So much for ULEZ’s health boost? Study found Birmingham’s Clean Air Zone reduced air pollution by just 7% – HALF what was previously claimed

The day motorists across London have been dreading finally arrived this week, as the Ultra Low Emission Zone (ULEZ) doubled in size.

The new zone now covers all London boroughs and has resulted in thousands of motorists facing a £12.50 per day charge.

While Mayor of London Sadiq Khan claims the expansion will bring cleaner air to five million more people, a new study challenges those claims.

Researchers from the University of Birmingham have studied the impact of Birmingham’s Clean Air Zone, which covers an area of ​​the city center within the A4540 Middleway.

While the zone is said to have reduced air pollution by 13 percent, the new study shows that that figure is actually just 7 percent.

Researchers from the University of Birmingham have studied the impact of Birmingham’s Clean Air Zone, which covers an area of ​​the city center within the A4540 Middleway

Birmingham’s Clean Air Zone (CAZ) was introduced in June 2021 and focuses on reducing levels of nitrogen dioxide (NO2) produced by older cars and trucks.

It involves charging the owners of more polluting vehicles a fee to enter the zone – similar to London’s ULEZ system.

Scientists from the University of Birmingham analyzed the emissions in the first seven months after the CAZ went into operation.

In the zone, pollution is said to have typically decreased by 13 percent.

However, the team argued that calculating the reduction in pollution is complex and must take into account weather and seasonal effects.

Their calculations show that the NO2 levels have only fallen by around seven percent, i.e. around half of the estimated value.

The day motorists across London have been dreading finally arrived this week, as the Ultra Low Emission Zone (ULEZ) doubled in size

The largest decreases were seen at busy roadsides within the Zone, such as the CBD, while there were also some ‘spillover’ effects to areas outside the CAZ.

They described the change as “modest but significant” and added that there was no “detectable impact” on the concentration of fine particulate matter in the air, also known as PM2.5.

The lead author Dr. Bowen Liu said: “As predicted, the CAZ in Birmingham has reduced NO2 pollution, but it has had no discernible impact on the concentration of fine particulate matter PM2.5 – the air pollutant with the greatest impact on health.”

Professor Zongbo Shi, senior author, added: “PM2.5 surveillance at Birmingham sites still regularly exceeds WHO quality guidelines, resulting in health impacts with significant consequences, including hundreds of premature deaths each year.”

The results were published in the journal Environmental & Resource Economics.