Occupational exposure in Italian swimming pools and self-reported health conditions

In indoor swimming pools both chemical substances in water and air and microclimate parameters influence health status and well-being of subjects employed in these environments. In order to investigate on the possible detrimental impacts of occupational exposure for trainers, lifeguards and facility operators 20 indoor swimming pools in Emilia Romagna have been visited in 2007 and 133 workers were enrolled in the study.Microclimate parameters (dry and radiant air temperature, air speed, relative humidity, illumination levels) were measured by a multi-data logger (BABUC A-LSI Lastem) equipped by a software (InfoGAP) aimed to calculate microclimate indices for moderate environments, taking into account personal clothing. Disinfection By Products (DBPs) such as trihalomethanes (THMs) and residual combined chlorine were evaluated in pool water: THMs were analysed in indoor air and in alveolar air samples collected from 115 workers. Head space gaschromatography was used for THMs in water samples, while THMs both in indoor air and alveolar air samples were analysed by direct injection. Information about personal data and job description was collected. Self-reported health conditions were recorded by a questionnaire: upper respiratory symptoms (runny nose, nasal obstruction, voice loss, etc), lower respiratory symptoms (wheezing, asthma, etc), ocular symptoms (itchy, red and watering eyes) and ever presence of fungal diseases, warts and dermal irritative symptoms were registered, together with self-reported information about dermal comfort/discomfort.On the whole, microclimate parameters are within the range of values suggested by the Italian guidelines for indoor swimming pools. In 19 environments (95%) illumination levels were in agreement with the above guidelines (≥150 lux); similarly, air speed values and relative humidity levels were adequate (≤0.1 m/s and ≤70% respectively) for 14 (70%) and 13 (65%) swimming pools. 14 swimming pools (70%) showed dry air temperature values lower than water temperature, and so associated with a thermal discomfort condition. The Predicted Mean Vote (PMV) is a thermal index which scores the comfort/discomfort level for workers, taking into account dry air temperature, relative humidity and air speed levels. The values showed a generally acceptable thermal condition shifted towards a warm sensation. The most prevalent health symptoms were nasal obstruction (21,1%), voice loss (17.3%) and mucosal irritative symptoms (15.8%), followed by red eyes (13.5%), itchy eyes (12.8%) and watery eyes (6%). THMs in indoor air (range: 1.7-187.5 mcg/m3) were highly correlated with THMs in alveolar air samples (range: 1.0-123 mcg/m3) (r = 0.68; P = 0.001). Chloroform, the most prevalent compound, and dichloro bromo methane (DCBM) were detected in all indoor air samples, while they were present in 98.3% and 82.6% of alveolar air samples respectively. Swimming pools have been splitted according to the suggested Italian guideline for combined chlorine in water (≤0.4 mg/l) assumed as the source of trichloramine, volatile irritative compound in indoor air. Subjects working in environments (15 swimming pools) where combined chlorine levels were above 0.4 mg/l experienced more symptoms of nasal obstruction and ocular irritative symptoms compared to those employed in swimming pools with lower levels in water.