Health officials say they found fecal bacteria in more than half of the water samples taken from Atlanta-area public swimming pools last summer.
Investigators found the gut bacteria in 58 percent of the samples taken from about 150 pools in Cobb, DeKalb, Fulton and Gwinnett counties. They were gathered from municipal pools or pools at water parks, apartment complexes and clubs.
Municipal pools — where young children in diapers are common — were worst, with 70 percent of samples tainted.
No illness outbreaks were tied to the pools.
Proper chlorine and pH levels should kill bacteria. But health officials advise people to shower before the pool, and not swim if they have diarrhea.
The Centers for Disease Control and Prevention released the study Thursday.