scholarly journals The effectiveness of ozone-chlorine treatment for reducing chloramine concentration compared to chlorine treatment in swimming pools and whirlpools

2014 ◽  
Author(s):  
Derrick Mah ◽  
BCIT School of Health Sciences, Environmental Health ◽  
Helen Heacock
Keyword(s):  
Swimming Pool ◽  
Ozone Treatment ◽  
Concentration Limit ◽  
Upper Respiratory Tract ◽  
Swimming Pools ◽  
Chlorine Disinfection ◽  
Two Samples ◽  
Significant Difference ◽  
Analysis System ◽  
By Products

  Objectives: Chloramines are by-products of chlorine disinfected swimming pools and are hazardous to people if chloramines evaporate into the air. There is evidence that chloramines cause upper respiratory tract and eye irritation. It was suspected that ozone treatment in addition to chlorine disinfection will reduce chloramine levels in the pool. The following study compared chloramine concentration in a strictly chlorine disinfected swimming pool and whirlpool (C.G. Brown) in Burnaby, BC with an ozone-chlorine disinfected swimming pool and whirlpool (Killarney) in Vancouver, BC. The study also compared each pool and whirlpool to the 1.0 mg/L combined chlorine concentration limit in the B.C. Pool Regulation. Methods: Chloramine concentrations were determined by using a Hach Pocket Colorimeter 2 Analysis System which used a DPD method of analysis. Chloramine was determined by subtracting total chlorine by the free chlorine. Thirty pool water samples were analyzed based on two samples per pool per day for fifteen days. A two sample t-test was used to compare the ozone-chlorine treated pools with the chlorine only treated pools using the Mann-Whitney U test. A z-test was used to compare all types of swimming pools and whirlpools to the 1.0 mg/L limit. Results: The chloramine concentration in both the ozone-chlorine disinfected swimming pool and whirlpool was not statistically significantly lower than in the chlorine disinfected swimming pool (p=0.263597) and whirlpool (p=0.523672). Both types of swimming pools were found to be statistically significantly greater than the 1.0 mg/L chloramine limit (p=0.000023 in the chlorine pool and p=0.00001 for the ozone-chlorine pool). Similarly, both types of whirlpools were determined to be statistically significantly greater than the 1.0 mg/L chloramine limit (p=0.000001 for the chlorine pool and p=0.000001 for the ozone-chlorine pool). Conclusion: It was determined that there was no difference between ozone chlorine treated pools and chlorine only treated pools. Environmental Health Officers can suggest other forms of secondary treatment instead of ozone since there is no significant difference compared to chlorine only treated pools in reducing chloramine concentrations. This information is also beneficial for pool operators because they can increase their flow rates for pools that use ozonation or strictly chlorination relative to what they were originally designed for.  

scholarly journals Contrasting the effectiveness of chloramines reduction in indoor swimming pools disinfected by ozone versus UV

2015 ◽  
Author(s):  
Iris Chan ◽  
BCIT School of Health Sciences, Environmental Health ◽  
Bobby Sidhu
Keyword(s):  
Health Hazard ◽  
Free Chlorine ◽  
Ozone Treatment ◽  
Secondary Treatment ◽  
Swimming Pools ◽  
Significant Difference ◽  
The Mean ◽  
Analysis System ◽  
Pool System ◽  
By Products

  Objectives: Chloramines are disinfection by-products that are produced between chlorine and contaminants in the pool. Exposures to chloramines at high levels or for extended durations have been found to cause mucous membrane irritations and respiratory distress in humans. To reduce chloramines production, secondary treatment in the form of UV and ozone are used in newer indoor swimming pools. This study aimed to examine whether there is a difference between UV and ozone treatment in their effectiveness in reducing chloramines in indoor pools. Killarney leisure pool and whirlpool, which utilized ozone treatment, as well as Hillcrest leisure pool and whirlpool, which utilized UV treatment, were studied. Methods: Hach Pocket Colorimeter 2 Analysis System which used a DPD method of analysis was used to determine concentrations of free chlorine and total chlorines. Concentrations of chloramines were calculated by subtracting the concentration of free chlorine from total chlorine. Thirty pool water samples for each type of pool system were analyzed on random days in the afternoons of January and February, 2015. A two sample t-test was used to compare the chloramines concentrations of the whirlpools; while a Mann-Whitney U test was used to compare the chloramines concentrations of the leisure pools. Results: There was a statistically significant difference between the mean chloramines concentration of the UV-treated whirlpool and that of the ozone-treated whirlpool (p = 0.00854). However, there was not a statistically significant difference between the mean chloramines concentration between the UV treated leisure pool and that of the ozone treated leisure pool (p = 0.882048). Conclusions: It was determined that UV was more effective than ozone in reducing chloramines concentrations in indoor public whirlpools. Therefore, in order to choose a treatment that leads to the greatest reduction of health hazard posed to pool patrons, UV is preferred. Whirlpools that intend to adopt secondary treatment may consider UV.  

scholarly journals Using Sodium Hypochlorite as the Main Disinfectant in the Swimming Pool of National Technical University Sports Complex

