Childhood asthma is on the rise - and researchers believe it could have something to do with the chlorine in swimming pools. The likeliest suspect is nitrogen trichloride, a byproduct of the chlorine, which is a powerful irritant.
Belgian researchers found high levels of lung-specific proteins - a marker of lung permeability - in children who regularly visited indoor swimming pools, and had done so since early childhood.
These proteins suggest that the lung's epithelial barrier was being constantly and chronically disrupted and which, in turn, was allowing allergens to enter the lungs.
It's an early indicator and more research is needed, say the researchers. Nonetheless, people who run swimming pools should already be looking at non-chlorine-based disinfectants.
In the meantime, try to search out these swimming pools for yourself.
(Source: Occupational Environmental Medicine, 2003; 60: 385-94).