Outdoor Pools Research Articles

Radon Levels Measured at a Touristic Thermal Spa Resort in Montagu (South Africa) and Associated Effective Doses

Radon activity concentrations (in water and in air) were measured at 13 selected locations at the Avalon Springs thermal spa resort in Montagu (Western Cape, South Africa) to estimate the associated effective dose received by employees and visitors. A RAD-7 detector (DURRIDGE), based on alpha spectrometry, and electret detectors (E-PERM®Radelec) were used for these radon measurements. The primary source of radon was natural thermal waters from the hot spring, which were pumped to various locations on the resort, and consequently a range of radon in-water analyses were performed. Radon in-water activity concentration as a function of time (short term and long term measurements) and spatial distributions (different bathing pools, etc.) were studied. The mean radon in-water activity concentrations were found to be 205 ± 6 Bq L (source), 112 ± 5 Bq L (outdoor pool) and 79 ± 4 Bq L (indoor pool). Radon in-air activity concentrations were found to range between 33 ± 4 Bq m (at the outside bar) to 523 ± 26 Bq m (building enclosing the hot spring's source). The most significant potential radiation exposure identified is that due to inhalation of air rich in radon and its progeny by the resort employees. The annual occupational effective dose due to the inhalation of radon progeny ranges from 0.16 ± 0.01 mSv to 0.40 ± 0.02 mSv. For the water samples collected, the Ra in-water activity concentrations from samples collected were below the lower detection limit (~0.7 Bq L) of the γ-ray detector system used. No significant radiological health risk can be associated with radon and progeny from the hot spring at the Avalon Springs resort.

Study on a Polish peat bog “Rucianka” as a source of yeast strains capable of effective phenol biodegradation

Sodium hypochlorite (NaClO) is the most commonly used disinfectant in pool treatment system. Outdoor pools usually suffer from the strong sunlight irradiation which degrades the free chlorine rapidly. In addition, more pools start to adopt the recirculation of swimming pool water, which intensifies the disinfection by-product (DBP) accumulation issue. Given these potential drawbacks of using NaClO in the tropical environment, two alternative organic-based disinfectants, trichloroisocyanuric acid (TCCA, C3Cl3N3O3) and bromochlorodimethylhydantoin (BCDMH, C5H6BrClN2O2), were investigated and compared to NaClO in terms of their self-degradation and the formation of DBPs, including trihalomethanes (THMs) and haloacetic acids (HAAs), under simulated tropical climate conditions. The result reveals that halogen stabilizer, TCCA, had the advantages of slower free chlorine degradation and lower DBP concentration compared to NaClO, which makes it a good alternative disinfectant. BCDMH was not recommended mainly due to the highly reactive disinfecting ingredient, hypobromous acid (HBrO), which fails to sustain the continuous disinfection requirement. Total disinfectant dosage was the main factor that affects residual chlorine/bromine and THM/HAA formation regardless of different disinfectant dosing methods, e.g. shock dosing (one-time spiking) in the beginning, and continuous dosing during the whole experimental period. Two-stage second-order-kinetic-based models demonstrate a good correlation between the measured and predicted data for chlorine decay (R2 ≥ 0.95), THM (R2 ≥ 0.99) and HAA (R2 ≥ 0.83) formation. Higher temperature was found to enhance the DBP formation due to the temperature dependence of reaction rates. Thus, temperature control of pools, especially for those preferring higher temperatures (e.g. hydrotherapy and spa), should take both bather comfort and DBP formation potential into consideration. It is also observed that chlorine competition existed between different precursors from natural organic matters (NOM) in filling water and body fluid analogue (BFA). Among the composition of BFA, uric acid, citric acid and hippuric acid were found to be the main precursors for HAA formation.

