When I read this about the diesel smoke, I thought about you.
If there's anyone who knows about diesel smoke it's truck drivers, and I'll bet they weren't even considered in this "study".
Truck drivers are never considered, except as red-necked, CB radio using', waitress pinchin', road hoggin', pollutin', neanderthals. :)
Other than that, we're the salt of the earth. :)
It's funny, most numb skulls don't know that everything they buy has at something during it's life, it or one some of it's components have been transported by truck.