title: Effects of medium-pressure UV lamps radiation on water quality in a chlorinated indoor swimming pool.
abstract: The aim of our study was to determine the impact of medium-pressure UV lamps radiation on water quality in a chlorinated indoor swimming pool. An indoor swimming pool was equipped with two medium-pressure UV lamps. We collected eight samples of water daily over a four-weeks period and measured total and free chlorine, pH, water temperature, bacteriological parameters, total organic carbon and trihalomethanes. During the first week, which served as control, medium-pressure UV lamps were turned off. During the next three weeks, medium-pressure UV lamps were kept on 24 h per day. The third week, we reduced the level of the injected chlorine into water, and the last week we also reduced the water renewal volume by 27%. Our results showed that bacteriological parameters remained within allowable french limits. When medium-pressure UV lamps were kept on, total, free and active chlorine levels were significantly increased (P<0.001), whereas combined chlorine level were significantly decreased (P<0.001 and P<0.05, respectively). The levels of chloroform and bromodichloromethane were significantly increased when medium-pressure UV lamps were kept on (P<0.001), whereas chlorodibromomethane and bromoform levels significantly decreased (P<0.05 and P<0.001, respectively). The additional formation of chloroform and bromodichloromethane may be explained by the increase in active chlorine and by radicalizing mechanisms initiated by UV radiation.
authors.affiliation: UPRES 2991, Efficience et Déficience Motrices, Faculté des Sciences du Sport, Université Montpellier 1, 34090 Montpellier, France. delphine.cassan@univ-montp1.fr
authors.forename: Delphine
authors.initials: D
authors.lastname: Cassan
authors.forename: Béatrice
authors.initials: B
authors.lastname: Mercier
authors.forename: Françoise
authors.initials: F
authors.lastname: Castex
authors.forename: André
authors.initials: A
authors.lastname: Rambaud
mesh_terms: D006843:Hydrocarbons, Chlorinated / Q000032:analysis* / Q000528:radiation effects; D013551:Swimming Pools / Q000592:standards*; D014466:Ultraviolet Rays; D014867:Water / Q000032:analysis / Q000592:standards*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000528:radiation effects; D018508:Water Purification / Q000295:instrumentation / Q000592:standards*
chemical_list: D006843:Hydrocarbons, Chlorinated; D014874:Water Pollutants, Chemical; D014867:Water