April 2020 photo shows the bridge in Remich closed. Traffic was permitted via other bridges which were closely monitored by police
The first 2020 lockdown gave parts of Luxembourg a breather as traffic almost ceased. But there are other pollutants that were not impacted. Expert Andreas Krein explains.
As a thoroughfare for commuters between Luxembourg and Germany, the Remich bridge fell eerily silent when German authorities introduced border checks during the first lockdown of 2020. It wasn’t just noise pollution that vanished. Researchers found concentrations of nitrogen dioxide (NO2), a pollutant which causes inflammation of the airways and led to 54,000 premature deaths in 2018, fell dramatically. “It was super,” Andreas Krein, senior R&D associate at the Luxembourg Institute of Science and Technology told Delano.
While this example mirrors the situation in cities all over Europe, some of which reported a 60% drop in NO2 in April, according to the 2020 Air Quality Europe report, less traffic resulted in a temporary fix to just one major pollutant.
“Everyone thinks that dust in the atmosphere is from chimneys and cars. It’s not the case,” Krein says. Some pollutants remained unchanged or increased over the year.
Photo: List. List uses this mobile air quality vehicle to collect air samples in different locations around the grand duchy
The agricultural sector’s use of slurry to fertilise fields, for instance, releases ammonia which reacts and forms secondary fine particulate matter that becomes PM2.5 (particulate matter with a diameter of 2.5 μm or less). Far deadlier than NO2, it was responsible for 379,000 premature deaths in the EU in 2018.
Farming is not the only source: street dust from tyre matter and other waste which, during dry spells of which there were many in 2020, is suspended in the air and adds to this particulate matter, leading to asthma and lung diseases.
The fact that 2020 was the hottest year on record for Luxembourg, also brought a boost to ozone levels. This pollutant that causes chronic respiratory diseases, but paradoxically becomes more widespread when there are lower NO2 levels. “A clearer atmosphere leads to more ozone,” Krein explains, saying that if we have more heatwaves, little can be done about it beyond early health warning systems. “This is a problem not only for humans as it affects eyes and lungs but it also poses problems to vegetation: leaves on trees and crops. They suffer from ozone. Ozone is mainly a problem in the rural parts of the country,” he says.
Andreas Krein, pictured, is senior R&D associate at the Luxembourg Institute of Science and Technology. Photo: List.
While levels have fallen dramatically in recent years, monitoring in Luxembourg by the environment ministry in 2018 found NO2 levels repeatedly exceeding the European Commission threshold in seven communes, most of them located on commuter thoroughfares, for instance in Hesperange. Esch-Gare, meanwhile, consistently exceeded the average NO2 threshold in 2018 and 2019. Krein stresses that these levels are concentrated within very close range of major roads where there are no habitations. There is, however, an impact on human life—the European Environment Agency reported 40 premature deaths in Luxembourg as a result of NO2 exposure and ten as a result of ozone in 2018.
The next big preoccupation for Krein is the presence and impact of nanoparticles, minute dust particles which directly enter the human blood via the lungs. Normally, they will become attached to PM10 or PM2.5 but by removing these larger particles, nanoparticles can circulate unchecked. “There are many investigations on health issues of these types of particles and the harm they cause. That’s a future problem but it’s not quite clear how to handle this,” says Krein.