Air quality in Cardiff is better than during the pandemic

Ted Peskett Local Democracy Reporter

Air quality in terms of levels of nitrogen dioxide in Cardiff is better than it was during the pandemic, city council data shows.

Cardiff Council’s environmental scrutiny committee met to discuss air pollution in the city at a meeting on Thursday, December 5.

In the meeting members were presented with data on annual average roadside concentrations of nitrogen dioxide in Cardiff that shows levels increasing from 20μg/m³ to about 24μg/m³ between 2020 and 2021.

Data

The data, presented in a graph, then shows levels decrease steadily to about 19μg/m³ in 2023.

The level of nitrogen dioxide in Cardiff is monitored at 135 locations across the city using diffusion tubes.

Cardiff Council’s operational manager for enterprise and specialist services, Jason Bale, said improvements in air quality were down to a combination of factors including changes to the types of vehicles people drive and their travelling habits.

Mr Bale said: “Whereas you used to have a large AM and PM peak pre-Covid that seems to have dissipated and traffic travel seems to have changed in terms of the types of journeys and the journeys being undertaken at set times in the day.”

Wider benefit

The council officer said it would be difficult to indicate whether the implementation of 20mph limits has directly led to improvements in air quality.

However he added that a potential wider benefit of the measure was that it had encouraged active travel and reduced the number of car journeys.

Scrutiny committee members also heard how, apart from one site, all of the nitrogen dioxide monitoring locations across the city were within the nitrogen dioxide annual objective limit set by the Welsh Government (40μg/m³) since 2019.

The anomaly was site 212, which is located near the Bridge Street roundabout in Llandaff.

In 2019 it recorded nitrogen dioxide levels of 41μg/m³. Levels have since decreased to 35μg/m³.

Selected locations in the city where there are high concentrations of traffic, including Castle Street, remain a focus in terms of air-quality monitoring according to the council.

In April 2023 Cardiff Council’s cabinet endorsed plans to allow general traffic to continue using Castle Street.

The road was shut to all traffic in summer 2020 before re-opening to just buses and taxis in the autumn of that year.

Following a public consultation Castle Street was re-opened to general traffic in June 2021 as a temporary measure.

Issues

Although council officials said the current scheme that’s in place will be kept the same some work will still be needed.

Mr Bale said: “The scheme that is currently in place is an interim scheme. The materials that have been used are not fully compliant for a lifelong scheme.

“There [are] issues around some of the bus crossings, their compliance in terms of road safety standards, and so the final scheme that will go in will be a permanent version of the scheme that’s there with better-constructed materials.”

The local authority hopes that by keeping Castle Street permanently open to general traffic traffic flow across the city will be improved and levels of nitrogen dioxide in the city’s wider road network will not worsen.

In its latest update on air quality Cardiff Council said the Deputy First Minister has accepted the final plan and preferred option for Castle Street.

The council has so far received funding of £262,000 from the Welsh Government for the work on the road and consideration will be given for a further £7m.