There are an endless number of gross and harmless things which I don't want to sprinkle on my food.

It's actually a good question, and I'm disappointed to read middlebrow dismissal of it.

As long as we want to go fast, there will be some brake dust in the air. Brake pads can be made out of a variety of materials, and we want to use the ones which are least harmful to our lungs and other organs.

That takes research, not emotional appeals to disgust (from the Latin, meaning "bad to eat").