(Reuters Health) - Lifeguards who spend more than 500 hours a year working at indoor pools are two to six times more likely than colleagues who are exposed less often to have coughs, asthma, and throat and eye irritation, according to a small study in Canada.
Most of the symptoms improved after the lifeguards left work, suggesting that chemicals used to maintain indoor pools may be triggering the symptoms, the study authors report in the International Journal of Environmental Health Research.
“In the past years, in the province of Quebec as well as in other jurisdictions, lifeguards’ and competitive swimmers’ awareness of potential irritative effects related to indoor swimming pools increased,” lead author Gabrielle Bureau told Reuters Health in an email.
“However, this study clearly highlights the fact that indoor swimming pool environments may have adverse health effects on the respiratory system and suggest a relationship between respiratory symptoms and the time spent in this environment as a lifeguard,” said Bureau, a researcher at the Department of Social and Preventive Medicine of Laval University in Quebec City.
The researchers surveyed current and former licensed lifeguards using online questionnaires to assess their exposure to swimming pool environments and certain symptoms such as cough, sputum, shortness of breath, wheezing, lung congestion, sneezing, throat or eye irritation, hoarseness, stuffy nose and ear pain.
In addition, the lifeguards were asked if they had been diagnosed with asthma or used asthma medications.
Of the 870 respondents, 601 were currently working as lifeguards and three quarters were women. Their ages ranged from 18 to 64 years, with an average age of 22 for current lifeguards and 29 for former lifeguards.
About 78 percent of the lifeguards reported having at least one respiratory symptom in the previous year and 23 percent reported having physician-diagnosed asthma.
Lifeguards exposed to the pool more than 500 hours during the previous year were about two and a half times more likely to have a cough or sore throat than those exposed less than 50 hours. They were also over four times more likely to have eye irritation.
Among lifeguards with asthma, those exposed more than 500 hours a year were six times more likely to have asthma attacks than those with little or no exposure to the indoor pool environment.
“We found that the most exposed lifeguards in the past 12 months were more susceptible to have a cough, hoarseness and throat and eye irritation during this period. Furthermore, we found that most exposed lifeguards over their lifetime had significantly more chances of suffering from various symptoms while on duty,” Bureau said.
“Most of the swimming pools worldwide are disinfected with chlorine-based disinfectants,” she noted.
The reaction between free chlorine and organic matter such as sloughed skin cells, cosmetics, urine, sunscreen and sweat in water generates a high number of contaminants called disinfection-by-products (DBP), Bureau said.
“One of those DBPs is the trichloramine (NCl3), a highly volatile contaminant that gives indoor swimming pools their characteristic ‘chlorine smell,’” she said, and NCl3 is the most likely contaminant to cause irritative symptoms.
“The present findings underscore the need to implement and respect preventive measures. To that extent, it is important to limit the entry of organic matter into the water to decrease the amount of disinfection-by-products generated,” she said.
Taking specific hygiene measures such as using the toilet and showering with soap before swimming, using swimming caps, taking children to the toilet frequently, using diapers specially designed for swimming would be important, Bureau said.
“Moreover, measures like adequate filtration, tight chlorination control, regular monitoring of chlorination parameters, adequate ventilation at all times are essential to improve water and air quality in indoor swimming pools and prevent the occurrence of irritative and respiratory symptoms,” she said.
SOURCE: bit.ly/2t8mF0o International Journal of Environmental Health Research, online June 25, 2017.