Presence and select determinants of organophosphate flame retardants in public swimming pools

The occurrence of five organophosphate flame retardants (PFRs) consisting of tributyl phosphate (TNBP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCIPP), tris(1.3-dichloro-2-propyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP) in swimming pools were investigated. Fifteen chlorinated public swimming pools were sampled, including indoor pools, outdoor pools and spa pools. The analyses were carried out using isotope dilution gas chromatography tandem mass spectrometry. All five PFRs were detected in swimming pool waters with concentrations ranging from 5–27ng/L (TNBP), 7–293ng/L (TCEP), 62–1180ng/L (TCIPP), 10–670ng/L (TDCIPP) and 8–132ng/L (TPHP). The concentrations of PFRs were generally higher in indoor swimming pools compared to outdoor swimming pools. In municipal water supplies, used to fill the swimming pools in three of the sampling locations, the five PFRs were all below the limit of quantifications, eliminating this as the source. Potential leaching of PFRs from commonly used swimming equipment, including newly purchased kickboards and swimsuits was investigated. These experiments revealed that PFRs leached from swimsuits, and may be a source of PFRs in swimming pools. A quantitative risk assessment revealed that the health risk to PFRs via swimming pools was generally low and below commonly applied health risk benchmarks.

Not Cured … But Improved

Not Cured … But Improved

Potential risks of TiO2 and ZnO nanoparticles released from sunscreens into outdoor swimming pools

The potential risks of nanoparticles (NPs) in sunscreens being released into swimming water were evaluated by a series of laboratory experiments simulating the fate and transport of NPs in outdoor swimming pools. NPs released from sunscreen-applied skin were estimated using pig skins covered with five different commercial sunscreens containing TiO2, ZnO, or both at various concentrations. Assuming that the swimming water treatment processes consisted of filtration, UV irradiation, heating, and chlorination, possible removal of the released NPs by each process was estimated. Generation of hydrogen peroxide (H2O2) by the NPs under sunlight and after UV photochemical treatment were measured, and the H2O2 concentration possibly present in the swimming pool was calculated based on some specific scenarios of operating an outdoor swimming pool. It was found that a significant amount of the NPs in sunscreens could be released into the swimming water, and accumulate during circulation through the treatment system. However, the concentration of H2O2 possibly present in the swimming pool should be below the level at which an adverse effect to bathers is concerned.

An insight of disinfection by-product (DBP) formation by alternative disinfectants for swimming pool disinfection under tropical conditions

Sodium hypochlorite (NaClO) is the most commonly used disinfectant in pool treatment system. Outdoor pools usually suffer from the strong sunlight irradiation which degrades the free chlorine rapidly. In addition, more pools start to adopt the recirculation of swimming pool water, which intensifies the disinfection by-product (DBP) accumulation issue. Given these potential drawbacks of using NaClO in the tropical environment, two alternative organic-based disinfectants, trichloroisocyanuric acid (TCCA, C3Cl3N3O3) and bromochlorodimethylhydantoin (BCDMH, C5H6BrClN2O2), were investigated and compared to NaClO in terms of their self-degradation and the formation of DBPs, including trihalomethanes (THMs) and haloacetic acids (HAAs), under simulated tropical climate conditions. The result reveals that halogen stabilizer, TCCA, had the advantages of slower free chlorine degradation and lower DBP concentration compared to NaClO, which makes it a good alternative disinfectant. BCDMH was not recommended mainly due to the highly reactive disinfecting ingredient, hypobromous acid (HBrO), which fails to sustain the continuous disinfection requirement. Total disinfectant dosage was the main factor that affects residual chlorine/bromine and THM/HAA formation regardless of different disinfectant dosing methods, e.g. shock dosing (one-time spiking) in the beginning, and continuous dosing during the whole experimental period. Two-stage second-order-kinetic-based models demonstrate a good correlation between the measured and predicted data for chlorine decay (R2 ≥ 0.95), THM (R2 ≥ 0.99) and HAA (R2 ≥ 0.83) formation. Higher temperature was found to enhance the DBP formation due to the temperature dependence of reaction rates. Thus, temperature control of pools, especially for those preferring higher temperatures (e.g. hydrotherapy and spa), should take both bather comfort and DBP formation potential into consideration. It is also observed that chlorine competition existed between different precursors from natural organic matters (NOM) in filling water and body fluid analogue (BFA). Among the composition of BFA, uric acid, citric acid and hippuric acid were found to be the main precursors for HAA formation.

