Almost half of the injuries – which were all preventable – occurred in children and teenagers. More than a third of the injuries occurred at a home pool, and the most common injury was poisoning.
“Chemicals are added to the water in pools to stop germs from spreading. But they need to be handled and stored safely to avoid serious injuries,” said Michele Hlavsa, chief of CDC’s Healthy Swimming Program. Injuries occurred in the way the chemicals were mixed or prepared.
Poisoning from orally ingesting chemicals or from inhaling their vapors was the most common diagnosis, occurring in 92 percent of participants. Chemical burns, infection of the eye, and dermatitis were other diagnoses reported.
In the report, investigators separately evaluated a group of eight children who swam in an indoor hotel swimming pool in 2013. They developed rash, headache, cough, sore throat, and vomiting for up to seven hours after leaving the pool. They were diagnosed in the ER with chemical burns.
Chlorine levels in the pool were found to be between 15 and 30 ppm, while the limit is 5 ppm. The pH was 9, but the state maximum level is 8.
If pool water doesn’t contain enough chemicals, swimmers are at risk of infection, however. Some germs are “very tolerant to chlorine,” the CDC notes, and only recently have begun to cause human disease. It can take up to several days for chlorine to kill these resistant germs, and swallowing just a little water that contains the germs can cause illness.
One germ that is showing more infections in swimmers is Cryptosporidium, which can stay alive for days even in well-maintained pools, according to the agency. Cryptosporidium is now the leading cause of swimming-pool outbreaks of diarrheal illness in the United States, with an increase in cases of more than 200 percent between 2004 to 2008, according to CDC.
Illness from improper pool chemicals can occur in places other than swimming pools, such as hot tubs, water parks, or water play areas. In indoor pools, chemicals in the water can evaporate and cause problems with indoor air quality as well, the CDC reports. .
Many public pools may not contain “healthy” recommended levels of chlorine, a 2010 study found. In fact, one in eight public pools was closed immediately because of serious code violations, such as improper chlorine levels, the study found.
The CDC recommends states and local authorities regularly update codes for public treated recreational water venues. It has also begun a national consortium of public health and aquatic officials to develop “model guidance” on state and local regulations for treated recreational water.
To help prevent pool-related injuries, the CDC recommends residential and public pool owners follow certain steps to prevent pool chemical injuries:
• Read and follow directions on product labels.
• Wear appropriate safety equipment, such as goggles and masks, as directed, when handling pool chemicals.
• Secure pool chemicals to protect people and animals from getting into them. • Keep young children away from the pool when handling chemicals.
• Don’t ever mix different pool chemicals with each other, especially chlorine products with acid.
• Pre-dissolve pool chemicals only when the product label instructs you to.
• Add pool chemical to water; don’t ever add water to pool chemicals.