The incidence of asthma and wheezing among children can rise significantly if they use an indoor swimming pool, according to a European study published on Monday.
Investigators in Belgium analysed data from 190 000 youngsters
aged 13-14 in 21 countries, who were asked to give details about
any breathing problems, hay fever and atopic eczema.
The researchers found a preponderance of asthma and wheezing in
towns and cities where there was a high density of indoor pools.
Rates of asthma and wheezing rose by 2.73 and 3.39 percent
respectively for every additional indoor swimming pool. Prevalence
of these problems was higher in Western Europe than in Eastern
Europe, mirroring the higher number of pools in the Western part of
The study appears online in Occupational and Environmental
Medicine, published by the British Medical Association (BMA).
Nitrogen trichloride to blame
Chief author Alfred Bernard, a professor of public health at the
Catholic University of Louvain, Brussels, believes the cause lies
with nitrogen trichloride, a gassy, easily inhalable irritant.
This chemical, also called trichloramine, is released when
chlorinated water reacts with urine, sweat or other organic matter
brought by swimmers.
Bernard notes that more and more swimming pools have been built
in past decades and, thanks to their increasingly lavish equipment,
such as wave machines and slides, children spend more and more time
"This increasing attendance of swimming pools by children has in
turn led to substantial changes in the swimming pool environment,
such as higher water temperatures, increased bathing loads, and
installation of recreational equipment," he says.
"All these changes have contributed to raising the levels of
chlorination by-products in pool air, especially as, at the same
time, energy conservation programmes reducing ventilation were
implemented to face the rising cost of energy."
Research carried out by Bernard in British pools in 2003 found
high levels of trichloramine-triggered proteins in the blood of
young swimmers and even among parents who had sat by the poolside
and not swum.
Asthma getting worse globally
Asthma has been identified as a worsening health problem around
the world, but the suspected causes for it are various.
The finger of suspicion is pointed at obesity, genetic
predisposition, smoking, low birth weight, air pollution, household
dust mites and other allergens. Strong emotions and the weather can
exacerbate the condition. – (Sapa-AFP)
Enviro health Centre