현대 일본 중학교 건축의 계획특성에 관한 연구

본 연구는 국내 중학교 건축 계획 시 참조점을 구하기 위해 관련 연구가 부족했던 일본의 중학교 건축을 대상으로 그 계획특성을 살펴보았다. 이를 위해 1990년대 이후 준공된 14개 학교들을 선별해 이들을 대상으로 교육 및 생활공간, 기타 주요 공간 등의 영역별 계획특성을 분석하였다. 분석대상 학교들의 계획특성을 정리하면 다음과 같다. 1) 분석대상 학교들은 학교 운영방식에 따라 교과교실형 학교와 특별교실형 학교로 크게 구분할 수 있는데 이에 따라 가장 기본적인 공간이 되는 교육 및 생활공간의 계획특성에서 차이가 나타난다. 2) 교과교실형 학교는 교과교실, 홈베이스, 미디어 스페이스, 교사공간 등의 요소로 교육 및 생활공간이 구성되며 홈베이스와 교과교실과의 인접여부에 따라 교실 부속형과 독립형의 두 가지 유형으로 크게 구분된다. 3) 특별교실형 학교는 학급교실과 다목적 공간으로 교육 및 생활공간이 구성되는데, 다목적 공간과 학급교실이 직접 연결되어 있는 유형과 분리되어 있는 두 가지 유형으로 구분된다. 4) 특별교실은 지역개방과 과목별 특성을 강조할 수 있는 계획특성이 나타나며 부속 공간들의 연계로 공간의 분화특성이 나타난다. 5) 도서실은 개별실이 아닌 컴퓨터실, 시청각실, 다목적 홀 등과 연계된 복합구성으로 계획되며 벽으로 구획하지 않고 개방적으로 구성하는 경향이 강하다. 6) 체육시설로는 옥내 체육관이 기본적으로 설치되며 이와 함께 무도장, 옥외 수영장 등의 설치 빈도가 높다. 이들은 체육수업뿐만 아니라 방과 후 활동을 지원하기 위해 설치된 측면도 크다. 7) 테라스, 발코니, 외부계단 등의 적극적인 계획을 통해 외부공간을 입체적으로 확보하고 있으며 이들이 다양한 기능을 가지도록 계획하고 있다. This study reviewed the planning characteristics of contemporary Japanese middle school architecture on which related studies are insufficient, aiming to obtain new ideas for planning Korean middle school facilities. Fourteen case schools built after 1990s were selected and analyzed. They were divided into learning-living space and other major spaces. The planning characteristics of the case schools are summarized as follows 1) The case schools were classified into two categories, departmentalized classroom type (D type) and usual with variation type (UV type) by school system. These categories can also be the classification standard for basic architectural characteristics in learning and living space of case schools. 2) D type case schools have departmentalized classrooms, home base, media space and teacher's space for learning-living space. D type case schools are divided into 'attached-to-classroom type' and 'separate type' depending on the adjacency of the home base and departmentalized classroom. 3) UV type case schools have multipurpose space around the classroom for learning-living space and can be divided into two types, i.e., 'directly adjacent' and 'separate', depending on the connectivity to classroom of multipurpose room. 4) Specialized classrooms are designed to have the openness to the public and the own characteristics of school subjects strengthened and show the spatial differentiation with connected ancillary spaces. 5) Libraries are designed as complex zones grouped with computer labs, audio visual rooms and multipurpose halls not as a single room and as open plan not with a closed wall. 6) The gymnasium is the basic sports facility with a martial arts room and outdoor pool, which are for after-school activities as well as physical education class. 7) The terrace, balcony and outdoor stairs are frequently used architectural vocabularies as diverse outdoor spaces with a variety of functions.

Can you really swim? Validation of self and parental reports of swim skill with an inwater swim test among children attending community pools in Washington State

BackgroundDrowning is the second leading cause of unintentional injury death among US children. Multiple studies describe decreased drowning risk among children possessing some swim skills. Current surveillance for this protective...

