Association between exposure to airborne trichloramine and health effects in indoor swimming pool workers.

OBJECTIVE: The main objective of this study was to comprehensively investigate the association between trichloramine (TCA) exposure and respiratory health effects in swimming pool workers. METHODOLOGY: In this study, air sampling was performed for TCA concentrations at fixed locations (static measurements) and on individual workers (personal measurements) in six indoor public swimming pools during periods of high swimmer attendance over the winter school break. Health effects were evaluated using questionnaires and fractional exhaled nitric oxide (FENO) tests performed before and after the working day. RESULTS: In these swimming pools, the environmental TCA concentration ranged from 0.11 to 0.88 mg/m³. Worker exposure ranged from 0.05 to 0.72 mg/m³ for personal measurements. Furthermore, in each swimming pool, the average worker exposure to TCA exceeded the recommended occupational exposure limit of 0.35 mg/m³. Personal TCA measurements were consistently lower than static measurements performed around the pool, with a reduction ranging from 21% to 49%. This can be explained by the time that the workers spend in the pool area, office, and break room. The most common respiratory health effects self-reported by the workers were coughing, shortness of breath, and sneezing with prevalence rates of 38%, 37%, and 35%, respectively. This study demonstrated an association between TCA exposure and eye irritation. Analysis of the FENO tests revealed that individuals with preexisting asthma or allergies exhibited sustained FENO elevation. CONCLUSION: The findings suggest that occupational exposure to TCA in indoor swimming pools is a matter of concern. Implementing and improving workplace safety measures is crucial for safeguarding the respiratory health of swimming pool workers.

Effect of exposure to disinfection by-products during swimming exercise on asthma-related immune responses.

Swimming is a widely practiced exercise in modern society, where there is a heightened interest in health. The exceptional benefits of swimming are well-known, yet the issue of water quality management inevitably arises due to its nature as an aquatic exercise. Several studies reported that chlorine disinfectants commonly used in swimming pool water disinfection could degrade into toxic disinfection by-products (DBPs) and suggested that the DBPs might induce respiratory disorders, including asthma. Conversely, there were also reports that the DBPs had no significant effects on respiratory conditions. In this study, we investigated the influence of swimming exercise and DBPs on asthma. The decomposition products had little effect on the number of T cells in various immune organs. However, swimming exercise was found to increase the cell count in proportion to the exercise duration. Nevertheless, there were no significant changes in other immune cells and the secretion of asthma-related cytokines. These findings indicate that the effects of swimming pool DBPs on respiratory conditions during swimming exercise are either negligible or absent, and instead, the immunological benefits gained through consistent swimming exercise outweigh any potential drawbacks.

Modelling chloroform in indoor swimming pool air and water: the influences of internal air circulation and occupants.

The release of chloroform from water to air in an indoor swimming pool (ISP) exhibits complex physicochemical interactions among many variables, including environmental conditions, occupant activities, and geometry of the ISP. By combining the relevant variables, a structured mathematical model, the double-layer air compartment (DLAC) model, was developed to predict the level of chloroform in ISP air. A physical parameter, the indoor airflow recycle ratio (R), was incorporated into the DLAC model due to internal airflow circulation resulting in the ISP structural configuration. The theoretical R-value for a specific indoor airflow rate (vy) can be found by fitting the predicted residence time distribution (RTD) to the simulated RTD from computational fluid dynamics (CFD), showing a positive linear relationship with vy. The mechanical energies induced by occupant activities were converted into a lumped overall mass-transfer coefficient to account for the enhanced mass transfer of chloroform from the water into the air and mixing in ISP air. The DLAC model predicted that chloroform air concentrations were statistically less accurate without considering the influence of R compared with the online open-path Fourier transform infrared measurements. A novel index, the magnitude of emission (MOE) from swimmers, was linked to the level of chloroform in ISP water. The capability of the DLAC model associated with the MOE concept may facilitate upgrading the hygiene management of ISPs, including the ability to administer necessary chlorine additives in pool water and monitor the chloroform in ISP air.

