Swimming teachers and other people who spend a lot of time near chlorinated pools face an increased risk of respiratory hazards, Dutch researchers report.

Chlorine reacts with urine and sweat to create byproducts that can irritate the respiratory tract, said Dr. Jose Jacobs of the University of Utrecht in the Netherlands and colleagues in a report in the European Respiratory Journal.

The research team surveyed 624 swimming pool employees and took air samples at six swimming pools. They measured trichloramine levels at all 38 pools included in the study to estimate long-term exposure among employees. Trichloramines are the most volatile type of chloramine, and are known to irritate the eyes and upper respiratory tract.

Swimming instructors were 2.4 times more likely to suffer frequent attacks of sinusitis or sore throat when compared to pool workers with the least exposure to trichloramines, such as catering employees or receptionists, and faced a 3.4-fold greater risk of chronic cold, the researchers found.

Employees with high levels of exposure were at greater risk of a number of other respiratory symptoms compared to the general Dutch population, ranging from a 40 percent increased risk for tightness of the chest to a more than sevenfold greater likelihood of suffering breathlessness while walking with a person of the same age.

People who reported excessive humidity or inadequate ventilation at work were also more likely to report breathing problems.

(Xinhua News Agency April 13, 2007)