Remote-sensing: ‘5% of diesel cars in Brussels emit 90% of particles’

Diesel cars in Brussels emit a disproportionate amount of polluting substances in the air. A small number of those cars are responsible for of large part of the air pollution in Brussels. That is the conclusion of a remote-sensing study by the Brussels Region. The study shows that it’s about time to remove the most polluting vehicles from Brussels’ traffic.

The initiative for the study comes from TRUE – The Real Urban Emissions Initiative – and is a measuring project of the International Council on Clean Transportation (ICCT). In the autumn of 2020, researchers of Brussels Environment and the ICCT launched a unique remote-sensing study.

Striking conclusions

Together, they analyzed the emissions of 130 000 diesel cars in real traffic situations. The study contained more than 260 000 measurements and was financed by the FIA Foundation and Bloomberg Philanthropies.

Some conclusions of the study were striking. For example, the researchers discovered that real driving emissions in Brussels are largely exceeding the legal limits and that 5% of cars that should be equipped with a particle filter – in reality – emitted 90% of all particles emitted by the tested group of vehicles.

Euro standards

The results showed that Euro 4 diesel cars – although representing only 12% of the analyzed test sample – were responsible for almost half of particle emissions and one-quarter of nitrogen oxides. As a result, this type of vehicle will no longer be allowed in the city from 2022.

Euro 5 diesel cars, representing hardly 20% of the actual fleet, and the category that needs to disappear as of 2025, are responsible for 40% of nitrogen emissions.

Particle matter

The study also revealed detailed information about particle matter. For example, the analysts discovered that in 5% of the cases, diesel cars that should be equipped with a particle filter, the filter was malfunctioning or removed, making this category of cars responsible for 90% of total particle pollution in Brussels.

All collected data of the study also indicated that the real performances of the most recent vehicles were far better than those of old diesel cars. Nevertheless, the former still produce more emissions than expected – all the more reason to accelerate the introduction of the stricter Euro 7 standard.

Quality of life

The study confirms that it’s not a day too soon to ban those polluting cars from the city. The Brussels Capital Region introduced the low-emission zone at the beginning of 2018 to improve the air quality in the city. The next steps are a ban on diesel cars by 2030; the phasing out gasoline and LPG cars is planned for 2035.

“In the meantime, we have to make arrangements to fight particle filter fraud,” Minister of Health and the Environment, Alain Maron (Ecolo), said during the presentation of the study on Monday.

“Quality of life in Brussels will improve significantly by banning cars with an internal combustion engine.” Minister Maron also emphasized the importance of the systematic check of particle filters during the technical inspection the three Belgian regions will introduce next summer.

9 000 premature deaths

Air pollution is an issue in Belgium. Every year, air pollution causes 9 000 premature deaths, of which 1 000 in Brussels only. Polluted air causes respiratory and cardiovascular diseases and is responsible for a considerable economic cost for society.

Also, in asthma patients and people who suffer from cystic fibrosis, symptoms worsen. In the meantime, scientists know that air pollution impacts cognition and dementia.