Chloroform present in the swimming water disinfected with sodium hypochlorite is released to the air of swimming pools. The air chloroform concentrations were measured in two swimming pools A and B which applied both sodium hypochlorite and ozone. Their mean concentrations are 28.0 ㎎/㎥ and 33.6 ㎍/㎥ in the swimming pools A and B, respectively. On the other hand, the mean water chloroform concentrations in the swimming pools A and B were 23.9 ㎍/ℓ and 19.5 ㎍/ℓ, respectively. The air chloroform concentrations were lower in the swimming pools A and B than those reported by previous studies abroad employed the swimming pools which applied sodium hypochlorte only for water disinfection. The water chloroform concentrations were also lower in this study than in the previous studies. The relationship between the air and water chloroform concentrations measured in this study was significant with p=0.002 and R^2=O.42. At similar time to the indoor air sampling, outdoor air samples were collected at two sites near each of the swimming pools A and B. The mean outdoor air chloroform concentrations near the swimming pools A and B were 0.41 ㎍/㎥ and 0.16 ㎍/㎥, respectively. The outdoor air chloroform concentrations measured in this study were equal to or lower than those reported by previous studies abroad. The chloroform dose inhaled for a typical one-hour swim was estimated to be 25.9 ㎍ per person, corresponding to a specific 0.37 ㎍/㎏ body weight. for a reference 70 ㎏ male adult, while the inh lation dose of chloroform from the outdoor air was estimated to be 5.6 ㎍ per person per day, corresponding to a specific 0.08 ㎍/㎏/day for the same reference male adult.

Chlorinated water in swimming pools contains chloroform at elevated levels compared to chlorinated drinking water. Chloroform levels in four indoor swimming pools(swimming pools A, B and C in a city of Korea and swimming pool D in a city of New Jersey in the United States) were examined. The chloroform levels in the water of swimming pool C (city-managed) were shown to be significantly(p=0.0001) different from those of private swimming pools A and B: the mean chloroform levels in the pools A, B, and C are 22.8, 17.8, and 31.1 ㎍/ℓ respectively. Furthermore, all of these chloroform levels are significantly(p=0.0001) different from those of New Jersey: chloroform concentration of the Korean pools ranged from 10.9 ㎍/ℓ to 47.9 ㎍/ℓ with a mean of 23.2 ㎍/ℓ, while it ranged from 27 ㎍/ℓ to 96 ㎍/ℓ with a mean of 64.4 ㎍/ℓ in the New Jersey pool. The disinfection processes would cause part of this difference since the swimming pools in Korea applied both chlorination and ozonation method, while the swimming pool in New Jersey used chlorination method only. It was implied that swimming parameters inconsistently vary, resulting in fluctuation of and no constant accumulation of chloroform in the water with the change of time for the day. A regression analysis showed no relationships between sampling time and chloroform concentrations for the sampling day in the swimming pools of Korea. A F-test indicated no significant difference of chloroform concentrations in the morning and afternoon samples collected in the swimming pools. Ingestion dose was estimated to be 0.58 ㎍ from an hour swimming in a city of Korea, taking into accounting an average of 23.2 ㎍/ℓ in swimming pools in the city. In extreme situation, the ingestion dose was estimated to he 12.0 ㎍ from an hour swimming in a city of Korea.