In just four years, the Brussels Capital Region’s low-emission zone (‘LEZ’) has helped to produce a significant reduction in air pollution, demonstrating how this traffic regulation measure visibly improves health and environmental conditions in cities.

For the first time since the establishment of the low-emission zone in 2018, nitrogen dioxide (NO2) levels have decreased by a record 30% along the major roads of the Belgian capital, the latest report by Brussels’ Environmental authority shows. The study points to a similar or even more marked reduction of other harmful pollutants.

“By progressively removing the most polluting vehicles from the road, the low-emission zone significantly contributed to improving air quality and people’s health in Brussels,” the city’s environmental authority said in a statement.

The two maps below chart the evolution of air quality levels across the Brussels Capital Region in 2018 and 2022.

This model was a collaboration between the Leuven Catholic University and Bloomberg Philanthropies. 

The 2018 map, on the left, reveals large yellow stains and red lines associated with high concentrations of carbon dioxide at the time. In the 2022 map, to the right, the yellow and red lines have gradually shrunk and turned into green, the colour indicating lower carbon dioxide concentrations.

Over the past few years, other factors such as an increase in sustainable transport travel and teleworking contributed to clearing the air in the city.

In addition, since August 2022, the ‘Good Move’ plan to overhaul mobility in Brussels’ city centre decreased car traffic by 27 percent and boosted cycling uptake by 26 percent.

More work ahead

In spite of this, air pollution remains a significant issue in the Belgian capital, where it is primarily linked to road traffic.

Scientific data across the country highlights the danger that harmful air particles pose to people’s health: in Belgium, exposure to three pollutants – fine particulate matter, nitrogen dioxide and ozone – led to 5,330 premature deaths in 2020, a European Environment Agency report shows.

Over a mere four-year span, Brussels’ low-emission zones have proven to be a powerful answer against this emergency.

Between 2018 and 2022, the introduction of the first low-emission zone halved the number of diesel vehicles in the city. New restrictions in 2022 extended the ban to additional vehicle categories, with visible results: the latest measures cut particulate matter (PM2.5) emissions by 30%, black carbon by 62% and brought down the share of older diesel vehicles not equipped with particle filters from 14% to 3%.

Brussels local authorities will tighten the low-emission rules again in 2025, and introduce additional restrictions in the following years. By 2035, all internal combustion engine vehicles will be banned, except for heavy goods vehicles and coaches.

Alain Maron, the Brussels Minister for the Environment and Climate Transition, said these measures are forecast to save people’s lives and bring significant financial benefits.

“According to a recent study, the gradual phase-out of combustion engines will help us avoid 110 premature deaths per year and save 300 million euro in healthcare costs,” Maron explained, citing a report by VITO, a Belgian research organisation.

To offer residents alternative ways to move around, Brussels is ramping up actions to ease the transition to emission-free transport and reduce reliance on combustion-engine vehicles.

For example, almost 20% of the regional budget is devoted to strengthening public transport. For electric vehicle drivers, a network comprising 4,000 e-charging points is available across the Brussels Capital Region.

New air quality standards

However, efforts to alleviate heavy-congestion in the Belgian capital – as elsewhere in Europe –  need to be paired with a larger, holistic approach.

For the World Health Organisation, air pollution poses one of the greatest environmental health risks to humans worldwide, and is directly linked to heart and lung disease, stroke and lung cancer.

Exposure to harmful pollutants is a main concern for cities where road traffic generally causes higher pollution levels.

“The Brussels Region’s LEZ may serve as an inspiration for other local authorities on how to efficiently tackle air pollution. This is crucial since the new Ambient Air Quality Directive (AAQD) will ask cities to pursue additional air quality objectives in the future, ” remarked Thomas Lymes, Policy advisor for Mobility and Air Quality at Eurocities.

The directive might offer extra tools for local governments, and includes a firm commitment to achieve safe air quality levels by 2050, as well as a short-term target for 2030. The final text is currently being discussed by the EU institutions.