Early life swimming pool exposure and asthma onset in children - a case-control study

Avoidance of Inhaled Pollutants and Irritants in Asthma from a Salutogenic Perspective

Much is known about the role of aeroallergens in asthma, but little is described about the damage caused by inhaled pollutants and irritants to the respiratory epithelium. In this context, the most frequent pollutants and irritants inhaled in the home environment were identified, describing the possible repercussions that may occur in the respiratory tract of the pediatric population with asthma and highlighting the role of the caregiver in environmental control through a salutogenic perspective. Searches were carried out in the MEDLINE/PubMed, Web of Science, Lilacs and Scopus databases for articles considered relevant for the theoretical foundation of this integrative review, in which interactions between exposure to pollutants and inhaled irritants and lung involvement. Articles published in the last 10 years that used the following descriptors were considered: air pollution; tobacco; particulate matter; disinfectants; hydrocarbons, fluorinated; odorants; chloramines; pesticide; asthma; and beyond Antonovsky's sense of coherence. Exposure to smoke and some substances found in cleaning products, such as benzalkonium chloride, ethylenediaminetetraacetic acid and monoethanolamine, offer potential risks for sensitization and exacerbation of asthma. The vast majority of the seven main inhaled products investigated provoke irritative inflammatory reactions and oxidative imbalance in the respiratory epithelium. In turn, the caregiver's role is essential in health promotion and the clinical control of paediatric asthma. From a salutogenic point of view, pollutants and irritants inhaled at home should be carefully investigated in the clinical history so that strategies to remove or reduce exposures can be used by caregivers of children and adolescents with asthma.

Overlooked inorganic DBPs in trichloroisocyanuric acid (TCCA) disinfected indoor swimming pool: Evidences from concentration, cytotoxicity, and human health risk

Trichloroisocyanuric acid (TCCA) is a popular disinfectant for swimming pools in China. However, the occurrence and importance of regulated disinfection byproducts (DBPs) in TCCA-disinfected swimming pools are less understood. This study analyzed 12 regulated DBPs (4 trihalomethanes (THMs), 5 haloacetic acid (HAAs), bromate, chlorate, and chlorite) in 85 swimming pool water samples and 17 input tap water samples from one swimming pool for 17 days continuously. Considering water temperature, pH, free chlorine, total chlorine, and urea, approximately 88%, 49%, 97%, 55%, and 97% of swimming pool water samples were within the water quality limits for China. Total concentrations of THMs, HAAs, and inorganic DBPs of 20.4-42.2, 82.0-229, and 100-729 μg/L in the swimming pool, and 16.6-28.3, 8.2-12.8, and 64.4-95.6 μg/L in the tap water, indicating inorganic DBPs are the dominant swimming pool and drinking water pollutants. Cancer risk values of regulated DBPs in swimming pools and input tap water are 2.7E-05 and 8.1E-05, respectively, and exceed the US EPA's threshold (1.0E-06). The non-cancer risk is below the US EPA's threshold. Following TCCA disinfection, the concentration and calculated cytotoxicity of regulated DBPs had a 3.6-fold and 1.9-fold increase, respectively. Inorganic DBPs contribute to the calculated concentration and cancer risks of DBPs in swimming pools and tap water at sufficient concentrations warranting regulation. This study provides data on 12 regulated DBPs in TCCA-disinfected indoor swimming pools, highlighting the importance of inorganic DBPs from evidences of concentration, cytotoxicity, and cancer risk for the first time.

Machine learning-driven identification of early-life air toxic combinations associated with childhood asthma outcomes

Air pollution is a well-known contributor to asthma. Air toxics are hazardous air pollutants that cause or may cause serious health effects. Although individual air toxics have been associated with asthma, only a limited number of studies have specifically examined combinations of air toxics associated with the disease. We geocoded air toxic levels from the US National Air Toxics Assessment (NATA) to residential locations for participants of our AiRway in Asthma (ARIA) study. We then applied Data-driven ExposurE Profile extraction (DEEP), a machine learning-based method, to discover combinations of early-life air toxics associated with current use of daily asthma controller medication, lifetime emergency department visit for asthma, and lifetime overnight hospitalization for asthma. We discovered 20 multi-air toxic combinations and 18 single air toxics associated with at least 1 outcome. The multi-air toxic combinations included those containing acrylic acid, ethylidene dichloride, and hydroquinone, and they were significantly associated with asthma outcomes. Several air toxic members of the combinations would not have been identified by single air toxic analyses, supporting the use of machine learning-based methods designed to detect combinatorial effects. Our findings provide knowledge about air toxic combinations associated with childhood asthma.

