BACKGROUND: The RNLI \"Float to Live\" campaign is based on research conducted in indoor pools with experienced open water swimmers. Study 1 investigated whether the RNLI \"Float to Live\" guidance would enable less experienced individuals to float in realistic open water conditions. Study 2 examined the separate effects of practice and coaching on floating competence.
METHODS: Study 1: Inexperienced water users conducted floats in either still, open fresh (n = 22) or open sea water (n = 13), followed by moving sea (n = 6) or fresh water (n = 5). Participants undertook three 2-min floats in still water wearing swimwear and one clothed float: 1) naïve; 2) following RNLI \"Float to live\" messaging; 3) individual float coaching; 4) simulated fall wearing summer clothing. In moving sea water, participants undertook two floats equivalent to Floats 3 and 4. In moving fresh water, participants undertook 3 floats: 1) naïve; 2) following \"defensive floating\" coaching; 3) simulated fall wearing summer clothing. Study 2: Two groups matched for skinfold thickness undertook three 2-min floats in a flume wearing swimwear. PRAC group (n = 12): 1) naïve; 2) following float practice; 3) float coaching; COACH group (n = 11) coaching followed by practice. Floating difficulty, confidence, competence, \"efficiency\" and perceived exertion were analysed using either a Friedman test or mixed model ANOVA.
RESULTS: In both fresh water and sea water, participants\' floating competence and confidence increased after viewing the RNLI messaging, it was further improved with individualised float coaching. The additional helpful instructions included: 1) \"head back with ears submerged\"; 2) \"relax\"; 3) \"breathe normally\"; 4) \"it is OK if your legs sink\"; 5) an accurate description of sculling for \"active\" floaters that needed it; 6) spread arms and legs for stability. The simulated fall with clothing did not impair floating competence. No difference in floating competence was seen between PRAC and COACH, though confidence may be increased sooner in COACH.
CONCLUSIONS: The RNLI float advice can be applied in realistic open water settings by less experienced water users. Additional content could be included to make the messaging even more effective.

This study aimed to compare performance, kinematic, and physiological variables between open water and pool swimming conditions in elite triathletes and to examine the associations between conditions on these variables. Fourteen elite triathletes (10 males and 4 females [23.4 ± 3.8 years]) performed two 1500-m swimming tests in open water and in a 25-m pool. Swimming speed, stroke rate (SR), length (SL) and index (SI), heart rate (HR), blood lactate concentrations [La-], and end-exercise oxygen uptake (EEV̇O2) were assessed in both conditions. Lower SL and SI and higher SR were obtained in open water compared with pool swimming (p < 0.05). Moreover, kinematic variables changed as a function of distance in both conditions (p < 0.05). No differences were found in the main physiological variables (HR, [La-], and EEV̇O2) between conditions. Respiratory exchange ratio presented lower values in open water than in pool conditions (p < 0.05), while time constant was higher in open water (p = 0.032). The fastest triathletes in open water obtained the best performance in the pool (r = 0.958; p < 0.001). All kinematic variables, HR and peak [La-] presented positive associations between conditions (r > 0.6; p < 0.05). Despite physiological invariance, triathletes and coaches should monitor specific open water training to adapt their swimming technique to the competitive environment.

BackgroundBy mid-September 2023, several event notifications related to cryptosporidiosis had been identified from different regions in Spain. Therefore, a request for urgent notification of cryptosporidiosis cases to the National Surveillance Network was launched.AimWe aimed at assessing the extent of the increase in cases, the epidemiological characteristics and the transmission modes and compared to previous years.MethodsWe analysed data on case notifications, outbreak reports and genotypes focusing on June-October 2023 and compared the results to 2016-2022.ResultsIn 2023, 4,061 cryptosporidiosis cases were notified in Spain, which is an increase compared to 2016-2022. The cumulative incidence was 8.3 cases per 100,000 inhabitants in 2023, sixfold higher than the median of 1.4 cases per 100,000 inhabitants 2016-2022. Almost 80% of the cases were notified between June and October. The largest outbreaks were related to contaminated drinking water or swimming pools. Cryptosporidium hominis was the most common species in the characterised samples (115/122), and the C. hominis IfA12G1R5 subtype, previously unusual in Spain, was detected from 76 (62.3%) of the 122 characterised samples.ConclusionsA substantial increase in cryptosporidiosis cases was observed in 2023. Strengthening surveillance of Cryptosporidium is essential for prevention of cases, to better understand trends and subtypes circulating and the impact of adverse meteorological events.

