May 22, 2010 -- Before plunging into your local public pool, you might want to stop and think about what you might be plunging into. The pool might not be as sanitary as it should be, according to a report by the Centers for Disease Control and Prevention. Researchers found that one out of eight pools had to be closed immediately for serious code violations.
The report, published in the CDC's Morbidity and Mortality Weekly Report this week, analyzed data from more than 121,000 routine pool inspections in 13 states in 2008. More than 12 percent of the inspections found serious violations that caused the pools to close immediately.
Violations included an inadequate level of chlorine in the pool and an improper pH level of the water, both of which can lead to transmitting disease-causing germs.
The researchers examined data from inspections of pools in child care facilities, residential complexes, hotels and motels, kiddie/wading pools and interactive fountains.
"Pools in child care settings had the highest percentage of inspections that resulted in immediate closures," said Michele Hlavsa, an epidemiologist at the CDC and head of its Healthy Swimming Program.
Hlavsa's team also found that kiddie/wading pools and interactive fountains had the highest percentage of disinfectant violations.
The fact that around 13 percent of pool inspections violated safety standards didn't come as a surprise to at least one infectious disease specialist.
"It's not easy to keep pools, especially outdoor pools, within compliance," said Dr. William Schaffner, chairman of the Department of Preventive Medicine at Vanderbilt University. "They must be checked frequently."
Pool Water May Harbor Germs
That's because there's a potentially huge risk of coming into contact with bugs that cause intestinal infections, such as shigella and norovirus.
Another microorganism often associated with pool water is pseudomonas, Schaffner said. A pseudomonas infection doesn't typically cause illness, but people who contract it can develop pustules on their skin.
Hlavsa said she hoped this data would open the eyes of anyone who swims in recreational pools. While it's clear that more inspections are needed, much of the onus is on the public.
"Pool inspections are vital to helping state and local government pool programs keep swimmers healthy and safe, but pool inspectors can't be at every pool every day," Hlavsa said. "It's important for people to play an active role in protecting their own health when they swim."
She encourages people to ask pool operators what the pH level of the water is, and to test the water themselves by using pH test strips that are available for free through the Healthy Pools website.
The water should have a level between 7.2 and 7.8.
The CDC recommends that people avoid swimming if they have diarrhea, avoid swallowing pool water, shower with soap before getting into the pool, and wash their hands after getting out.
It's especially important to pay attention to children's hygiene. Wading pools and interactive fountains are harder to keep disinfected because of shallow water and a buildup of dirt. Hlavsa warned that while kids love to play in these areas, any germs they come into contact with will make them sicker than adults.
And while small children are very susceptible to contracting intestinal infections, their dirty diapers also help to spread them.
"Parents have to be very observant. They need to change their children's diapers away from the side of the pool and also check their children's bottoms after they go swimming," Schaffner said.
Despite the inspection findings, experts stressed that there's no need for alarm, and no need to keep away from public pools.
Most Pools Still Meet Guidelines
"Swimming is a great physical activity, but people just need to think a little more and take more active roles in making sure it's healthy, too," Hlavsa said.
"While they found that about 12 percent of pools didn't pass inspection, there were still about 88 percent that did meet the criteria, and that's significant," Schaffner said.