Characteristic Features of the Water-Treatment System Design for Outdoor Pools in the Urals

Outdoor pools for all-season use in the Urals make it possible to develop optimal conditions for population health promotion and recreation. The operational reliability of a pool involves designing and building of the pool basin structure as well as the modern water treatment that enables conditioning and purification of water from all kinds of contaminants received by water from the external sources and customers including water disinfection. This is achieved by means of development of the water recycling system with the use of filters loaded by the local filtering materials, the use of the combined water disinfection by liquid chlorine-containing reagents and by ozonation, water heating to desired temperatures in summer and in winter. The filter scouring water is intended for car wash after suitable decontamination. Reduction of water discharge for replenishing of the water-treatment system is possible thanks to ozonation and allowance for time estimation of operative and idle periods. These measures decrease the construction costs for such objects and shorten the payback period, attract investors for the project implementation.

Dynamic Simulation of Outdoor Swimming Pool Solar Heating

This paper presents a dynamic model of a “passive” solar heating system composed by horizontal solar flat collectors coupled to an outdoor swimming pool. The numerical model has been developed by using the Matlab/Simulink environment and it allows to predict on a hourly basis the thermal energy collected by the solar panels, the inlet/outlet collector working fluid temperature, the pool water temperature and the system efficiency. As a case study, three different pools characterized by different dimensions and three different flat solar collectors (unglazed, glazed and evacuated collectors) have been considered. The Simulink model allows to estimate the warm-up period of the swimming pool as a function of the characteristics of the pool and of the solar collectors. It has been demonstrated that, by using the model, the designer can make the optimal sizing of the solar heating system in order to obtain a water pool temperature ranging within a fixed interval. The results demonstrate that unglazed collectors are appropriate for this kind of use and evacuated collectors can be useful just in case of very big swimming pools in order to reduce the absorbing area of the solar panels.

Front-crawl stroke descriptors variability assessment for skill characterisation

ABSTRACTThe goal of this article is to characterise front-crawl swimming skill based on variability pattern of technique descriptors. Nine national level and nine recreational swimmers performed three 300 m trials in a 50 m outdoor pool, at 70%, 80% and 90% of their front-crawl 400 m personal best time. Using wearable inertial measurement units (IMUs) and validated algorithms we assessed the variability of technique descriptors at each arm cycle (139 ± 17 per trial). We calculated the duration of pull, push and non-propulsive phases, index of coordination (IdC), stroke length, stroke rate and intra-cyclic velocity variation. To track intra-trial technique variability, we calculated the Cauchy index to quantify the stability of multidimensional technique descriptors in space–time. Skilled swimmers, having access to divers motor solutions, achieved significantly higher velocities at similar intensities and similar IdC (P < 0.01) with more stable motor pattern (smaller Cauchy index). Besides, the similarity of intra-cyclic velocity variation at different intensities denotes that skilled swimmers used a wider dynamic range of velocity. We also introduced cycle velocity variation as a new metric of propulsive pattern repeatability and showed cycle velocity variation changes is correlated to the Cauchy index (rx,y = 0.72, P < 0.01). These findings indicate that IdC can be used as a predictor of performance only when swimmers of homogeneous expertise level are studied and suggest the scrutiny of both intra-cyclic velocity variation and cycle velocity variation as a requisite to study the motor adaptations of the swimmer in facing new constraints.

Variability in 24 hour excretion of cyanuric acid: implications for water exposure assessment.

Cyanuric acid (CYA) excretion in urine has been used to estimate the volume of water ingested during swimming and other recreational activities in outdoor pools containing this chemical. These estimates of water ingestion are based on the assumption of 100% excretion within 24 hours, but the supporting evidence for this is scant. While adapting this methodology to investigate other water ingestion scenarios, we observed a high degree of variability in cyanuric acid excretion among experimental subjects, with over 25% of individuals excreting less than 80% of an ingested dose. Use of cyanuric acid to measure inadvertent water ingestion may be a valuable tool to generate data for health risk assessment of non-potable water sources, but our observations indicate that this technique carries an inherent degree of underestimation that should be taken into account when calculating water exposure.

