Parents worldwide are doing little to protect their children from exposure to secondhand smoke, according to a study by researchers at the Johns Hopkins Bloomberg School of Public Health.

Recent research on the dangers of secondhand smoke could help clear the air about the value of no-smoking laws governing bars and eateries.

Tens of thousands of Americans die each year from secondhand tobacco smoke, according to a 2006 report by the U.S. Surgeon General. While the health risks associated with indoor secondhand smoke are well documented, little research has been done on exposure to toxic tobacco fumes outdoors.