BROMATE, CHLORITE, CHLORATE, HALOACETIC ACIDS (HAAS), AND TRIHALOMETHANES (THMS) DETERMINATION IN INDOOR SWIMMING POOLS

People attending indoor swimming pools are exposed to Disinfection By-Products (DBPs) by ingestion and also by dermal contact and/or inhalation, as a consequence of water disinfection treatments with chlorine and related compounds. The occurrence of Trihalomethanes (THMs) in pool waters has been well documented while information about the presence of other DBPs (bromate, chlorite, chlorate, haloacetic acids) in indoor swimming pools is very limited and needed to be further investigated as some of these substances are potentially dangerous for human health. The aim of this study was to investigate the presence of bromate, chlorite, chlorate, halogenated acetic acids and THMs in some Italian indoor swimming pools in order to evaluate the potential exposure in competitive swimmers and pool attendants. In this study, starting from February 2005 in the Emilia Romagna Region, in the North of Italy, 24 indoor swimming pools were investigated. THMs were evaluated with a standardized method involving the head-space gas chromatographic technique while HAAs, bromate, chlorite, chlorate were detected by ion chromatography with mass spectrophotometry. THMs, bromates, chlorates and chlorites and HAAs were investigated not only in pool waters but also in water feed. THMs were present in all the pool water samples (41.4±30.0 μg/L), while they were present above the detection limit in only 50% of the water supply: in the latter, the average concentrations of THMs were generally low (4.8±1.5 μg/L), a consequence of the treatments for drinking water disinfection with chlorine dioxide, widespread in Italy. Bromate has never been detected in water supply samples, while it was observed only in 3 samples of pool water (range: 10-48 μg/L). Chlorite were present in 15 samples of water supply and only in one sample of pool water. Chlorates have been detected in high concentrations in pool waters, with a mean value of 4717±5758 μg/L. Regarding to haloacetic acids, the levels ranged from 11 to 403 μg/L, with a mean value of 170±122 μg/L. In people attending swimming pools, the health risks from exposures to THMs, bromate, chlorite and haloacetic acids can be considered to be small. However, the high levels of chlorates sometimes observed should be further evaluated for their potential effects even if, at the moment, there is no epidemiological evidences and/or associations between environmental exposure to these compounds and human health.