Particulate pollution emitted from vehicle exhausts has long been a health concern, not just for road users but for anyone who breathes the air in our major town and cities.
Air quality regulation around the world has led to significant reductions in such exposure, although Australian standards continue to lag well behind.
But just as bike riders were beginning to think that we could breathe easier we’ve been ambushed by a new villain: tyre wear emissions.
It turns out that modern tyres—combined with bigger vehicles, more power, and harsh driving habits—are continually spewing large volumes of potentially harmful tiny particles into the air.
Recent tests have shown that tyres are typically shedding almost 2000 times the amount of particulate pollution than the exhaust of a recent model car.
Clearly so called “zero-emission” vehicles will be far from it.
It is only recently that researchers began measuring the tyre particles in the air, and at first there was disbelief at the findings.
Now, in recent research by Emissions Analytics in the UK, more detail study has revealed that the figures are much worse than first thought.
And what is worrying health experts is the amount of toxic compounds that are present in the tread of modern tyres.
And it is not just the compounds we are breathing in that are of concern.
Recently an additive used in tyre rubber was discovered to be the culprit in mass deaths of salmon in north American rivers where it ended up after washing off roads.
Emissions Analytics found that the mass wear from new tires is 16 times greater than the maximum permitted from the tailpipe, but 3,650 times greater than actual tailpipe emissions.
It also found that there was a risk that electric vehicles, aggressively driven, could massively increase tyre emissions: Half a tonne of battery weight can result in tyre emissions that are almost 400 more times greater than real-world tailpipe emissions, everything else being equal.
The researchers performed chemical analysis of the potentially toxic compounds in tyres that showed that the most toxic tyre was three times worse than the least toxic.
You can find more information here.
This article was made possible by the support of Bicycle Network's members who enable us to make bike riding better in Australia.