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OBJECTIVE: Data on drownings tend to underestimate mortality from this cause. The objective of this study was to describe fatal drownings recorded in Catalonia between 2019 and 2022 through forensic sources, present their characteristics, and assess the utility of this information for monitoring drowning mortality.
METHODS: A retrospective observational study based on the register of judicial deaths from the Institute of Legal Medicine and Forensic Sciences of Catalonia was carried out. Data on medicolegal aetiology, aquatic environment, age, gender, date of death, and municipality of origin were analysed. Statistical analysis was based on the comparison of proportions test based on Chi-square for categorical variables and the Mann Whitney U test for the comparison of numerical variables.
RESULTS: A total of 310 drownings were recorded, with a mean age of 57.2 years and a male predominance (77.1%). The majority of drownings were unintentional (71.3%), followed by suicides (15.5%), and cases of undetermined intent (12.6%). Compared to intentional drownings, unintentional and undetermined intent drownings had a higher percentage of males than females (81.2% vs. 56%, p<0.001), and fewer cases with Spanish nationality than foreign or undetermined nationality (60% vs. 92%, p<0.001). Middle-aged and older individuals accounted for the majority of deaths, but among unintentional drownings, those recorded in pools included significantly higher percentages of children and adolescents aged zero-fourteen years than those occurring in natural waters.
CONCLUSIONS: The results highlight the importance of drowning mortality in Catalonia and the need to strengthen preventive activities, especially for children and during episodes of intense heat. Medicolegal sources are useful for monitoring drowning mortality, but it would be beneficial if they incorporated information on variables such as place of residence and nationality.
OBJECTIVE: Los datos sobre ahogamientos tienden a subestimar la mortalidad por esta causa. El objetivo de este estudio fue describir los ahogamientos mortales registrados en Cataluña entre 2019 y 2022 a través de fuentes forenses, mostrar sus características y valorar la utilidad de esta información para monitorizar la mortalidad por ahogamientos.
METHODS: Se realizó un estudio observacional retrospectivo basado en el registro de muertes judiciales del Instituto de Medicina Legal y Ciencias Forenses de Cataluña. Se analizaron la etiología médico-legal, entorno acuático, edad, sexo, fecha de defunción y municipio de procedencia. El análisis estadístico se basó en la prueba de comparación de proporciones basada en Chi cuadrado para las variables categóricas y la prueba U de Mann Whitney para la comparación de variables numéricas.
RESULTS: Se registraron 310 ahogamientos mortales, con una edad media de 57,2 años y predominio masculino (77,1%). La mayoría fueron no intencionales (71,3%), seguidos por suicidios (15,5%) y casos de intencionalidad indeterminada (12,6%). Comparados con los ahogamientos intencionales, los no intencionales y de intencionalidad indeterminada incluyeron más hombres que mujeres (81,2% frente a 56%, p<0,001), y menos casos con nacionalidad española que extranjera o indeterminada (60% frente a 92%, p<0,001). Las personas de mediana y avanzada edad aportaron la mayoría de las defunciones pero, entre los ahogamientos no intencionales, los registrados en piscinas incluyeron más niños y adolescentes de cero-catorce años que los que tuvieron lugar en aguas naturales.
CONCLUSIONS: Los resultados prueban la importancia de los ahogamientos mortales en Cataluña y la necesidad de fortalecer las actividades preventivas, especialmente en la infancia y durante episodios de calor intenso. Las fuentes médico-forenses son útiles para monitorizar la mortalidad por ahogamientos, pero convendría que incorporaran variables como el lugar de residencia y la nacionalidad.

