Abstract
The amount of ammonia in the air contaminated by the discontinuance of water washing of the laboratory animal room and that of ammonia absorbed in the water placed in the same room were measured by using Nessler reagent. From the air, 0.0478-0.1060 mg/liter of ammonia i. e., beyond the tolerable amount of ammonia in a special room, was detected, and the water in a drinking bottle for mice absorbed about 1.7 mg/liter of ammonia during 24 hours. On the other hand, five goldfish kept in the same room began to die when the ammonia level reached 29.1 mg and were exterminated when 46.4 mg of ammonia were absorbed by a liter of water. Futhermore, similar results were obtained when other five healthy goldfish were exposed to these amounts of ammonia. From these results, it was recognized that ammonia was one of the important factors for contamination of the air in that room and that air washing was indispensable.
