Unseen Car Emissions
As many predicted, 2020 was a breakthrough year for electric car adoption, with a significant increase in worldwide sales alongside a growing number of people recognising their important role in fighting the climate crisis.
Much of this progress has come as consumers have led the way, opting for EVs due to their lower running costs, as well as their human and planetary health benefits.
It is this awareness of just how harmful exhaust emissions are for human health, as well as their inherent role in worsening the climate crisis, that is driving progress and causing manufacturers to step-up and commit to only producing electric-only vehicles in the near future.
While it is heartening to see such quick progress on this front, it demonstrates the importance of educating people about the other harmful emissions created by cars so that we address the problem as a whole.
Today we look at the other emissions that cars produce, the lack of legislation surrounding them, and why manufacturers must step up to meet these issues.
Non-Exhaust Emissions
The term Non-Exhaust Emissions (NEE) applies to any harmful emissions produced by a vehicle which do not come directly from their engine or exhaust. Primarily this relates to the particulate matter produced by brakes and tyres.
While the average driver probably only thinks about their brakes and tyres when their NCT is due, they account for a large percentage of the harmful emissions produced by your car. In fact, a study by the European Commission’s Joint Research Centre found that “exhaust & non-exhaust sources contribute almost equally to total traffic-related PM10 emissions”.
PM10 refers to particulate matter – very small particles of air pollution – that have a diameter or 10 micrometers (0.01mm) or smaller.
Their tiny size means that they are easily inhaled into your throat and lungs, which can greatly worsen heart and lung conditions. You can see this in action when you visit a busy, polluted city and end up with black bogies for the next few days.
Major Source of Microplastics
While some may consider this to be yet another alarmist thing to worry about, the consequences of NEE are incredibly wide-reaching, with more than 200,000 tonnes of microplastics entering the oceans every year according to a 2020 study published in Nature Communications.
To put that into context, the average tyre loses 4kg in weight during its lifetime from the constant wear and tear that it experiences.
These balls of microplastic bounce to the side of the road where they are blown by the wind, or washed by the rain, into river systems and then on into the ocean. Those marine animals that aren’t killed by the microplastics usually ingest them – including the fish that we eat.
The rise of electric cars will cause exhaust emissions to lower, but we should be aware of other forms of pollution created by our cars. Credit: Green Car Congress
Andreas Stohl, of the Norwegian Institute for Air Research, who led the study said the following in an interview with The Guardian: “Roads are a very significant source of microplastics to remote areas, including the oceans. It’s such a huge amount of plastic compared to, say, clothes. You will not lose kilograms of plastic from your clothing.”
The issue of pollution from tyre wear has been significantly worsened by the increasing number of SUVs and other crossover vehicles on the road, according to Emissions Analytics’ 2020 report, due to their increased size and weight causing greater levels of abrasion as they take more energy to stop.
“There is currently no legislation in place to limit or reduce Non-Exhaust Emissions”
See our article SUVs Are Killing The Planet for more on how these vehicles are increasing exhaust emissions and leading to higher numbers of road deaths.
Yet, there is currently no legislation in place to limit or reduce NEE.
Richard Lofthouse, Senior Researcher at Emissions Analytics said: “It’s time to consider not just what comes out of a car’s exhaust pipe but particle pollution from tyre and brake wear. Our initial tests reveal that there can be a shocking amount of particle pollution from tyres – 1,000 times worse than emissions from a car’s exhaust.”
“What is even more frightening is that while exhaust emissions have been tightly regulated for many years, tyre wear is totally unregulated – and with the increasing growth in sales of heavier SUVs and battery-powered electric cars, non-exhaust emissions (NEE) are a very serious problem.”
Braking the cycle
Alongside emissions from tyres, the particulate created from vehicle brakes is another major concern.
Formula 1 provides an extreme illustration of the tyre debris and particulates which end up in rivers and oceans. Credit: Red Bull Racing
The Joint Research Centre’s research concluded that:
“Brake, tyre and road wear along with road dust re-suspension have been recognized as the most important non-exhaust traffic related sources, with their relative contributions to non-exhaust traffic related emissions ranging between 16-55% (brake wear), 5-30% (tyre wear) and 28-59% (road dust re-suspension)”
The study concluded that approximately 50% of total brake wear is emitted as airborne PM10, and therefore poses a direct threat to human health.
Interestingly, while tyre wear will not be reduced by switching to an electric car, the harmful air pollution from braking just may be.
In January 2021, the University of Birmingham published a study demonstrating that EVs are less polluting in urban areas as they rely on their motors to slow the car when using regenerative braking, rather than using the brake pads themselves.
The researchers found that using the motor to slow the car lowers the amount of PM10 emissions produced by electric vehicles by around 26% compared to internal combustion engine cars.
This reiterates the findings of a 2017 study in Los Angeles by SEA, which showed that electric vehicles use their brakes about one-eighth of the time compared to petrol or diesel cars.
What Next?
We find ourselves at a crucial time in history where the public, politicians, and automotive manufacturers are finally recognising the crucial role that vehicles play in the climate crisis – and their harmful impact on human health.
While the switch to electric cars will help address many of the issues, it is important during this time of unified reflection that we must start to legislate for the sustainable future that we all want to see.
As such, it is clear that we must legislate against Non-Exhaust Emissions as much as we legislate against the harmful pollution that is emitted via exhausts.
The ecological and human health benefits are undeniable, and it is beyond the means of consumers to address these issues – aside from making the switch to EVs with regen braking. The responsibility to tackle this issue lies with lawmakers, as well as automotive and tyre manufacturers.
Given that the latter have been slow to act on exhaust emissions, it would seem that our hopes lie with politicians to introduce legislation to monitor, limit and reduce NEE.
What To Read Next
15-Minute Cities
Discover how the 15-minute city concept could help Ireland reduce its carbon footprint, while also reducing rents and improving quality of life
Pollution Exposure Rises While Driving With Open Windows
Driving with the windows open increases your exposure to harmful emissions by more than 90% according to new University of Surrey research
Speed Limits: Improving Public & Environmental Health
Find out how a 30kph speed limit in urban areas could save lives, reduce heart disease, and tackle climate change