Comparison of sampling collection strategies for assessing airborne trichloramine levels in indoor swimming pools.

Since 1995, Hery's trichloramine sampling procedure has been widely used to determine trichloramine exposure in indoor swimming pools. This method consists of pumping air at a 1 L/min flow rate for 2 h through a Teflon prefilter and two quartz fiber filters. Modified Hery methods have been reported using different sampling pump flow rates and types of prefilters. It is possible that the prefilter type or sample collection pump flow rate influenced the results of these studies. This study is designed to evaluate the effects of different cassette assemblies and sampling flow rates on the levels of measured trichloramine. Laboratory tests were performed using a trichloramine production setup designed for this study. Workplace measurements were carried out at four indoor swimming pools. Different prefiltering strategies were used: no prefilter, glass prefilter or Teflon prefilter in the sampling cassette, and an original separable prefilter cassette is presented in this study. Laboratory tests indicated that at trichloramine concentrations higher than 1 mg/m3, the percentage of trichloramine captured on the first filter could be less than 75%, which demonstrated possible loss of the material during sampling. An investigation of the prefilter effect on the sampling strategy using different cassette assemblies revealed that using a separable cassette assembly prevented overestimations of trichloramine levels. Furthermore, there were no significant differences between trichloramine concentrations measured at flow rates (from 0.5 to 2 L/min) in swimming pools.

Within-day variation and health risk assessment of trihalomethanes (THMs) in a chlorinated indoor swimming pool in China.

Trihalomethanes (THMs) are the most common species of disinfection by-products (DBPs) in swimming pools and have received widespread attention due to their risk to public health. However, studies examining within-day variation and the carcinogenic health risks from exposure to THMs in indoor swimming pools are limited. Our study aimed to detect the within-day variation of four THMs categories and carcinogenic health risk in indoor swimming pool water in Taiyuan, China, and to examine the correlations between THMs and environmental parameters. Our results showed chloroform (TCM) was the most abundant component in THMs with median concentrations from 0.038-0.118 µg/m3. TCM and THMs were significantly positively correlated with FCl and significantly negatively correlated with the cumulative number of swimmers (CNS) in the swimming pool. The concentration of total THMs and TCM, lifetime average daily doses (LADD) of TCM, and the total lifetime cancer risks (ELCR) values of THMs declined with time with the highest level occurring at 8:00 am. ELCR values of THMs were in the range of 1.368 × 10-5-1.968 × 10-5, which exceeded the negligible risk level (10-6) defined by US EPA. Our results suggest that THM occurrence and the carcinogenic health risks in pool water varied temporally. Exposure to pool water THMs may pose a carcinogenic risk to human health, especially at the pool's opening time.

+Chlorination by-products in indoor swimming pools: Development of a pilot pool unit and impact of operating parameters.

Chlorine addition in swimming pools ensures the microbiological quality of the water and the bathers' safety. However, water chlorination is associated with disinfection byproducts (DBP) formation and adverse health effects. The impact of operating parameters and innovative water treatment systems on DBPs levels has been reported in several studies, but sampling campaign in real pools remain difficult to carry out, mainly due to unexpected attendance variations. This study presents the development of a pilot pool plant allowing to perform experiments under controlled and reproducible conditions. Bathers inputs were simulated both for the organic load and for the mechanical agitation of water. Two sampling campaigns were performed during the building of the pilot, before and after the hall was closed. Key operating parameters such as chlorine dose, water temperature and attendance were controlled and monitored. DBP levels in the pilot plant were representative of French indoor swimming pools and the impact of bathers' activity was visible on volatile DBPs. Furthermore, correlations could be stated between operating parameters and DBP levels. Stripping effectively reduced volatile DBP concentrations in water. Moreover, energy consumption data, which are usually very scarce in experimental studies, showed the influence of heat pump consumption on the global energy consumption.

Comprehensive assessment of the indoor air quality in a chlorinated Olympic-size swimming pool.

