715 Occupational exposure to trichloramine and trihalomethanes adverse health effects in rehabilitation swimming pools

Introduction Studies have shown that employees and visitors at indoor swimming pool facilities are experiencing symptoms in the nose and throat, eye irritation and, in some cases, asthma. Due to chlorination, byproduct such as trichloramine and trihalomethanes can be present in indoor swimming pool air. This exposure has not been described in rehabilitation swimming pools that normally consists of smaller facilities and use warmer water compared to ordinary swimming pools. Methods The occupational exposure of trichloramine and trihalomethanes in air has been studied at ten Swedish indoor swimming pool facilities. The study has also included the prevalence of ocular symptoms and symptoms and effects on the upper and lower respiratory tract. Nitrogen oxide (NO) in exhaled air has been investigated as a measure of early respiratory tract inflammation. Results The average trichloramine concentration for personal measurements (n=17) was 23 µg/m 3 , varying between 1 and 76 µg/m 3 . Corresponding stationary measurements (n=27) performed at the pool side showed an average concentration of 30 µg/m 3 , varying between 1 and 140 µg/m 3 . A WHO reference value for trichloramine, based on stationary measurements, is set to 500 µg/m 3 . The levels of trihalomethanes for both personal (n=20) and stationary (n=35) measurements were less than 1% of the Swedish OEL for chloroform. Measurements of NO in exhaled air showed a change during shift when exposed (n=23) and controls (n=50) were compared. Discussion Both personal and stationary measurements showed low levels of trichloramine and trihalomethanes. When comparing exposed and controls during shift, a difference of NO in exhaled air was noted.