High levels of air pollution cause not only physical complaints, but also increased numbers of cases of mental problems, according to a study carried out by the Independent Sickness Funds and confirmed by the university of Leuven.
The research shows that on days of high levels of air pollution, the number of people suffering from an inability to work due to mental problems like burnout and depression also increases.
The Funds took their own figures for sick-days off work in 2019 and compared them with figures from the Interregional Environment Cell Ircel, which monitors pollution levels in all three regions, De Standaard reports.
To everyone’s surprise, the comparison has never been done before. But the figures tally perfectly: high levels of pollution on bad days coincided with 12,270 cases of people taking days off work.
The numbers can even be related directly to the cause: an increase in the soot particles known as black carbon of 0.5micrograms (μg) per cubic metre led to 3.5% more diagnosed complaints.
When the pollution by carbon dioxide rose by 5μg per m³, cases of inability to work rose by 4.2%. Cases were established either on the day of the peak itself, or up to two days later, demonstrating the acute nature of the event, the study suggests.
“Those are significant numbers,” Luk Bruyneel, one of the authors of the study, told the paper.
“A quarter of the approximately half a million people who end up incapacitated for work each year, suffer from a mental disorder. That means more than 100,000 people. Couple that with the fact that the increases in air pollution that we have taken into account often occur, sometimes they are even higher.”
In the summer, when people are more exposed to the air outside, the effect is even more pronounced.
“We are not saying that air pollution causes depression or burnout, there are many other factors involved,” emphasised Bruyneel, “but a day with a peak in bad air can be the trigger, the straw that breaks the camel’s back, let’s say.”
Professor Tim Nawrot, an expert in environment and health at the KULeuven, said the study was sound.
“It refers to a large group of people from the working population, which is rare. The results are in line with other studies. Air pollution has also previously been linked to higher risks of anxiety and suicide,” he said.
“Thirty years ago the focus was on damage to the respiratory system, then it shifted to cardiovascular disease and now we are paying more and more attention to mental disorders.”
The study is seen as important because days off work cost the economy some €9 billion, and the share of mental problems, as people become more willing to reveal the issue, is growing as a part of the total.