Elite swimmers and swimming pool employees are likely to be at greater health risk due to their regular and intense exposure to air stressors in the indoor swimming pool environment. Since data on the real long-term exposure is limited, a long-term monitoring and sampling plan (22 non-consecutive days, from March to July 2017) was carried out in an indoor Olympic-size pool with a chlorine-based disinfection method to characterize indoor environments to which people involved in elite swimming and maintenance staff may be exposed to. A comprehensive set of parameters related with comfort and environmental conditions (temperature, relative humidity (RH), carbon dioxide (CO2) and monoxide and ultrafine particles (UFP)) were monitored both indoors and outdoors in order to determine indoor-to-outdoor (I/O) ratios. Additionally, an analysis of volatile organic compounds (VOC) concentration and its dynamics was implemented in three 1-hr periods: early morning, evening elite swimmers training session and late evening. Samplings were simultaneously carried out in the air layer above the water surface and in the air surrounding the pool, selected to be representative of swimmers and coaches/employees' breathing zones, respectively. The results of this work showed that the indoor climate was very stable in terms of air temperature, RH and CO2. In terms of the other measured parameters, mean indoor UFP number concentrations (5158 pt/cm3) were about 50% of those measured outdoors whereas chloroform was the predominant substance detected in all samples collected indoors (13.0-369.3 µg/m3), among a varied list of chemical compounds. An I/O non-trihalomethanes (THM) VOC concentration ratio of 2.7 was also found, suggesting that, beyond THM, other potentially hazardous VOC have also their source(s) indoors. THM and non-THM VOC concentration were found to increase consistently during the evening training session and exhibited a significant seasonal pattern. Compared to their coaches, elite swimmers seemed to be exposed via inhalation to significantly higher total THM levels, but to similar concentrations of non-THM VOC, during routine training activities. Regarding swimming employees, the exposure to THM and other VOC appeared to be significantly minimized during the early morning period. The air/water temperature ratio and RH were identified as important parameters that are likely to trigger the transfer processes of volatile substances from water to air and of their accumulation in the indoor environment of the swimming pool, respectively.

Predicting health risk from exposure to trihalomethanes in an Olympic-size indoor swimming pool among elite swimmers and coaches.

Disinfection by-products (DBP) such as trihalomethanes (THM) are formed when chlorine and bromine interact with natural organic materials in chlorine-treated swimming pools. Epidemiological evidence demonstrated an association between exposure to swimming pool environment and adverse health effects. Therefore, this study aimed to assess carcinogenic and non-carcinogenic risk of long-term exposure of elite swimmers and their coaches. In an Olympic-size indoor chlorinated swimming pool, THM levels were determined in water (21-69 µg/L), in the boundary layer above the water surface (59-397 µg/m3), and in the air surrounding the pool (28-390 µg/m3). These values were used to predict multi-pathway chronic daily intake (CDI), cancer risk (CR) and hazard index (HI). Oral and dermal CDI for swimmers were 2.4 × 10-6 and 2.0 × 10-8, respectively. The swimmers' inhalation CDI (1.9 × 10-3 mg/kg/day) was estimated to be sixfold higher than levels obtained for coaches (3.3 × 10-4 mg/kg/day). According to guidelines, the HI was acceptable, but CR exceeded the recommended limit for both, coaches (CR: 5.5 × 10-7-8.5 × 10-5; HI: 6.5 × 10-4-1 × 10-1) and swimmers (CR: 1.4 × 10-5-3.6 × 10-4 HI: 1.6 × 10-2-4.3 × 10-1). Our findings provide further support to the need to develop comprehensive guidelines to safeguard the health of individuals involved in elite swimming.

Comparison of DNA damages in blood lymphocytes of indoor swimming pool lifeguards with non-lifeguards athletes.

