Disinfection is not always good for health. According to a Belgian study swimming in chlorinated pools may cause asthma and respiratory allergies like hay fever.
Researchers from the Catholic University of Louvain in Brussels, Belgium, found that teenagers who spent more than 100 hours swimming in chlorinated pools were up to six times more at risk of having asthma than other teens.
"The impact of these chemicals on the respiratory health of children and adolescents appears to be much more important -- at least by a factor of five -- than that associated with secondhand smoke," toxicology professor Alfred Bernard stated.
In the study, Bernard and his colleagues compared the health of 733 teenagers aged 13 to 18 who swam in chlorinated pools for various amounts of time with that of 114 teenagers who swam mostly in pools sanitized with a mix of copper and silver.
Among children and teens who swam in chlorinated pools for between 100-500 hours, 22 children out of 369, or six percent, had current asthma, compared with only 2 of 144, or 1.8 percent, of those who had spent less than 100 hours in chlorinated pools.
The risk of asthma and allergy was not influenced by swimming in copper-silver sanitized pools and children without allergic tendencies were not at increased risk of developing allergies, reported by Reuters.