Airborne trichloramine (NCl3) levels and self-reported health symptoms in indoor swimming pool workers: dose-response relationships.

The hypothesis that attendance at indoor chlorinated swimming pool is a risk factor for irritative ocular and respiratorysymptoms and bronchial asthma is well known in literature, although epidemiological evidence ìs stili inconclusive. The aimof this study was to evaluate thè association between airborne trichloramine (NCI3) levels and irritative symptoms in swimmingpool employees in order to obtain detailed data regarding dose-response relationships and to ìdentìfy thè airborne NCI3exposure level, if any, without health effects. A total of 20 indoor swimming poois in thè Emilia Romagna region of Italy wereincluded in thè study. Information about thè health status of 128 employees was collected using a self-administeredquestìonnaire. Exposure to airborne NCI3 was evaluated in indoor swimming poois by a modified DPD/KI method. The resultsof thè study evidenced a mean value of airborne NCI3 of 0.65 ± 0.20 mg/m3 (ranging from 0.20 to T.02 mg/m3). Both ocular andupper respiratory symptoms, in particular red eyes, runny nose, voice loss and cold symptoms, were declared more frequentlyby lifeguards and trainers when compared with employees working in other areas of thè facility (office, cafe, and so on). Poolattendants exposed to airborne NCI3 levels of > 0.5 mg/m3 experlenced higher risks for runny nose (OR: 2.91; 95%CI: 1.22-6.93) red eyes (OR: 3.16; 95% CI: 1.46-6.82), voice loss (OR: 3.56; 95% CI: 1.60-7.95) and itchy eyes (OR: 2.23; 95%CI: 1.04-4.78) than other employees. Moreover, red eyes, itchy eyes, runny nose and voice loss are related to airborne NCI3levels, with strong dose-response relationships. In conclusion, this study shows that lifeguards and trainers experience ocularand respiratory irritative symptoms more frequently than employees not exposed. irritative symptoms become significantstarting from airborne NCI3 levels of > 0.5 mg/m3, confìrming that thè WHO-recommended value can be consìdered protectivein occupational exposure to airborne NCI3 in indoor swimming poois