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Excerpted from Medscape Medical News, July 2006
Swimming in indoor pools is associated with increasing risk of
asthma, according to the results of a study published in
Occupational and Environmental Medicine. (a journal of the
British Medical Society).
"Regular attendance at chlorinated pools by young children is
associated with an exposure dependent increase in lung
epithelium permeability and increase in the risk of developing
asthma, especially in association with other risk factors,"
write Alfred Bernard, from the Catholic University of Louvain in
Brussels, Belgium, and colleagues. The trigger seems to be
trichloramine, or nitrogen trichloride, a highly concentrated
volatile by-product of chlorination, which is readily inhaled
and generated during contact between chlorine and urine, sweat,
or other organic matter. To evaluate the immediate effects of
trichloramine, Dr. Bernard's group also analyzed sera from 16
children, aged 5 to 14 years, and 13 adults, aged 26 to 47
years, before and after swimming in an indoor pool. The group
also assessed the prevalence of childhood asthma, using data
from a survey done between 1996 and 1999 of 1,881 children aged
7 to 14 years. In children and adults attending an indoor
pool, serum SP-A and SP-B increased significantly after one hour
at poolside without swimming. Cumulated pool attendance
significantly correlated with exercise-induced
bronchoconstriction test and total asthma prevalence. For
children who swam the most frequently, lung damage was
equivalent to that found in regular smokers. "We therefore
postulate that the increasing exposure of children to
chlorination products in indoor pools might be an important
cause of the rising incidence of childhood asthma and allergic
diseases in industrialized countries," the authors write, while
recommending further epidemiological studies. "The question
needs to be raised as to whether it would not be prudent in the
future to move towards non-chlorine based disinfectants, or at
least to reinforce water and air quality control in indoor pools
in order to minimize exposure to these reactive chemicals."
Occup Environ Med. 2003;60:385-394 |
