Douglas Main, Popular Science May 20, 2014, 12:40 PM Washing fluid can carry the bacterium responsible for Legionnaires' disease. That which cleans your windshield is not exactly clean itself: A new study found that windshield washing fluid can harbor the bacteria that causes Legionnaires' disease, a severe type of pneumonia that hospitalizes as many as 18,000 Americans every year. Scientists already knew that there was a link between Legionnaires' and riding in automobiles, but didn't know why--and the fluid may be the reason. In the study, presented today (May 19) at the annual meeting of the American Society for Microbiology,...