Indoor Swimming Pool

Swimming is a popular sport for children and adults alike. Swimming is often recommended as the best sport for children with asthma. This is mainly because moist air inhalation is less likely to trigger exercise-induced asthma. For obvious reasons, both public and private pools need to be disinfected. Chlorination is the most common method of water disinfection. The use of chlorinated products to disinfect water can have a variety of undesirable effects. This is true for any human or technological intervention. The chlorination of public water supplies can affect respiratory health, especially for swimming instructors or attendants and those who visit the pools, including children, the general population, and competitive swimmers. The respiratory effects of chlorinated water are not well understood. Although chlorination has been a hot topic in recent years, the health risks of swimming pools have received less attention. The air in chlorinated pools is not included in the reports, nor are the more recent ones. This is even though the air quality of these pools can be irritant, even when well maintained.

Water chlorination

The most common method of disinfecting public water supplies and pools is chlorination. Chlorine can be added as a gas (Cl 2) that quickly hydrolyzes into hypochlorous (HOCl), as well as sodium or calcium (OCl 2) hypochlorite. Hypochlorite, for disinfection, may also be produced by adding so-called hypochlorite-generating agents, such as dichloro isocyanurate, to water. Both HOCl (OHCl – ), and the hypochlorite isomer (OCl – ), are present in water with a pH of 6.5 to 8.5.

Chlorinated swimming pools can cause serious health hazards

Acute exposure to high levels of chlorine gas resulting from explosions, leaks, or malfunctioning of chlorine-disinfection installations, is a well-known problem. Health consequences can be severe or mild. The severity of symptoms depends on the intensity ( i.e., a combination of aerial concentrations with duration of exposure). These include laryngeal swelling, asthma attacks, chemical burns to the upper and lower mucosa, and even chemical pneumonitis. Hyperventilation, transient lachrymation, and nasopharyngeal inflammation are the less severe manifestations. In the case of school parties, these victims may arrive as a group and with more emotion than seriousness. Inhalation injuries should be treated as severe, and structural or functional complications, such as reactive airway dysfunction syndrome (RADS), must be considered. Even for medicolegal purposes, it is prudent not to discharge inhalation injury victims without a thorough assessment of their pulmonary function. This includes measurements of bronchial response and diffusion capacity or blood-gas analyses with standard exercise. Inhaling corticosteroids or systemic corticosteroids to victims of inhalation injury has not been evaluated in controlled studies. However, it is justified based on anecdotal and theoretical evidence. After 6-8 weeks, it is important to recommend a follow-up for respiratory symptoms, spirometry, and, if needed, nonspecific bronchial reaction.

Exposure to swimming pool air

The “normal” indoor air of swimming pools can affect the upper respiratory tract and eyes similarly to specific industrial environments. It is common knowledge that the smell of swimming pool atmospheres can be attributed to the “chlorine.” However, recent studies have shown, at least for the medical community, that the smell of swimming pool air and its irritating properties are primarily due to chloramines. Monochloramine, dichloramine, and trichloramine are all chloramines. They are produced by the hypochlorite reaction with ammonia from swimmers’ sweat and urine. Trichloramine is particularly volatile and can easily partition from water to the air. The factors that affect the production of chloramines and the air level of these compounds include the amount of chlorine in the water, the nitrogen contamination (which is dependent on bathers’ behavior and hygiene), the temperature of the water, and the air circulation. These agents are a severe threat to people who work in these environments.

For example, swimming instructors or pool supervisors. They may experience respiratory symptoms. More information about the health effects of these irritants on employees needs to be provided. I have made proposals, but no health-based chloramine occupational limits seem to exist. Thickett and colleagues describe three cases of occupational asthma among swimming-pool workers in this issue. There is no doubt, based on the descriptions of the patients and the fact that two of them had positive bronchial reactivity tests to chloramine, that these people had occupational asthma. The mechanism behind the asthma is still unknown. However, the claim that it is due to immunological sensibilization can only be supported by the fact that the subjects reacted uniquely to reported low chloramine levels. Therefore, the possibility of a pure irritant was ruled out, as the subjects did not have an increased bronchial response to histamine. Irritant-induced asthma caused by “low-level exposure” to irritants is controversial and has only limited epidemiological or experimental support.

The article by Thickett et al. is essential from a clinical perspective, as it provides evidence that asthma caused by swimming pools can be an occupational disease. This is uncommon.S. Burge, the senior author of this article (Dept of Respiratory Medicine Occupational Lung Diseases Unit Heartlands Hospital Birmingham, UK), presented one of three cases during an interactive occupational grand round at the 1998 European Respiratory Society annual meeting in Geneva. When asked, “Have You Seen Cases of Swimming Pool Asthma?”, 24% of the audience responded yes, and 19% said maybe.

The report by Thickett and others may also have implications for jobs outside of swimming pools. The cleaning process also exposes workers to various irritants, including bleach. In this way, cleaning staff, both casual and professional, are at risk for acute inhalation injuries as a result of mixing incompatibilities. Recent epidemiological studies also indicate that cleaners fall into a higher-risk category of workers. The causes of asthma among cleaners are still unknown, even though specific reactions to cleaning products have been reported. The role of chloramines should also be further investigated.

Swimming and its health

The effect of the swimming pool atmosphere on bathers is also a subject of interest. Swimming is beneficial for asthmatic children because breathing moist air reduces exercise-induced bronchoconstriction. The possible exposure to irritants from chlorinated water has not been addressed in publications with asthmatics undergoing swimming-training programs. Anecdotal evidence suggests that asthmatic people do not tolerate chlorinated swimming pools very well. However, this is not a significant problem. It has also been shown that competitive swimmers are more likely to suffer from bronchial hyperresponsiveness and asthma than other athletes. These observations have no known cause, although irritants may be a factor.