Hygienic Inspection of the Whirlpool Baths by Using ATP Bioluminescence Method

For the Legionella control, the ATP bioluminescence method used as a biological screening test of the whirlpool baths in Nagasaki prefecture was investigated. The provisional threshold value, which was fixed from mean+2SD of the ATP bioluminescence value = Relative Light Unit (RLU) among samples under the minimum RLU sample with bacterial contaminant, could clearly divide low-contaminant water into the high-risk baths, which was contaminated with Legionella spp. and/or naked amoeba, at 4.07 logRLU/ml (P<0.01). This value was therefore showed to be the utility as the administrative standard of the whirlpool baths with simultaneously testing of free available chlorine concentration.