NO2 levels fall 20% in Glasgow since launch of Low Emission Zone

Nitrogen dioxide levels in Glasgow city centre have dropped by 20% since the roll-out of a Low Emission Zone (LEZ) to all vehicle types in June 2023.

Diffusion tube monitoring also showed a 15.3% drop in NO2 concentrations at locations outside the city centre.

Alongside diffusion tube monitoring, air pollution is also recorded by 11 automatic monitoring stations around the city. Like the previous year, all stations logged NO2 concentrations below the legal objective, but 2023’s results showed further decreases in levels of this pollutant, said Glasgow City Council.

However, the data for 2023 did highlight areas of concern, said the council. It noted that diffusion tube monitoring on Gordon Street and under the Hielanman’s Umbrella showed “marginal exceedances” of NO2 targets. And while all automatic monitoring stations showed compliance with the legal levels, “the station on Hope Street only narrowly met the objective - a repeat of 2022’s result”.

Cllr Angus Millar, Convener for Transport and Climate said: “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 the council updated its Air Quality Action Plan. Its priorities include:

• A review of air quality monitoring - with a focus around schools, hospitals and care homes.
• The continuation of vehicle idling awareness campaigns and enforcement.
• Supporting transport strategies which benefit air quality.
• Supporting the expansion of our active travel network.

Elsewhere in Scotland, there are also Low Emission Zones in Dundee, Aberdeen and Edinburgh.