Chlorine on its own won’t make your eyes red. But when it reacts with human urine it forms chemical compounds that will.
As the Northern Hemisphere summer gets into full swing, Quartz has a disturbing report on the cleanliness of the public swimming pool.
The research on the red-eye condition was carried out for the Healthy Swimming Program, a collaboration between the US Centers for Disease Control, the Water Quality and Health Council, and the National Swimming Pool Foundation.
Red eyes may be the least of the problems, however. The research found that chlorine’s reaction with two chemicals in urine — urea and uric acid — creates two poisonous gases that can hurt people’s lungs, hearts, and central nervous systems.
The program found that chlorine itself might not be the answer to keeping pools clean, either.
It found that the chemical does not kill some of the most insidious types of bacteria fast enough to prevent infections – the bacteria Cryptosporidium can live in chlorinated pools for days.
In spite of widespread chlorine use, outbreaks of recreational water illnesses (RWIs) have climbed in the past decade, says the CDC. During that time, more than 20,000 people have picked up diarrheal illnesses from water they swallowed in US swimming pools, water parks, and other disinfected swimming venues.