No simple answers
I believe there’s a basic human drive to answer questions, solve problems, and develop new technologies to make life better.
Sometimes the solutions are what scientists call “elegant.” That’s when a problem lends itself to a simple, straightforward solution.
Unfortunately, life tends to be complicated, and sometimes we fail to predict the full impact of our solutions. Other times, we may find that people come up with workarounds — or sometimes, even improvements — that exacerbate the original problem.
I learned recently about an example of this that made me want to laugh and cry at the same time.
It starts with the fact that our automobiles (until the recent introduction of all-electric vehicles, or EVs) use internal combustion engines that burn gasoline and produce exhaust containing a variety of pollutants.
Among the byproducts of combustion are dangerous gases such as carbon monoxide, volatile organic compounds (VOCs), and nitrogen oxides that contribute to smog and acid rain and can cause respiratory problems.
Of even more concern is “particulate matter” — especially the very tiny particles that can be breathed deep into our lungs and even enter our bloodstreams, as well as wash into the soil and pollute the water supply.
Ingenious engineers, however, have developed the “catalytic converters” now required in all cars, that help convert the harmful gases into harmless (well, less harmful) ones using precious metals to facilitate chemical reactions that break down the pollutants.
Diesel trucks, as well as many European cars and some luxury U.S. models, also utilize particulate filters that can remove a substantial amount of the particulate matter from exhaust.
Due to the gradually stricter regulation of auto pollution from the federal government (and certain states), and thanks to these technologies, we have made great progress in reducing the harms of internal combustion engines. Up to 90% of harmful gases, for example, are converted into safer forms.
Unfortunately, researchers and engineers have more recently become aware of another, possibly even worse, source of dangerous pollutants from our cars: tires and brakes.
It turns out that the wearing down of tires and brake pads over time produces — you guessed it — fine particulate matter!
When you think about it, this should have been rather obvious. After all, every time we replace tires because the tread has worn down, we know on some level that all that rubber has not only met the road, but probably rubbed off on the asphalt as well.
What seems to have surprised researchers is how much of that rubber (often a synthetic kind that includes carcinogens) turns into ultrafine particles — the most dangerous kind to human health — and how difficult it is to prevent these from entering the air, soil, water and our lungs.
Add to that the copper, zinc, iron and other materials used in brakes that enter the air as brake dust. These metallic particles are potentially more toxic than tailpipe emissions, but are more difficult to reduce or remove.
So, what about those EVs that we all hope will improve our ozone layer and reduce human-influenced climate change? They produce no tailpipe emissions at all, so they do achieve an incremental benefit over gas-powered cars with catalytic converters.
But they accomplish this by utilizing clean batteries for power. And guess what? Those batteries are extremely heavy. And the more drivers demand high mileage from their EVs and turn to larger vehicles like electric trucks, the larger those batteries need to be.
In fact, such EVs are at least 50% heavier than gas-powered cars. And the heavier the car — you guessed it — the more wear and tear on the tires and brakes, and the more particulate matter they produce!
Yes, it seems our electric solution to tailpipe emissions (which had already been much-reduced) is likely to exacerbate the potentially larger and more dangerous pollution problem that all cars retain in the form of worn-down tires and brakes.
I’m sure this is not the end of the story. Creative engineers are already hard at work experimenting with tires made from natural and sustainable crops (a type of dandelion is showing promise).
And who knows? Maybe cars will one day be required to carry a vacuum that sucks up the particles from the road as we drive.
We humans are pretty inventive. We may cause all kinds of ills on this planet of ours, but some of us always have that inner drive to make things better. Eventually. We hope.
