Asthma and Whirlpool Baths
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《新英格兰医药杂志》
To the Editor: Public baths and swimming pools need to be disinfected, and this is usually accomplished by chlorination of the water. Exposure to chlorinated pools, however, may affect the lung epithelium and, along with other factors, may be associated with the increased prevalence of childhood asthma.1 In addition, the chloramines,2,3 which are generated from the reaction of hypochlorite with ammonia and amino compounds that originate from sweat and urine, are substances that are highly volatile and irritating to the airways. The magnitude of exposure to these substances depends on the number of bathers, the water temperature, and local air recirculation. Many recreation facilities offer the use of heated and chlorinated whirlpool baths (such as Jacuzzi baths and hot tubs), in which the rate of vaporization is increased proportionally to the temperature of the water and the action of the water jets.
We examined the effect of whirlpool baths on airway reactivity in patients with mild asthma. Eight patients (seven men and one woman, 20 to 42 years of age) with stable, mild, persistent asthma were enrolled, after informed consent was obtained. This study was approved by the institutional review board. Maintenance treatment including long-acting beta-agonists, inhaled corticosteroids, or both was suspended for either three or six days before the study. The use of short-acting bronchodilators was allowed. All patients had positive results on methacholine-provocation testing and had a baseline reading of forced expiratory volume in one second (FEV1) of 80 percent of the predicted value or higher. A day before the study, the patients underwent a methacholine-provocation test; the same batch of methacholine was used the next study day. After baseline spirometric testing, the patients were immersed in an active whirlpool bath for 12 minutes. Chlorine was used as a disinfectant. The level of chlorine was continuously monitored, and evaporated chlorine was replaced. The bath was followed (two to three minutes after the patients exited the tub) by repeated spirometric testing and another methacholine-provocation test.
No patients reported symptoms during or after the whirlpool bath. After the whirlpool bath, a 20 percent reduction in FEV1 was documented in six patients after two earlier dilutions of methacholine, as compared with baseline; in one patient after one previous dilution, as compared with baseline; and in one patient immediately after exposure to the bath mist (Table 1). (With each dilution, there was more methacholine and less water.) Our findings suggest that hot chlorinated pools and whirlpool baths may have a detrimental effect on patients with asthma.
Table 1. Results of Methacholine Provocation Testing before and after a Whirlpool Bath.
David Stav, M.D.
Assaf Harofeh Medical Center
70300 Zeriffin, Israel
dstav@post.tau.ac.il
Michal Stav, B.Sc.
Bar Ilan University
52900 Ramat Gan, Israel
References
Bernard A, Carbonnelle S, Michel O, et al. Lung hyperpermeability and asthma prevalence in schoolchildren: unexpected associations with the attendance at indoor chlorinated swimming pools. Occup Environ Med 2003;60:385-394.
Massin N, Bohadana AB, Wild P, Hery M, Toamain JP, Hubert G. Respiratory symptoms and bronchial responsiveness in lifeguards exposed to nitrogen trichloride in indoor swimming pools. Occup Environ Med 1998;55:258-263.
Thickett KM, McCoach JS, Gerber JM, Sadhra S, Burge PS. Occupational asthma caused by chloramines in indoor swimming-pool air. Eur Respir J 2002;19:827-832.
We examined the effect of whirlpool baths on airway reactivity in patients with mild asthma. Eight patients (seven men and one woman, 20 to 42 years of age) with stable, mild, persistent asthma were enrolled, after informed consent was obtained. This study was approved by the institutional review board. Maintenance treatment including long-acting beta-agonists, inhaled corticosteroids, or both was suspended for either three or six days before the study. The use of short-acting bronchodilators was allowed. All patients had positive results on methacholine-provocation testing and had a baseline reading of forced expiratory volume in one second (FEV1) of 80 percent of the predicted value or higher. A day before the study, the patients underwent a methacholine-provocation test; the same batch of methacholine was used the next study day. After baseline spirometric testing, the patients were immersed in an active whirlpool bath for 12 minutes. Chlorine was used as a disinfectant. The level of chlorine was continuously monitored, and evaporated chlorine was replaced. The bath was followed (two to three minutes after the patients exited the tub) by repeated spirometric testing and another methacholine-provocation test.
No patients reported symptoms during or after the whirlpool bath. After the whirlpool bath, a 20 percent reduction in FEV1 was documented in six patients after two earlier dilutions of methacholine, as compared with baseline; in one patient after one previous dilution, as compared with baseline; and in one patient immediately after exposure to the bath mist (Table 1). (With each dilution, there was more methacholine and less water.) Our findings suggest that hot chlorinated pools and whirlpool baths may have a detrimental effect on patients with asthma.
Table 1. Results of Methacholine Provocation Testing before and after a Whirlpool Bath.
David Stav, M.D.
Assaf Harofeh Medical Center
70300 Zeriffin, Israel
dstav@post.tau.ac.il
Michal Stav, B.Sc.
Bar Ilan University
52900 Ramat Gan, Israel
References
Bernard A, Carbonnelle S, Michel O, et al. Lung hyperpermeability and asthma prevalence in schoolchildren: unexpected associations with the attendance at indoor chlorinated swimming pools. Occup Environ Med 2003;60:385-394.
Massin N, Bohadana AB, Wild P, Hery M, Toamain JP, Hubert G. Respiratory symptoms and bronchial responsiveness in lifeguards exposed to nitrogen trichloride in indoor swimming pools. Occup Environ Med 1998;55:258-263.
Thickett KM, McCoach JS, Gerber JM, Sadhra S, Burge PS. Occupational asthma caused by chloramines in indoor swimming-pool air. Eur Respir J 2002;19:827-832.