollution.

Important UK objectives include:

• Nitrogen dioxide: 40 µg/m³ annual mean.
• PM10: 40 µg/m³ annual mean.
• PM10: 50 µg/m³ daily mean, not to be exceeded more than 35 times annually.

These objectives help local authorities assess pollution conditions and determine whether additional environmental intervention is necessary.

It is important to distinguish legal objectives from WHO health guidelines. Compliance with a legal objective does not mean that air pollution has no health effects.

How Can Cardiff Residents Check Local Air Quality?

Cardiff residents can check local air quality through the Welsh Government’s Air Quality in Wales website and the UK-AIR monitoring service. These platforms provide pollutant measurements, monitoring station information and air quality index updates.

Access to reliable pollution information helps residents understand environmental conditions before travelling, exercising outdoors or spending extended periods near busy roads.

Air Quality in Wales

The official Air Quality in Wales website provides information about monitoring stations across Wales.

Its monitoring site summary includes Cardiff locations such as:

• Cardiff Centre.
• Cardiff Newport Road.
• Cardiff Castle Street.

The website also provides information about air pollution levels and monitoring updates.

UK-AIR

The UK-AIR platform provides pollutant measurements from monitoring stations throughout the UK.

Residents can examine nitrogen dioxide, particulate matter, ozone and other pollutant measurements.

Understanding the Daily Air Quality Index

The Daily Air Quality Index (DAQI) communicates pollution conditions through a numerical scale.

The index uses four bands:

• Low: 1–3.
• Moderate: 4–6.
• High: 7–9.
• Very High: 10.

The index helps people understand short-term pollution conditions and follow appropriate health advice.

People with respiratory or cardiovascular conditions should pay particular attention to pollution alerts and guidance from healthcare professionals.

How Can Residents Help Reduce Air Pollution in Cardiff?

Residents can help improve Cardiff’s air quality by reducing unnecessary car journeys, choosing public transport, maintaining vehicles, avoiding unnecessary solid-fuel burning and supporting cleaner neighbourhoods. Individual actions contribute to wider environmental improvement.

Local government policies are important, but household decisions and everyday transport choices also influence urban emissions.

Residents can support cleaner air through practical behavioural changes.

Choose sustainable transport

Walking, cycling and public transport reduce dependence on private vehicles.

Short journeys completed on foot or by bicycle avoid direct exhaust emissions and reduce traffic pressure.

Cardiff’s developing active travel infrastructure supports these alternatives.

Reduce unnecessary vehicle idling

Leaving an engine running while parked produces unnecessary exhaust emissions.

Switching off an engine when stationary for extended periods helps reduce avoidable pollution.

Maintain vehicles properly

Regular servicing helps vehicles operate efficiently and reduces emissions associated with poorly maintained engines.

Drivers should also follow vehicle emissions requirements and manufacturer maintenance recommendations.

Use cleaner domestic heating

Residents can reduce household pollution by using efficient heating systems and avoiding unnecessary burning of wood, waste or other solid fuels.

Proper maintenance and appropriate fuel choices also help reduce smoke emissions.

Report pollution problems

Residents can report environmental pollution concerns to the relevant local authority.

Examples include persistent smoke from commercial premises, excessive construction dust and suspected industrial pollution.

Shared Regulatory Services provides information about environmental health and air pollution complaints across Cardiff and neighbouring authority areas.

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What Is the Future of Air Quality in Cardiff?

Cardiff’s future air quality depends on maintaining reductions in nitrogen dioxide, addressing fine particulate pollution and expanding cleaner transport infrastructure. Continued monitoring, Welsh environmental legislation and effective local policies will shape the city’s long-term environmental performance.

Cardiff has achieved measurable improvements, but maintaining progress requires continued environmental management.

The 2024 monitoring results demonstrate that nitrogen dioxide concentrations have fallen across the city. However, future planning must consider pollutants beyond nitrogen dioxide, particularly PM2.5.

Fine particulate matter remains an important public health concern because of its ability to penetrate deep into the respiratory system.

Stronger particulate matter targets

The Environment (Air Quality and Soundscapes) (Wales) Act 2024 establishes the legislative framework for PM2.5 targets.

Welsh Government developments concerning fine particulate matter targets will influence future pollution reduction policies.

This approach places greater emphasis on reducing exposure to pollutants associated with long-term health risks.

Cleaner transport infrastructure

Future transport improvements will influence pollution levels throughout Cardiff.

Electric buses, improved cycling infrastructure and accessible public transport can reduce dependence on conventional petrol and diesel vehicles.

Street improvements also support safer walking routes and more sustainable travel.

Continued monitoring and environmental assessment

Regular monitoring remains necessary to determine whether Cardiff’s air quality improvements continue.

Authorities must examine changing traffic patterns, new developments and pollution levels around residential neighbourhoods.

Future assessments will also help determine whether existing Air Quality Management Areas remain necessary.

Public participation

Residents, businesses and community organisations have an important role in supporting cleaner air.

Public participation in environmental consultations helps local authorities understand neighbourhood concerns and identify opportunities for improvement.

Continued cooperation between Cardiff Council, the Welsh Government, transport operators and local communities will remain essential.

Is Air Quality Improving in Cardiff?

Air quality in Cardiff has improved considerably over recent years, particularly in relation to nitrogen dioxide pollution. The city’s 2024 monitoring results demonstrated compliance with the annual nitrogen dioxide objective across all monitored locations, including its four designated Air Quality Management Areas.

The 36% reduction in nitrogen dioxide concentrations since 2019 and the improvement recorded on Castle Street demonstrate the progress achieved through monitoring, transport management and cleaner mobility initiatives.

However, air pollution remains an important public health and environmental issue. Fine particulate matter, vehicle emissions, domestic heating and construction activities require continued attention.

Cardiff’s future environmental performance depends on maintaining existing improvements, implementing effective Welsh air quality policies and encouraging sustainable transport.

For residents, regularly checking official pollution information and making cleaner everyday travel choices provides a practical way to support a healthier urban environment.