Glasgow’s Low Emission Zone is having a promising impact on air pollution according to new data released.

The latest Air Quality Annual Progress Report shows that levels of nitrogen dioxide in the city centre and LEZ area has dropped by 20 percent compared to diffusion tube monitoring from the previous year.

The annual report is the first to consider pollution levels during LEZ enforcement following the scheme’s full roll-out to all vehicle types on 1 June 2023.

It remains too soon to determine the full impact the LEZ has had on air quality. That’s mainly because the LEZ was only in place for the final seven months of 2023, while zone residents and non-compliant taxis were afforded additional time to move towards compliance.

Zone residents didn’t need to comply with the LEZ until June 1, 2024 with 778 exemptions handed to taxis for the first year.

There was also a 15.3% drop in nitrogen dioxide concentrations at locations outside the city centre.

Nitrogen dioxide and airborne particulate matter are the main pollutant concerns in Glasgow and the annual report assesses air quality so that they can be compared against legal requirements.

In addition to diffusion tube monitoring, there are eleven automatic monitoring stagions around the city. All stations recorded concentrations below the legal objective but 2023’s results showed further decreases in the level of pollution.

There were areas of concerns highlighted by the data with diffusion tube monitoring on Gordon Street and under Hielanman’s Umbrella showing marginal exceedances of the legal requirements, while the automatic station on Hope Street only narrowly met the objective – a repeat of 2022’s result.

But while it is too soon to fully understand the impact on air quality, initial results from monitoring are promising and it is expected that further improvements can be expected in years to come.

Cllr Angus Millar, City Convener for Transport and Climate said: "Air pollution contributes to hundreds of deaths in Glasgow each year, as well as exacerbating long-term health inequalities and the health conditions of thousands of Glaswegians.

“Glasgow’s Low Emission Zone was introduced to address stubbornly high levels of air pollution in the city centre – and with Dundee, Aberdeen and Edinburgh now implementing their own LEZs, Scotland’s cities have joined hundreds across Europe in taking this kind of action to improve air quality.

“The early progress recorded in Glasgow in 2023 – with a 20% drop in the city centre’s nitrogen dioxide levels – is really encouraging. With some locations still showing breaches of legal limits, however, the impact of the LEZ’s full roll out will only become clear with next year’s annual monitoring data, and Glasgow will continue our work to seek cleaner, more breathable air that meets legal requirements.”

Earlier this year, Glasgow set out refreshed plans to tackle pollution across the city. It is a citywide approach but there remains a level of focus on the city centre due to its pollution levels.

It includes a review of air quality monitoring with a focus around schools, hospitals and care homes, continuing vehicle idling awareness campaigns and enforcement, supporting transport strategies which benefit air quality and supporting the expansion of the city’s travel network.

With taxis working to become compliant, it was revealed last month that one of the only companies permitted to make LEZ-compliant upgrades to taxis suddenly went bust.

It was reported that 225 taxi operators were still driving under exemptions that are due to expire in October and have now been unable to make the change – potentially putting their jobs at risk.

The company employed to carry out the upgrades, Vehicle Repowering Services (VRS), went into liquidation in late July, despite having a “waiting list for conversions.”