That's the intended message of a study of Italian tollbooth workers. The study found that the workers had poorer quality sperm compared to a control group of nearby, non-tollbooth workers. The study's authors say that exposure to traffic pollution is to blame.
But New Scientist notes that any job with a lot of sitting can build up heat to pelvic area, a no-no for those in search of the best and most sperm. Perhaps the next study in the traffic and male fertility field should examine the effect of wearing a kilt while Rollerblading to work. Or establish once and for all if driving a Porsche or other incredibly expensive sports car really does increase the size and functionality of male genitalia or merely the owner's perception of them.