Documentation re: The Dangers of Swimming in a Chlorinated Pool
After 40 minutes of swimming, people in a study showed a rise in markers of DNA damage that can lead to cancer.
Swimming in a chlorinated pool may increase your risk of developing cancer, suggest a new suite of studies, which identified more than 100 chemical byproducts in pools that use chlorine as a disinfectant. The work is too preliminary to suggest that people should stop swimming, said Manolis Kogevinas, an epidemiologist at the Center for Research in Environmental Epidemiology in Barcelona. Still, Kogevinas said, the findings suggest that people need to work harder to reduce everyone’s exposure to chlorine.
After 40 minutes of swimming, the study found, people showed a large rise in markers of DNA damage that can lead to cancer. Concentrations of four of the most common byproducts were seven times higher after people swam. Alfred Bernard, a toxicologist at the Catholic University of Louvain in Brussels, Belgium…chlorine byproducts are a major risk factor for rising rates of asthma, airway irritation and allergic diseases, especially during windows of sensitivity in babies and young children.
“We have good evidence that you have to be careful with these chemicals,” Bernard said. “Maybe chlorine is not the best choice for disinfecting swimming pools.”
Negative Health Effects of Chlorine
Studies in Belgium have related development of deadly malignant melanoma to consumption of chlorinated water.28 Drinking and swimming in chlorinated water can cause melanoma.29,30,31 Sodium hypochlorite, used in chlorination of water for swimming pools, is mutagenic in the Ames test and other mutagenicity tests.32,33 Redheads and blonds are disproportionately melanoma-prone; their skin contains a relative excess of pheomelanins34 compared to darker people.35 Franz Rampen of the Netherlands reports worldwide pollution of rivers and oceans and chlorination of swimming pool water have led to an increase in melanoma.36,37
Long-term risks of consuming chlorinated water include excessive free radical formation, which accelerates aging, increases vulnerability to genetic mutation and cancer development, hinders cholesterol metabolism, and promotes hardening of arteries.
Excess free radicals created by chlorinated water also generate dangerous toxins in the body. These have been directly linked to liver malfunction, weakening of the immune system and pre-arteriosclerotic changes in arteries. Excessive free radicals have been linked also to alterations of cellular DNA.42 Chlorine also destroys antioxidant vitamin E,2 which is needed to counteract excess oxysterols/free radicals for cardiac and anti-cancer protection.
A study in the late 1970s found that chlorinated water appears to increase the risk of gastrointestinal cancer over a person’s lifetime by 50 to 100 percent. This study analyzed thousands of cancer deaths in North Carolina, Illinois, Wisconsin and Louisiana. Risk of such cancers results from use of water containing chlorine at or below the Environmental Protection Agency standard and “is going to make the E.P.A. standard look ridiculous,” stated Robert Harris, lead scientist in the study.43
A later meta-analysis44 found chlorinated water is associated each year in America with about 4,200 cases of bladder cancer and 6,500 cases of rectal cancer. Chlorine is estimated to account for nine percent of bladder cancer cases and 18 percent of rectal cancers.
Dr. Weil 2009
Chlorine used to disinfect swimming pools is widely recognized as a health hazard. New research suggests that children who swim frequently in chlorinated pools may have increased risks of developing allergies or asthma. Among adults exposure to chlorine in swimming pools has been linked with other health problems including bladder and rectal cancer and, possibly, an increased risk for coronary heart disease.
The Belgian researchers also found that the risks of hay fever and other allergies more than doubled with significant exposure to chlorinated pools. The study was published in the online issue of Pediatrics on Sept. 14, 2009