Chlorination has been used as a major disinfectant process for swimming pool water in many countries. The purpose of this study is to compare the DNA damage of the blood lymphocytes in indoor pool lifeguards with non-lifeguards athletes. We performed a study in which the participants were Gonabad's lifeguards. We chose 30 participants (15 male and 15 female) for each group. We collected vein blood samples from each participant in both exposed and control group. The lymphocytes were isolated from the whole blood by ficoll, and the cell viability was determined by the trypan blue. The alkaline Comet assay was also performed on lymphocytes in order to measure the DNA damage. All the parameters indicated that the DNA damage was significantly greater in lifeguards group than control group (p < 0.001). Also, the results revealed a statistically significant higher level of DNA damage in females as evident by an increase in the tail length (µm) [8.97 ± 4.21 for females as compared to 4.32 ± 1.33 for males (p = 0.001)], tail DNA (%) [4.18 ± 1.27 for females as compared to 3.14 ± 0.94 for males (p = 0.016)] and tail moment (µm) [0.68 ± 0.53 for females and 0.26 ± 0.14 for males (p = 0.010)]. There was also a significant positive correlation between DNA damage and the duration of work (P < 0.001).

Investigating the effects of design and management factors on DBPs levels in indoor aquatic centres.

Disinfection by-products (DBPs) in indoor swimming pool water and air have long been a critical human health risk concern. This study investigated the effects of several indoor swimming pool design and management factors (e.g. ventilation, water treatment, pool operations, pool type) on the concentrations of DBPs, such as trihalomethanes (THMs) and chloramines, in pool water and air. Two sampling campaigns, A and B, were carried out to measure the concentrations of DBPs under different conditions. In both campaigns, 46 pool water samples, seven tap water samples, and 28 ambient air samples were collected and analyzed. Regression models were also developed and validated for investigating the combined effects of design and management factors on total trihalomethanes (TTHM) and trichloramine. The model results show that pool water characteristics (e.g., total organic content, temperature, conductivity, pH and alkalinity) and management factors (e.g., the number of bathers and sprayers) have direct effects on DBP concentrations. Pool water characteristics such as UV absorbance, hardness, and oxidation-reduction potential and a management factor UV intensity have inverse effects on DBPs levels. Based on the correlation analysis, other factors such as fan speed, fresh air, pool age, and basin area were found to be correlated with the concentrations of individual THMs and trichloramine in both water and air. It was also observed that the concentration of THMs varies with pool type. It is note worthy that the effects of the number of sprayers was quantified for the first time. This study comprehensively assessed pool design and management factors and identified their effects on DBPs, providing indoor swimming pool facilities with useful information to control DBPs in the indoor swimming environment.

Indoor swimming pool environments and self-reported irritative and respiratory symptoms among lifeguards.

A web survey was conducted among 870 lifeguards (current and former) to assess the relationship between exposure to indoor swimming pool environments and respiratory health. Associations between respiratory symptoms and asthma with varying lengths of occupational exposure were assessed by multiple logistic regression. Lifeguards exposed more than 500 hours in the previous 12 months experienced more cough (adjustedOR = 2.54, IC95 % = 1.51-4.25), throat (aOR = 2.47, IC95 % = 1.44-4.24) and eye irritation (aOR = 4.34, IC95 % = 2.52-7.50) during this period than non-exposed lifeguards. Upper and lower respiratory symptoms while on duty were related to duration of lifetime exposure (> 500 days vs. ≤ 50 days: Upper aOR = 5.84, IC95 % = 3.60-9.50; Lower aOR = 2.53, IC95 % = 1.58-4.06). Physician-diagnosed asthma was high among lifeguards (23 %). Highly exposed asthmatic lifeguards (> 500 hours) over the previous 12 months had a significantly higher risk (aOR = 3.74, IC95 % = 1.39-10.02) of suffering from asthma attack(s) than non-exposed asthmatic subjects. Exposure to indoor swimming pool environments is related to respiratory symptoms among lifeguards.

