Indoor pools tied to asthma

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 continent.

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 there.

"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)

Read more:
Asthma Centre
Enviro health Centre

July 2006