Health effects of exposure to chlorination by-products in swimming pools

Concerns have been raised regarding the potential negative effects on human health of water disinfectants used in swimming pools. Among the disinfection options, the approaches using chlorine-based products have been typically preferred. Chlorine readily reacts with natural organic matter that are introduced in the water mainly through the bathers, leading to the formation of potentially harmful chlorination by-products (CBPs). The formation of CBPs is of particular concern since some have been epidemiologically associated with the development of various clinical manifestations. The higher the concentration of volatile CBPs in the water, the higher their concentration in the air above the pool, and different routes of exposure to chemicals in swimming pools (water ingestion, skin absorption, and inhalation) contribute to the individual exposome. Some CBPs may affect the respiratory and skin health of those who stay indoor for long periods, such as swimming instructors, pool staff, and competitive swimmers. Whether those who use chlorinated pools as customers, particularly children, may also be affected has been a matter of debate. In this article, we discuss the current evidence regarding the health effects of both acute and chronic exposures in different populations (work-related exposures, intensive sports, and recreational attendance) and identify the main recommendations and unmet needs for research in this area.

Impact of habitual swimming on the success of lacrimal surgery

PURPOSE

To elucidate how factors associated with swimming affect the lacrimal ducts of swimmers.

STUDY DESIGN

Prospective, interventional cohort study, METHODS: Five hundred seventy four consecutive epiphora patients were surveyed via a questionnaire regarding details of their swimming-pool usage; i.e., frequency, swim-goggles' wear, and type of pool activity (i.e., swimming vs. waist-depth walking). In this cohort, all the swimmers over 20 years old with anatomical lacrimal duct obstruction underwent surgical reconstruction. The surgical success rates at 12-months postoperative were compared using multivariable logistic regression analyses between swimmer/non-swimmer patients, those with a history of high/low frequency of pool usage, and those with high/low amount of conjunctival contact with the swimming-pool water.

RESULTS

Of the patients with anatomical lacrimal duct obstruction, 6.4% were habitual swimmers; nasolacrimal duct obstruction was more common in the swimmers than in the non-swimmers' controls (89.1%/66.7%, P = 0.025). The success rate of lacrimal surgery for the swimmers with anatomical nasolacrimal duct obstruction was lower (60.6%) than of the non-swimmers (83.3%, P = 0.048). A receiver operating characteristic curve analysis of the frequency for the prediction of surgical failure showed that the threshold was 4 days/week. The success rate was statistically lower (26.7%) in the high-frequency swimmers compared to the low-frequency swimmers (88.9%, P = 0.037). However, no statistical difference in the high/low ocular surface contact to the swimming-pool water was observed (71.4%/57.7%, P = 0.56).

CONCLUSION

Habitual swimmers have a high risk of nasolacrimal-duct damage retrogradely from the nasal cavity that lowers lacrimal surgery's success rate.

Balneotherapy and hydrotherapy in chronic respiratory disease

Chronic respiratory diseases (CRD) belong to major noncommunicable diseases (NCD) targeted by World Health Organization (WHO) NCD Action Plan and United Nations (UN) Sustainable Development Goal (STG) 3.4 to achieve 30% decline of mortality by the year 2030. Strong evidence is now available in the literature for therapeutic aquatic exercise interventions in improving health status of chronic obstructive pulmonary diseases (COPD) patients. However, gym-based exercises can be difficult for patients with COPD who are mainly elderly and often have co-morbidities-such as severe arthritis and obesity-which may impair their ability to exercise at an adequate intensity. Besides improving respiratory function and health status in COPD, exercise in water helps overcoming patient's fears and promote socialization, contrasting the risk of depression, which is a major condition often associated with long term COPD condition. Susceptibility to respiratory infections plays a role in exacerbations of COPD. Sulphur-rich water inhalations improve muco-ciliary clearance, reduce inflammatory cytokines production and inflammatory mucosal infiltration, reduce elastase secretion by neutrophils, preserving elastic properties of pulmonary interstitium and thus facilitating expectoration. Repeated cold water stimulations in COPD also reduce frequency of infections. Finally, sauna bathing reduces the risk of pneumonia. On the other side, hydrotherapy/balneotherapy also help obesity control, which is one of the most difficult NCD risk factors to modify and consequently is an important component of the WHO preventive strategy to achieve STG 3.4. Along with high prevalence and mortality, CRD cause increasing pharmaceutical and hospital costs. In this perspective, Health Resort Medicine should not be ignored as a resource in the WHO NCD strategy and Universal Health Coverage, providing a multi-stakeholder platform (including the network of health resorts and their facilities) able to give a real help to the achievement of UN goal STG 3.4 by the year 2030.

Covariation amongst pool management, trichloramine exposure and asthma for swimmers in Norway

The association between asthma and exposure to the air in swimming facilities has been acknowledged. However, the variation in, long-term exposure to and management of the respiratory irritant trichloramine (NCl₃) is not well understood. In this study, 313 swimmers above 18 years of age licensed by the Norwegian Swimming Association answered a questionnaire about health and swimming. The prevalence of asthma amongst the most-exposed swimmers was 36%. Two facilities, those with the highest and lowest reported prevalence of asthma, were chosen for further investigation. For each facility, a one-week-long monitoring campaign was performed, during which pool management, air and water quality were investigated. The results of this study showed that time of day, occupancy and pool management affect the concentration of NCl₃, which ranged from 58 μg/m³ to 461 μg/m³. Furthermore, in one of the facilities, the concentration of CO₂ was measured to evaluate whether this contaminant could be used to predict the number of pool occupants as well as the concentration of NCl₃ in the air. The concentration of CO₂ was significantly correlated with occupancy level (ρ = 0.82, p = 0.01) and NCl₃ concentration (r = 0.80, p = 0.01). Furthermore, according to the random intercept model the concentration of CO₂ explained 52% of the variation observed in the air concentration of NCl₃. CO₂ sensors to control the air supply can help reduce the air concentrations of NCl₃ and balance the air supply based on occupancy level.