The phoenix series large-scale methane gas burner experiments and liquid methane pool fires experiments on water

This paper summarizes a series of large-scale outdoor and indoor LNG pool fire experiments conducted at Sandia National Laboratories in Albuquerque, New Mexico. Two outdoor LNG spills on water with resulting pool fires of 21 m and 56 m in diameter were conducted to improve hazard predictions by obtaining measurements of flame height, smoke production, and burn rate. The experimental data indicates that LNG pool fires on water display different behavior than those on land by producing less smoke. Surface emissive powers of up to 286 kW/m2, flames heights of up to 146 m, and burn rates of about 0.147 kg/m2 s were measured. Discussion is provided on the observed behavior of the two outdoor tests with regards to smoke production, wind effects, and hydrate production. The large-scale indoor experiments used a 3-m diameter gas burner with methane fuel to assess flame height to fire diameter ratios as a function of non-dimensional heat release rates for extrapolation to large-scale LNG fires. A flame height correlation was developed from this data.

Biologically active carbon filtration for haloacetic acid removal from swimming pool water

A biologically activate carbon (BAC) filter was continuously operated on site for the treatment of haloacetic acids (HAAs) in an outdoor swimming pool at an average empty bed contact time (EBCT) of 5.8min. Results showed that BAC filtration was a viable technology for direct removal of HAAs from the pool water with a nominal efficiency of 57.7% by the filter while the chlorine residuals were 1.71±0.90mg/L during the study. THMs and TOC were not removed and thus were not considered as indicators of the effectiveness of BAC filtration. Increased EBCT in the range of 4.5 and 6.4min led to improved HAA removal performance, which could be best fit by a logarithmic regression model. BAC filtration also affected the HAA speciation by removing more dichloroacetic acid (DCAA) than trichloroacetic acid (TCAA), resulting in a lower ratio of DCAA/TCAA in the filtered effluent. However, the observation of an overall constant ratio could be attributable to a complex formation and degradation mechanism occurring in swimming pools.

Occurrence and human exposure of parabens and their chlorinated derivatives in swimming pools.

As an emerging group of endocrine-disrupting chemicals, parabens have attracted growing attention due to their potential effects on human health. In the present study, the occurrence and distribution of eight parabens, four chlorinated parabens, and their common hydrolysis product, p-hydroxybenzoic acid (PHBA), were investigated in 39 swimming pools in Beijing, China. Methyl paraben and propyl paraben were the predominant compounds in swimming pools, accounting for 91.2 % of the total parabens. It is noteworthy that octyl paraben, a paraben with longer chain, was firstly detected in this study. There were several factors affecting the levels of parabens among the 39 swimming pools. The concentrations of parabens and chlorinated derivatives detected in indoor pools (144 ng L(-1)) were roughly 20-fold higher than those in outdoor pools (6.78 ng L(-1)). Hotel pools appear to present higher level of target compounds (361 ng L(-1)) than that in health club (228 ng L(-1)), municipal (130 ng L(-1)), school (75.6 ng L(-1)), and community pools (63.0 ng L(-1)). Moreover, the level of these compounds in pools during weekends (174 ng L(-1)) was much higher than that during weekdays (52.3 ng L(-1)). The dynamics of target compounds were also investigated to provide a general trend of the level of parabens in a school indoor swimming pool during a 14-week period. Human exposure assessment was conducted to estimate the potential risk of exposure to parabens and their chlorinated derivatives in swimming pools. Considering the total exposure dose of multiple parabens, human exposure to parabens from the water of swimming pools is negligible. However, the threat of these parabens to children in swimming pool should be concerned.

20 years of exploitation of the Yarragadee aquifer in the Perth Basin of Western Australia for direct-use of geothermal heat

Aquifers in the Perth Metropolitan Region of Western Australia have been explored and exploited for water supply since the late 19th century. Throughout the early 20th century, the availability of warm groundwater from the Yarragadee confined aquifer at relatively shallow depths was popular with laundries, public baths and for industrial applications but it was not until 1997 that the first direct-use geothermal project for bathing and swimming was implemented. By 2016, a dozen commercially successful geothermal schemes will use low enthalpy geothermal water supplies from the Yarragadee aquifer at depths ranging from 750 to 1150m for heating leisure centres, building air and outdoor pools. With distributed heat estimated to more than 110×103GJ per year and up to 180×103GJ when considering projects currently at construction stage but not yet commissioned, Perth currently has the biggest concentration of operating geothermal direct-use projects in Australia. The development of geothermal projects in Perth was made possible by early achievements pioneered by designers from the groundwater industry. This paper presents the hydrogeological setting of the Yarragadee aquifer which is the main geothermal resource in Perth, the well and surface heat exchanger design criteria, the economic and environmental considerations, and the best practices and circumstances that led to the 100% success rate of direct-use geothermal projects in Perth.

