Studies show that only about 40 percent of health care workers in the U.S. wash their hands as often as they should. Rob Carr/AP hide caption

itoggle caption Rob Carr/AP

According to a study of four jurisdictions that have banned the use of hand-held devices while driving, the laws have not reduced accident rates. iStockphoto.com hide caption

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A woman receives treatment in a U.S.-run emergency clinic in Port-au-Prince. John W. Poole/NPR hide caption

itoggle caption John W. Poole/NPR

According to a new study, people who smoke menthol cigarettes seem to have more difficulty quitting than those who smoke regular cigarettes. iStockphoto.com hide caption

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