Traces of additives typically used in the manufacture of tires have been detected in all the most commonly consumed fruits and vegetables in Switzerland. This is indicated by a study of the EPFL and the Federal Office for Food Security and Veterinary Affairs (OSAV) published in the “Journal of Hazardous Materials”. scientists ignore the long -term consequences of this exposure on human health at this stage. Additional studies will have to specify.
This research follows the quote in August 2023 of two Austrian studies showing the presence of these additives on leafy vegetables in the “K-Tip” German magazine. After this publication, which caused a stir, the OSV contacted the researcher Florian Breider, director of the Central Environmental Laboratory (GR-CEL) at the EPFL, in order to investigate this question in Switzerland by taking into account a wider range of vegetables. “We have built this study together, taking around a hundred fruits and vegetables among the most consumed in Switzerland at nine representative distributors, ranging from large brands to organic markets and small neighborhood grocery stores,” explains Florian Breider.
After rinking and transformed fruits and vegetables into samples, scientists seek the presence of eleven components typically present in tire additives. Thanks to the statistical consumption data in possession of the OSV, the study made it possible to establish a theoretical daily exposure rate to these molecules by ingestion. Result: 31% of samples contain traces of these substances, including the 6ppd and the 6pp-quinone. And this, regardless of the origin of fruits and vegetables and whether organic or not. “The diet being generally the same throughout Western Europe, one can imagine that these figures are representative of exposure to these particles in neighboring countries,” says Florian Breider.
Only studies on rodents have to date establish the toxicity of tire additives on mammals, in particular the DPG, the 6PPD and the 6PPD-Quinone. With the results of a drop in male fertility and the occurrence of neurotoxic and neuroinflammatory effects. The critical threshold for humans is not yet known. “We do not know how these molecules are metabolized by the human body, we must therefore be interested in it, because we are all exposed there and probably in particular certain categories of the population, such as road workers,” said Florian Breider. To find out more, Chinese laboratories are currently carrying out in -depth studies on its population by analyzing the presence of these substances in blood and urine. At the EPFL, the GR-CEL plans to get down to it in the coming months.
-Exposure to tire additives comes from their wear on the road. Tires contain additives such as antioxidants and vulcanizing agents (to guarantee the adhesion, elasticity and resistance of rubber) whose toxicity is still unknown. These particles propagate in the atmosphere, are deposited on the floors or are transported by runoff. We are exposed as much by inhalation as, as the study demonstrates, by the ingestion of food.
A study published in 2017 estimates that around 6 million tonnes of these additives are released in the environment each year. The exposure does not spare rural areas, according to another Norwegian study published in 2023, because the frequency of road traffic is not significant. An EPFL study has even shown that these components were found in the Alpine lakes. “We can compare this exposure to those of other micropollutants. It is a diffuse background in which we bathe without knowing if it is a priority to better control these substances, for example by replacing them with less toxic alternatives during the manufacture of tires ”.
To avoid the transfer of the road to the environment, studies aimed at depolluting roads are currently underway in Switzerland. Several studies have shown that aggressive driving, with sudden accelerations and braking, aggravated the wear of tires and therefore the transfer of these particles to the atmosphere, soil and surface water.
