A national survey of more than 5,000 households found that one in three has a gun, and offers more evidence that many gun owners are not storing their weapons safely.

At least one gun is kept loaded and unlocked in about 20 percent of households with firearms, according to the survey published this month in the Archives of Pediatrics and Adolescent Medicine.

The researchers discovered that in 11 percent of homes with both a firearm and a child younger than 18, a gun is stored loaded and unlocked. By comparison, 30 percent of households without children store their weapons in this manner.

Dr. Gail Stennies, the paper's lead author, said these figures should underscore the potential risk for children of injuries from guns -- even if they do not live in a home with guns.