Article

Outbreaks of Short-Incubation Ocular and Respiratory Illness Following Exposure to Indoor Swimming Pools

Enteric Diseases Epidemiology Branch, National Center for Zoonotic, Vector-borne and Enteric Disease, Centers for Disease Control and Prevention, Atlanta, GA 30333 USA.
Environmental Health Perspectives (Impact Factor: 7.98). 03/2007; 115(2):267-71. DOI: 10.1289/ehp.9555
Source: PubMed

ABSTRACT

Chlorination destroys pathogens in swimming pool water, but by-products of chlorination can cause human illness. We investigated outbreaks of ocular and respiratory symptoms associated with chlorinated indoor swimming pools at two hotels.
We interviewed registered guests and companions who stayed at hotels X and Y within 2 days of outbreak onset. We performed bivariate and stratified analyses, calculated relative risks (RR), and conducted environmental investigations of indoor pool areas.
Of 77 guests at hotel X, 47 (61%) completed questionnaires. Among persons exposed to the indoor pool area, 22 (71%) of 31 developed ocular symptoms [RR = 24; 95% confidence interval (CI), 1.5-370], and 14 (45%) developed respiratory symptoms (RR = 6.8; 95% CI, 1.0-47) with a median duration of 10 hr (0.25-24 hr). We interviewed 30 (39%) of 77 registered persons and 59 unregistered companions at hotel Y. Among persons exposed to the indoor pool area, 41 (59%) of 69 developed ocular symptoms (RR = 24; 95% CI, 1.5-370), and 28 (41%) developed respiratory symptoms (RR = 17; 95% CI, 1.1-260) with a median duration of 2.5 hr (2 min-14 days). Four persons sought medical care. During the outbreak, the hotel X's ventilation system malfunctioned. Appropriate water and air samples were not available for laboratory analysis. CONCLUSIONS AND RELEVANCE TO PROFESSIONAL PRACTICE: Indoor pool areas were associated with illness in these outbreaks. A large proportion of bathers were affected; symptoms were consistent with chloramine exposure and were sometimes severe. Improved staff training, pool maintenance, and pool area ventilation could prevent future outbreaks.

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    • "An increase in asthma due to exposure from CHL in indoor swimming pool areas has been reported (Bernard et al., 2003), which may be due to an irritant effect of CHL or other non-specific mechanisms. Bowen et al. (2007) have suggested that contact with CHL or inhalation of CHL-contaminated air is associated with respiratory illness—as is expected with a mucosal irritant—and that dermal absorption or ingestion may not be necessary to produce symptoms. Therefore, further studies to examine the effects of inhalational exposure to CHL on the immune cell populations within the lungs of mice and to determine if there exists an exacerbation of asthma symptoms following challenge of these mice with respiratory antigens are warranted. "
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    • "Gagnaire et al. (1994) demonstrated NCl 3 to be a respiratory irritant to mice, and more recent studies have indicated NCl 3 to contribute to acute ocular and respiratory irritation symptoms in lifeguards and swimming pool workers (Jacobs et al., 2007; Dang et al., 2010). Retrospective studies have shown positive correlation between irritation symptoms among swimmers and patrons and high gas-phase NCl 3 concentration at indoor pool facilities (Kaydos-Daniels et al., 2008; Bowen et al., 2007). NCl 3 is a volatile compound that may be transferred from the liquid phase to gas phase in a chlorinated swimming pool. "
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    • "Gagnaire et al. (1994) demonstrated NCl 3 to be a respiratory irritant to mice, and more recent studies have indicated NCl 3 to contribute to acute ocular and respiratory irritation symptoms in lifeguards, swimming pool workers, and competitive swimmers (Jacobs et al., 2007; Dang et al., 2010; Clearie et al., 2010). Previous retrospective studies have shown positive correlations between irritation symptoms among swimmers and patrons and high gas-phase NCl 3 concentration at indoor pool facilities (Kaydos-Daniels et al., 2008; Bowen et al., 2007). Among the DBPs that are formed in pools, eleven volatile compounds have been identified that could adversely affect air quality in chlorinated, indoor pool facilities: "
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