The conclusions are from Emission Analytics, an independent entity that performs emissions tests on vehicles under real conditions. After several tests, it concluded that particulate emissions due to tire wear, and also from the brakes, can be 1000 times higher than those measured in the exhaust gases of our cars.
It is well known how harmful particulate emissions are to human health (asthma, lung cancer, cardiovascular problems, premature death), against which we have seen the justified tightening of emission standards — consequently, today the wide Most commercial automobiles come with particulate filters.
But if exhaust emissions have been increasingly strictly regulated, the same is not happening with particulate emissions resulting from tire wear and the use of brakes. In reality there is no regulation.
And it's an environmental (and health) problem that has been progressively getting worse, due to the (still growing) success of SUVs, and also the growing sales of electric vehicles. Why? Simply because they are heavier than equivalent light vehicles — for example, even in compact cars, there are differences of 300 kg between those equipped with a combustion engine and those equipped with electric motors.
Particles
Particles (PM) are a mixture of solid particles and droplets present in the air. Some (dust, smoke, soot) may be big enough to see with the naked eye, while others can only be seen with an electron microscope. PM10 and PM2.5 refer to their size (diameter), respectively, 10 micrometers and 2.5 micrometers or smaller — a strand of hair is 70 micrometers in diameter, for comparison. As they are so small, they are inhalable and can become lodged in the lungs, resulting in serious health problems.
Non-exhaust particulate emissions — known in English as SEN or Non-Exhaust Emissions — are already considered as the majority emitted by road transport: 60% of the total PM2.5 and 73% of the total PM10. In addition to tire wear and brake wear, this type of particulate can also arise from road surface wear as well as the re-suspension of road dust from vehicles passing over the surface.
Emissions Analytics carried out some preliminary tire wear tests, having used a familiar compact (double-pack body) equipped with new tires and with the correct pressure. Tests revealed that the vehicle emitted 5.8 g/km of particulates — compare with 4.5 mg/km (milligrams) measured in the exhaust gases. It is a multiplication factor greater than 1000.
The problem is easily aggravated if the tires have a pressure below ideal, or the road surface is more abrasive, or even, according to Emissions Analytics, the tires are among the cheapest; viable scenarios under real conditions.
Particle emission solutions?
Emission Analytics considers it essential to have, in the first place, regulation on this subject, which at the moment does not exist.
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In the short term, the recommendation is even to buy top quality tires and, of course, monitor the tire pressure, keeping it in accordance with the values recommended by the brand for the vehicle in question. However, in the long term, it is essential that the weight of the vehicles we drive on a daily basis also decreases. A growing challenge, even a consequence of the electrification of the car and its heavy battery.