NO₂ is normal, but for how long?

From January to December 2024, the sixth national campaign to measure the concentration of nitrogen dioxide (NO₂), an indicator pollutant directly linked to road traffic, took place in Luxembourg. Monitoring was carried out at 130 locations across the country in co-operation with Klima-Agence and 36 communes. At no site did the recorded level exceed the current European standard of 40 µg/m3. The highest level (32 µg/m3) was recorded in Echternach, remaining within the permissible limits.

However, from 2030, a new standard of no more than 20 µg/m3 will come into force in the EU. Although most locations already meet the future standard, some sites still remain above the threshold. This is particularly the case in dense urban agglomerations and busy roads, mainly in the south of the country and near the eastern border. Elevated values are consistently recorded in the Echternach area.

Since 2018, there has been a steady downward trend in the average annual NO₂ level. This is fuelled by the renewal of the vehicle fleet, the growing number of electric vehicles, EURO environmental standards and, to a certain extent, the persistence of remote working. At the same time, there are seasonal fluctuations: in January 2024, due to unfavourable weather conditions (inversion, low winds, dry weather) the pollution level was higher, while in August it was significantly lower due to school holidays and reduced traffic.

In 2024, 36 communes participated in the campaign, with an additional 8 sites measured directly by the Environmental Administration - in Luxembourg, Esch-sur-Alzette, Remich, Wiltz and Beidweiler. The capital, which has its own monitoring system, remains a key player: its data are available at vdl.lu.

Although current results are in line with standards, more efforts are needed until 2030. The new EU Air Quality Directive, adopted in November 2024, obliges member states to strengthen monitoring and take measures in vulnerable areas. The authorities are calling on public utilities that have not yet participated in such measurements to join the initiative to ensure a healthy and clean atmosphere for all residents.