July 17, 2006

Study links asthma with indoor swimming pools

LONDON (Reuters) - Rising cases of asthma in European
children could be partly due to indoor swimming pools, Belgian
scientists said on Tuesday.

They believe exposure to chlorine bi-products, both in the
air and the water, could be a factor.

"The prevalence of childhood asthma and the number of
indoor chlorinated swimming pools in Europe are linked through
associations that are geographically consistent and independent
of climate, altitude and the socioeconomic status of the
country," said Professor Alfred Bernard, of the Catholic
University of Louvain in Brussels.

Researchers compared the rates of asthma in 13 and
14-year-old children in 21 European countries and the number of
chlorinated swimming pools per 100,000 people.

They found that after taking into account other factors
such as climate, childhood asthma and wheeze increased by 2-3
percent for every indoor swimming pool, according the research
published in the journal Occupational and Environmental

Asthma is one of the most common chronic diseases and is
increasing fast. The number of cases of the disease, which
affects the small tubes that carry air in and out of the lungs,
has risen by more than 50 percent in developed countries in the
last 25 years.

Between 100 and 150 million people worldwide suffer from
asthma, according to the World Health Organization. About
180,000 die from it each year.

Risk factors for the illness, which can be controlled but
not cured, include early exposure to allergens such as domestic
mites, a family history of the illness and exposure to tobacco

Bernard and his team found that the rate of wheezing rose
by 3.4 percent and asthma by 2.7 percent for every additional
indoor chlorinated swimming pool.

The numbers of indoor swimming pools ranged from one for
every 50,000 inhabitants in Western Europe to one for every
300,000 people in Eastern Europe.

The researchers called for more study of the impact of
chlorinated swimming pools and asthma risk and for better
ventilation of indoor pools.