Concentration levels of disinfection by-products in 14 swimming pools of China

Swimming has become a popular exercising and recreational activity in China but little is known about the disinfection by-products (DBPs) concentration levels in the pools. This study was conducted as a survey of the DBPs in China swimming pools, and to establish the correlations between the DBP concentrations and the pool water quality parameters. A total of 14 public indoor and outdoor pools in Beijing were included in the survey. Results showed that the median concentrations for total trihalomethanes (TTHM), nine haloacetic acids (HAA9), chloral hydrate (CH), four haloacetonitriles (HAN4), 1,1-dichloropropanone, 1,1,1-trichloropropanone and trichloronitromethane were 33.8, 109.1, 30.1, 3.2, 0.3, 0.6 μg·L−1 and below detection limit, respectively. The TTHM and HAA9 levels were in the same magnitude of that in many regions of the world. The levels of CH and nitrogenous DBPs were greatly higher than and were comparable to that in typical drinking water, respectively. Disinfection by chlorine dioxide or trichloroisocyanuric acid could substantially lower the DBP levels. The outdoor pools had higher TTHM and HAA9 levels, but lower trihaloacetic acids (THAA) levels than the indoor pools. The TTHM and HAA9 concentrations could be moderately correlated with the free chlorine and total chlorine residuals but not with the total organic carbon (TOC) contents. When the DBP concentration levels from other survey studies were also included for statistical analysis, a good correlation could be established between the TTHM levels and the TOC concentration. The influence of chlorine residual on DBP levels could also be significant.

Beliefs about using an outdoor pool: Understanding perceptions of place in the context of a recreational environment to improve health

Following the Reasoned Action Approach, an online survey of 74 outdoor pool users illustrates how a theory-based behavioral analysis can be used to identify people׳s perceptions of a place in their environment. Regression analysis of close-ended data demonstrated that intention “to use the outdoor pool next summer season” was predicted (R2=.636, p<.0001) from the weighted combination of attitude (β=.663, p<.0001) and perceived control (β=.197, p<.05). The importance of attitude suggests that use can be encouraged by addressing advantages. The content analysis of open-ended elicitation data revealed that users believed that pool use provides physical, social, and emotional advantages and could be made easier by modifying facility parameters. Implications for promoting and designing public health spaces to attract users to aquatic environments and to improve health are discussed.

If we offer it, will children buy it? Sales of healthy foods mirrored their availability in a community sport, commercial setting in Alberta, Canada.

Community sports settings are often sources of unhealthy foods for children. Many managers in these settings are reluctant to increase availability of healthy food options because they perceive that healthy foods are not profitable. This study assessed the independent contribution of increased availability of healthy foods to their sales in a community sport, commercial context. Change in revenues per patron was also examined. The availability of healthy items was increased from 9.1% at baseline (35 days) to 25.0% during the intervention period (40 days), returning to 9.1% postintervention (6 days). Purchases of all patrons who bought foods/beverages (n=17,262 items sold) from two concessions at an outdoor community pool were assessed from baseline to postintervention. Chi-square analyses assessed differences in the proportion of healthy and unhealthy items sold, as well as in the proportion of total revenues per patron across periods. A trained observer also recorded qualitative observations pertaining to a subset of patrons' (n=221) dietary behaviors and activities. Healthy items represented 7.7%, 22.7%, and 9.8% of sales during the preintervention, intervention, and postintervention periods, respectively (p<0.01). Sales of healthy beverages exceeded sales of all other product types. The proportion of total revenues per patron did not differ by period. Food availability was an important environmental determinant of food purchasing behaviors in this community commercial context, given that sales of healthy foods closely mirrored their availability. Increased availability of healthy foods in community and commercial settings is important because concurrent changes within multiple environments will be required to improve children's dietary behaviors.

Down Under: confessions of a vagrant registrar

While working at Queen Square as a neurology trainee in 2013, I became friends with a number of Australian and New Zealand Association of Neurologists (ANZAN) Fellows who, over the...