Respiratory symptoms and bronchial responsiveness in lifeguards exposed to nitrogen trichloride in indoor swimming pools.

Abstract

Objectives-To measure the levels of exposure to nitrogen trichloride (NCl 3 ) in the atmosphere of indoor swimming pools and to examine how they relate to irritant and chronic respiratory symptoms, indices of pulmonary function, and bronchial hyperresponsiveness to methacholine in lifeguards working in the pools. Method-334 lifeguards (256 men; 78 women) recruited from 46 public swimming pools (n=228) and 17 leisure centre swimming pools (n=106) were examined. Concentrations of NCl 3 were measured with area samplers. Symptoms were assessed by questionnaire and methacholine bronchial challenge (MBC) test by an abbreviated method. Subjects were labelled MBC+ if forced expiratory volume in one second (FEV 1 ) fell by >20%. The linear dose-response slope was calculated as the percentage fall in FEV 1 at the last dose divided by the total dose given. Results-1262 samples were taken in the 63 pools. Mean NCl 3 concentrations were greater in leisure than in public pools. A significant concentration-response relation was found between irritant eye, nasal, and throat symptoms-but not chronic respiratory symptoms-and exposure concentrations. Among women, the prevalence of MBC+ was twice as great as in men. Overall, no relation was found between bronchial hyperresponsiveness and exposure. Conclusions-The data show that lifeguards exposed to NCl 3 in indoor swimming pools are at risk of developing irritant eye, nasal, and throat symptoms. Exposure to NCl 3 does not seem to carry the risk of developing permanent bronchial hyperresponsiveness, but this association might have been influenced by self selection. The possibility that subjects exposed to NCl 3 are at risk of developing transient bronchial hyperresponsiveness cannot be confidently ruled out. (Occup Environ Med 1998;55:258-263) Keywords: indoor swimming pools; lifeguards; irritation; respiratory symptoms; nitrogen trichloride World wide, many millions of people take pleasure in swimming regularly in swimming pools. Traditionally, pool attenders face the risk of developing dermatological diseases due to exposure to micro-organisms-for example, Mycobacterium balnei, Mollusculum contagiosumfound in the pool water or in the surrounding area.1 Also, those attending indoor pools are at risk of inhaling aerosols of microorganisms-for example, Legionella pneumophila-or chemical substances released by the reaction between disinfecting agents added to the pool water and organic matter of human origin. 1In 1993, the departments of several health insurance agencies in France that deal with occupational diseases reported unusually high rates of ocular and respiratory irritation among lifeguards employed at various indoor pools that used chlorine as a disinfecting agent. After this observation, exposure was monitored by chemists from our institution, and showed that among the possible irritants present in the air of the pools only the chloramines were detected in non-negligible quantities. Moreover, nitrogen trichloride (NCl 3 ) was the main chloramine present.2 This e...

Exposure to trichloramine and respiratory symptoms in indoor swimming pool workers

“…Measured chloramine levels in the present study exceeded this comfort level regularly. MASSIN et al [3] found average concentrations of 0.67 mg?m -3 chloramine in leisure pools, which are of the same magnitude as present findings, and 0.24 mg?m -3 chloramine in public pools. HERY et al [4] found approximately similar values (0.64 and 0.27 mg?m -3 , respectively).…”

“…MASSIN et al [3] studied the relationship between trichloramine air levels and irritant and chronic respiratory symptoms, indices of lung function and bronchial hyperresponsiveness (BHR) in 334 French lifeguards. No associations were found between exposure and BHR, chronic bronchitis and asthma.…”

“…It is considered to be irritating to the eye and upper airway [1]. Conditions that determine production and air levels of trichloramines are believed to depend on the degree of water chlorination, contamination of water by nitrogen-containing compounds (which depends on the number of bathers, as well as their behaviour and hygiene), water temperature, water circulation and ventilation [3,4]. However, the chemical composition of swimming pool air is extremely complex and how these factors are associated with trichloramine levels in air is poorly understood [1].…”

Effect of pH on the formation of disinfection byproducts in swimming pool water – Is less THM better?

“…NCl 3 is suspected to be responsible for the appearance of asthma to swimmers, swimming teachers and lifeguards (Thickett et al, 2002) and to cause eye, nasal and throat irritations (Massin et al, 1998;Thickett et al, 2002). NCl 3 is a compound with low solubility in water; it is four times more volatile than chloroform and has a penetrating odor, which makes it one of the most important air pollutants of indoor pools (Schmalz et al, 2011).…”

Chapter 2 Chemical hazards

“…The chloramines and bromamines, particularly nitrogen trichloride and nitrogen tribromide, which are both volatile (Holzwarth et al, 1984), can give rise to signifi cant eye and respiratory irritation in swimmers and pool attendants (Massin et al, 1998). In addition, nitrogen trichloride has an intense and unpleasant odour at concentrations in water as low as 0.02 mg/l (Kirk & Othmer, 1993).…”