Risk of any type of stroke was three times higher in severe dozers than nondozers.

WSJ: Even Outdoors, Second-Hand Smoke Affects Non-Smokers

How about the tractor company that profits from selling oil companies bull dozers?

FORBES: Socially Sensitive Stupidity

Subjects included 921 nondozers, 981 moderate dozers and 186 severe dozers.

WSJ: Even Outdoors, Second-Hand Smoke Affects Non-Smokers