Whedoes Tidust go?

Ok, so we've got ourselves a nice Island 3, with a million people in
it.

Distances are too great to walk or bike everywhere and as we
discussed in a thread about a year ago, we're going to need some
type of personal transportation.

If we you our existing model, and we have some type of car traveling
on a road, they'll need tires. Those tires wear out after a while
and need to be replaced.

Handling the scrap tires should be easy enough, but what happens to
the thread of the tire as it wears down? Does it adhere to the road
or does it become dust and blow in the wind?

If the latter, aren't we going to have a big problem in a closed
environment?

How about other types of such benign pollution that is easy for our
Earth environment to absorb but will pose a problem for our much
smaller Habitat system.

Outdoor barbecues?
Cow farts?
Degrading biomatter?
Sythetic fiber fumes?
Teflon coating on your cookware?
Prescription drugs in human waste being recycled?

You get the idea.

Any suggestions?

TangoMan