BACKGROUND: In this study, we use the media-based database of Beterem-Safe Kids Israel, to provide a 15-year review of unintentional fatal childhood drowning in Israel, between 2008 and 2022.
METHODS: It total, we identified 257 cases of child mortality due to drowning during this period.
RESULTS: Our results demonstrate a gradual rise in childhood mortality due to drowning, from 72 cases in 2008-2012, to 85 cases in 2013-2017, and to 100 cases in 2018-2022. Especially worth noting is the increase in childhood drowning in domestic swimming pools. We point to a link between low socioeconomic status and cases of drowning, showing that the risk of drowning extends beyond a mere matter of caregiver inattention. We recommend a series of regulatory and legislative steps to reduce fatal childhood drowning, including fencing built around domestic swimming pools, extending lifeguard activity hours, adding declared beaches, forming programs of safe behavior in water environments for adolescents, and establishing swimming lessons during the 2nd grade, for all populations. We further recommend that a special focus will be put in municipalities situated at the bottom of the socioeconomic index.

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.
METHODS: 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.
CONCLUSIONS: 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.

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.

Exposure to airborne disinfection by-products, especially trichloramine (TCA), could cause various occupational health effects in indoor swimming pools. However, TCA concentration measurements involve specialized analysis conducted in specific laboratories, which can result in significant costs and time constraints. As an alternative, modeling techniques for estimating exposures are promising in addressing these challenges. This study aims to predict airborne TCA concentrations in indoor swimming pools using a mathematical model, the well-mixed box model, found in the IHMOD tool, freely available on the American Industrial Hygiene Association website. The model\'s predictions are compared with TCA concentrations measured during various bather load scenarios. The research involved conducting 2-hr successive workplace measurements over 16- to 18-hr periods in four indoor swimming pools in Quebec, Canada. TCA concentrations were estimated using the well-mixed box model, assuming a homogeneous mixing of air within the swimming pool environment. A novel approach was developed to estimate the TCA generation rate from swimming pool water, incorporating the number of swimmers in the model. Average measured concentrations of TCA were 0.24, 0.26, 0.14, and 0.34 mg/m3 for swimming pools 1, 2, 3, and 4, respectively. The ratio of these measured average concentrations to their corresponding predicted values ranged from 0.51 to 1.30, 0.67 to 1.04, 0.57 to 1.14, and 0.68 to 1.49 for the respective swimming pools. In a worst-case scenario simulating the swimming pool at full capacity (maximum bathers allowed), TCA concentrations were estimated as 0.23, 0.36, 0.14, and 0.37 mg/m3 for swimming pools 1, 2, 3, and 4. Recalculated concentrations by adjusting the number of swimmers so as not to exceed the recommended occupational limit concentration of 0.35 mg/m3 gives a maximum number of swimmers of 63 and 335 instead of currently 80 and 424 for swimming pools 2 and 4, respectively. Similarly, for swimming pools 1 and 3, the maximum number of swimmers could be 173 and 398 (instead of the current 160 and 225, respectively). These results demonstrated that the model could be used to estimate and anticipate airborne TCA levels in indoor swimming pools across various scenarios.

The increasing demand for trichloroisocyanuric acid (TCCA) in swimming pool disinfection highlights the need to evaluate its applicability in terms of disinfection by-product (DBP) formation. Nevertheless, there is limited understanding of DBP formation and control during TCCA disinfection, particularly concerning the effects of various management parameters. This study aimed to fill this knowledge gap by comprehensively investigating DBP formation during TCCA chlorination, with a particular focus on assessing the contribution and interaction of influencing factors using Box-Behnken Design and response surface methodology. Results indicated that the concentrations of trichloroacetaldehyde, chloroform, dichloroacetic acid, trichloroacetic acid, and dichloroacetonitrile produced by TCCA disinfectant were 42.5%, 74.0%, 48.1%, 94.7% and 42.6% of those by the conventional sodium hypochlorite disinfectant, respectively. Temperature exhibited the most significant impact on chloroform formation (49%), while pH played a major role in trichloroacetaldehyde formation (44%). pH2 emerged as the primary contributor to dichloroacetic acid (90%) and trichloroacetic acid (93%) formation. The optimum water quality conditions were determined based on the minimum total DBPs (pH = 7.32, Temperature = 23.7 °C, [Cl-] = 437 mg/L). Chlorine dosage and contact time exhibited greater influence than precursor concentration on chloroform, dichloroacetonitrile, trichloroacetaldehyde, trichloroacetic acid, and total DBPs. Although the interaction between water quality parameters was weak, the interaction between disinfection operating parameters demonstrated substantial effects on DBP formation (8.56-19.06%). Furthermore, the DBP predictive models during TCCA disinfection were provided for the first time, which provides valuable insights for DBP control and early warning programs.