=v= There's an interesting story in today's _L.A._Times_:
Studies are finding a cause-and-effect relationship between air
that's heavy in particulates and heart attacks. They're even
starting to suspect that air pollution kills more people through
heart attacks than through lung disease.
=v= The main sources of particulates mentioned in the article
are cars and trucks that use diesel fuel, industry, and "dust."
It says "windborne dust" at one point, and "road dust" later.
I take "road dust" to mean yet more car-originated pollution;
one particularly bad component of this is tire dust, as was
brought to light in 1995 by _Rachel's_weekly_:
Particulates are also implicated in cancer.
=v= The environmental justice movement has been focusing on
diesel fuel for a few years now, because the folks exposed most
heavily are disproportionately people of color. We all get a
dose, though, and we should all work on the problem together.