Efectos negativos de los deportes acuáticos en el asma / Negative effects of water sports on asthma

El asma es una enfermedad crónica que consiste en la inflamación de las vías aéreas. Provoca tos, dolores de pecho y problemas para respirar. El asma todavía no tiene cura, pero sí es posible controlarlo. Aunque hay muchos estudios que hablan de los beneficios de la práctica deportiva en los pacientes asmáticos, este artículo de revisión expone que la actividad física, dependiendo de cuál sea la realizada y las condiciones en las que se realiza, puede tener efectos perjudiciales para los asmáticos. De hecho, la práctica de actividad física puede provocar por sí misma asma, es el denominado asma inducido por el ejercicio o AIE.

Asthma is a chronic disease that consists of inflammation of the airways. It causes coughs, chest pains and trouble breathing. Asthma still has no cure, but it is possible to control it. Although there are many studies that discuss the benefits of sports practice in asthmatic patients, this review article states that physical activity, depending on what is performed and the conditions under which it is performed, may have adverse effects for asthmatics. In fact, the practice of physical activity can cause asthma in itself, is the so-called exercise-induced asthma or EIA.

Occurrence and simulation of trihalomethanes in swimming pool water: A simple prediction method based on DOC and mass balance.

Trihalomethanes (THM) are the most typical disinfection by-products (DBPs) found in public swimming pool water. DBPs are produced when organic and inorganic matter in water reacts with chemical disinfectants. The irregular contribution of substances from pool visitors and long contact time with disinfectant make the forecast of THM in pool water a challenge. In this work occurrence of THM in a public indoor swimming pool was investigated and correlated with the dissolved organic carbon (DOC). Daily sampling of pool water for 26 days showed a positive correlation between DOC and THM with a time delay of about two days, while THM and DOC didn't directly correlate with the number of visitors. Based on the results and mass-balance in the pool water, a simple simulation model for estimating THM concentration in indoor swimming pool water was proposed. Formation of THM from DOC, volatilization into air and elimination by pool water treatment were included in the simulation. Formation ratio of THM gained from laboratory analysis using native pool water and information from field study in an indoor swimming pool reduced the uncertainty of the simulation. The simulation was validated by measurements in the swimming pool for 50 days. The simulated results were in good compliance with measured results. This work provides a useful and simple method for predicting THM concentration and its accumulation trend for long term in indoor swimming pool water.

An outbreak of swimming-pool related respiratory symptoms: An elusive source of trichloramine in a municipal indoor swimming pool.

BACKGROUND: Several members of a swimming club complained of respiratory symptoms associated with attending a municipal indoor swimming pool. Trichloramine, a volatile chlorination by-product and a potent respiratory irritant, was the most probable culprit, but the exact cause for its presence in excessive concentrations remained elusive. METHODS: Twenty-two competitive swimmers and six coaches were evaluated during the outbreak and nine swimmers and four coaches were re-evaluated one year later. Symptoms were recorded by non-standardized history taking; pulmonary function testing included spirometry, measurement of fraction of exhaled nitric oxide (FENO) and histamine provocation. Concentrations of trichloramine in air were measured repeatedly by the method of Héry. RESULTS: The most commonly reported symptoms consisted of cough (n=16), dyspnoea (n=13), tearing eyes (n=10) and blocked or runny nose (n=6). Mean FEV1% predicted was 109.1%. Mean FENO level was 19.7 ppb (higher than 25 ppb in 3 subjects). Airway hyperreactivity to histamine (PC20 ≤ 8 mg/ml) was detected in 22/26 subjects. Measured trichloramine concentrations in air exceeded the maximal concentration (WHO) of 0.5mg/m(3) four times between May and October 2011 and four times between January and March 2012. Polyamine compounds, present in glue used for repairing pipework, were identified as a probable external source of nitrogen resulting in increasing trichloramine concentrations. After the removal of the presumed cause of the excessive trichloramine concentrations, most subjects improved clinically, but several subjects remained symptomatic and had bronchial hyperreactivity. DISCUSSION: A high prevalence of airway hyperreactivity, accompanied by symptoms of upper and lower airways, was detected in swimmers who had been repeatedly exposed to high trichloramine concentrations. A glue containing polyamines, used to repair a pipework, was suspected to be the source of this excessive production of trichloramine.