AIRBORNE TRICHLORAMINE (NCl3) EXPOSURE IN INDOOR SWIMMING POOLS AND PREVALENCE OF SELF-REPORTED RESPIRATORY AND OCULAR SYMPTOMS IN OCCUPATIONALLY EXPOSED SUBJECTS

Background and Aims: The aim of this cross-sectional study was to investigate the association between airborne NCl3 exposure in indoor swimming pools and the prevalence of self-reported respiratory and ocular symptoms in occupationally exposed subjects.Methods: Twenty indoor swimming pools in the Emilia-Romagna region of Italy were included in the study. Information about the health status of 128 employees was collected using a self-administered questionnaire. Exposure to airborne NCl3 was evaluated in indoor swimming pools by a modified DPD/KI method. Results: The airborne NCl3 levels ranged from 204 to 1020 μg/m3 with a mean value of 648.7 ± 201.4 μg/m3. More than 50% of the swimming pools showed airborne NCl3 levels higher than 500 μg/m3 recommended WHO guidelines). Both ocular and upper respiratory symptoms were very frequent in the 128 employees: red eyes, runny nose, voice loss and cold symptoms were declared more frequently by pool attendants (lifeguards and trainers) when compared with employees working in other areas of the facility (office, cafe, etc.). Pool attendants exposed to airborne NCl3 levels higher than 500 μg/m3 experienced higher risks for runny nose (OR: 2.9; 95% CI: 1.22-6.94), red eyes (OR: 3.2; 95% CI: 1.5-6.8), voice loss (OR: 3.6; 95% CI: 1.6-8.0), itchy eyes (OR: 2.2; 95% CI: 1.0-4.8) than other employees. When high levels of airborne NCl3 were taken into account (airborne NCl3 levels ≥ 800 μg/m3 vs. < 800 μg/m3) ocular and respiratory symptoms became much more evident, with higher risks (as ORs) in exposed subjects (lifeguards and trainers) compared with other employees. Conclusions: This study confirms that lifeguards and trainers are at risk for respiratory and ocular irritative symptoms more than other employees in indoor swimming pools, in particular in presence of high airborne NCl3 levels.