Impact of swimming school attendance in 3-year-old children with wheeze and rhinitis at age 5 years: A prospective birth cohort study in Tokyo

Background

In Japan, swimming school attendance is promoted as a form of therapy or as a prophylactic measure against asthma in young children. However, the putative beneficial effects have not been sufficiently verified.

Objective

The aim of the present study was to clarify whether or not swimming school attendance at age 3 years affects the onset and/or improvement of wheeze and rhinitis at age 5 years.

Methods

This study was a single-center, prospective, general, longitudinal cohort study (T-CHILD Study). Between November 2003 and December 2005, 1776 pregnant women were enrolled, and their offspring were followed up until age 5 years. Swimming school attendance at age 3 years and the presence of wheeze and/or rhinitis in the previous one year were examined using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. The relationship between swimming school attendance and wheeze and/or rhinitis was analyzed using multivariable logistic regression analysis.

Results

Data on the 1097 children were analyzed. At age 3 years, 126 (11.5%) children attended a swimming school, and at age 5 years, the prevalence of wheeze was 180 (16.4%) while that of rhinitis was 387 (35.3%). Swimming school attendance at age 3 showed no significant relationship with the development of either wheeze (aOR 0.83, 95% CI (0.43–1.60) or rhinitis (aOR 0.80, 95% CI (0.43–1.60) at age 5.

Conclusions

Swimming school attendance at age 3 years showed neither a preventive nor therapeutic effect on wheeze or rhinitis at age 5 years. There is thus no scientific evidence yet that swimming school attendance has a positive impact on the development of childhood wheeze or rhinitis.

Can CO2 sensors in the ventilation system of a pool facility help reduce the variability in the trihalomethane concentration observed in indoor air?

Volatile and hazardous compounds are formed during the chlorination of pool water. Monitoring components in the air, such as the four trihalomethanes; chloroform, dichlorobromomethane, dibromochloromethane and bromoform (tTHM), is challenging. Carbon dioxide (CO₂) sensors are used for controlling air quality in different buildings and can be installed in ventilation systems for continuous surveillance and monitoring purposes. However, such sensors are not used in indoor swimming facilities. In this study, samples of tTHM and CO₂ were collected and analysed, along with other air and water quality parameters such as combined chlorine, to evaluate whether CO₂ sensors could be used to explain the observed variability in the tTHM concentration in an indoor swimming facility and thereby reduce the exposure of individuals utilising the pool to tTHM. Random intercept models were built for the tTHM and CO₂ concentrations, respectively, and the results show that the relationships between combined chlorine in the water, CO₂ in the air and number of occupants explain 52% of the variability in tTHM. The correlation between occupancy and CO₂ concentration (ρ = 0.65, p ≤ 0.01) suggests that CO₂ sensors should be used so that the air supply corresponds to the demand of the users.

+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.

Exhaled nitric oxide as a marker of chlorine exposure in young asthmatic swimmers

BACKGROUND

Swimming is recommended for people with asthma. However, the inevitable exposure to chlorine and its disinfectant byproducts in indoor swimming pools could be responsible for bronchial inflammation and asthma development. Fractional exhaled nitric oxide (FeNO) is a noninvasive marker of airway inflammation that predicts asthma exacerbations.

OBJECTIVES

To evaluate pretraining and posttraining FeNO levels in young swimmers with asthma attending an indoor chlorinated pool compared with a set of healthy swimmers and to examine the potential risk of exposure to chlorine as a factor associated with bronchial inflammation.

METHODS

A total of 146 children (8-18 years old) constantly attending an indoor chlorinated swimming pool were enrolled. Spirometry and FeNO measurements were performed 30 minutes after their arrival at the pool and immediately after exercise. Pre-exercise and postexercise spirometric and FeNO levels were assessed in a random subgroup of 14 swimmers (10 with asthma and 4 without) who performed cardiopulmonary exercise testing.

RESULTS

Asthma was detected in 23 swimmers. In swimmers with asthma, preswimming FeNO values were significantly elevated compared with swimmers without asthma and their FeNO values measured before cardiopulmonary exercise testing. Postexercise FeNO values were significantly decreased by approximately one-third in healthy children and children with asthma in all sporting backgrounds. However, postswimming FeNO values remained significantly higher in swimmers with asthma compared with those without asthma. Forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC ratio values showed no significant difference before and after 2 types of activity.

CONCLUSION

Elevated FeNO levels before and after swimming were recorded in swimmers with asthma not observed in a different exercise field. The presence of chlorine in the indoor swimming pool seems to explain this finding.