2021 ◽  
Vol 6 (1) ◽  
pp. 168-172
Author(s):  
K. V. Solomakha ◽  
◽  
S. I. Harkavyi
Keyword(s):  
Sodium Hypochlorite ◽  
Leisure Activities ◽  
Statistical Processing ◽  
Short Review ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Advantages And Disadvantages ◽  
National Technical ◽  
Significant Difference ◽  
Technical University

This article is about the importance of sanitary and hygienic examination of water complexes, in particular, swimming pools and water parks. There is an increasing demand for visiting such water complexes in Ukraine, both for sports activities and for leisure activities. The focus of this article is on the sanitary and hygienic examination and survey of pool water, which is treated with sodium hypochlorite (obtained by chemical way). Material and methods. The studies were carried out for 10 weeks, including a series of water samples, which were taken during the quarantine period, when swimmers were prohibited from visiting the pool. This situation made possible to make a comparative hygienic assessment of the effect of workload on the water condition in the pool and the effectiveness of disinfection. There was also a short review and characteristics of hypochlorite A, which was obtained in chemical way, its advantages and disadvantages as a disinfectant. The article analyzes the data obtained during the sanitary and hygienic survey of the pool of the swimming pool of the national technical university, their statistical processing, and comparison with the current regulatory documents of Ukraine and some other states. The data obtained in the course of a series of studies indicated a significant human influence on the state of water in the pool, which once again indicates the importance of health education of the population and visitors in swimming pools and water parks, in particular, the need to take a shower before swimming, after using the toilet, etc.; the need for training the right culture of visiting different water objects. Particular attention should be paid to swimming pools frequented by children, as they often do not have sufficient hygiene skills, or due to age cannot constantly monitor urination, so, as a rule, it`s an acute issue of large amounts of chloramines in swimming pools for children. Conclusion. In particular, a statistically significant difference was obtained in terms of ammonia and ammonium ions (in total), which indicated a significant influence of visitors on this parameter. And, as you know, organic impurities (sweat, urine, cosmetics remains etc.) that get into the water together with the swimmers, react with chlorine and form chloramines, which can negatively affect the health of both the visitors and the staff. This must be taken into account while changing the workload on the pool and choosing the dose of disinfectant

scholarly journals An exploration of disinfection by-products formation and governing factors in chlorinated swimming pool water

2018 ◽  
Vol 16 (6) ◽  
pp. 861-892 ◽  
Author(s):  
Huma Ilyas ◽  
Ilyas Masih ◽  
Jan Peter van der Hoek
Keyword(s):  
Water Quality ◽  
Dichloroacetic Acid ◽  
Swimming Pool ◽  
Residual Chlorine ◽  
Swimming Pools ◽  
Who Guidelines ◽  
Global Database ◽  
Pool Water ◽  
Swimming Pool Water ◽  
By Products

Abstract This paper investigates disinfection by-products (DBPs) formation and their relationship with governing factors in chlorinated swimming pools. The study compares concentrations of DBPs with WHO guidelines for drinking water quality recommended to screen swimming pool water quality. The statistical analysis is based on a global database of 188 swimming pools accumulated from 42 peer-reviewed journal publications from 16 countries. The mean and standard deviation of dichloroacetic acid and trichloroacetic acid were estimated as 282 ± 437 and 326 ± 517 μg L−1, respectively, which most often surpassed the WHO guidelines. Similarly, more than half of the examined pools had higher values of chloral hydrate (102 ± 128 μg L−1). The concentration of total chloramines (650 ± 490 μg L−1) was well above the WHO guidelines in all reported cases. Nevertheless, the reported values remained below the guidelines for most of the studied pools in the case of total trihalomethanes (134 ± 160 μg L−1), dichloroacetonitrile (12 ± 12 μg L−1) and dibromoacetonitrile (8 ± 11 μg L−1). Total organic carbon, free residual chlorine, temperature, pH, total nitrogen and bromide ions play a pivotal role in DBPs formation processes. Therefore, proper management of these governing factors could significantly reduce DBPs formation, thereby, contributing towards a healthy swimming pool environment.

scholarly journals Comparison of trihalomethanes in the air of two indoor swimming pool facilities using different type of chlorination and different types of water

2017 ◽  
Vol 18 (4) ◽  
pp. 1350-1356 ◽  
Author(s):  
Therese B. Nitter ◽  
Wolfgang Kampel ◽  
Kristin v. H. Svendsen ◽  
Bjørn Aas
Keyword(s):  
Water Surface ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Breathing Zone ◽  
Calcium Hypochlorite ◽  
Air Samples ◽  
Future Studies ◽  
Indoor Swimming Pool ◽  
Different Types ◽  
By Products

Abstract Certain aspects of the distribution of disinfection by-products (DBPs) in the air of indoor swimming pools, the exposure of the users, and possible health effects, have not been well documented. To determine the distribution of trihalomethanes (THMs), measurements were performed at 0.05 m, 0.60 m and 1.50 m above the water surface. These heights were chosen to measure the exposure in the breathing zone of the users. Air samples were collected from two indoor swimming pool facilities in Norway. Facility 1 uses calcium hypochlorite and facility 2 uses sodium hypochlorite for water treatment. In facility 2, one of the swimming pools is filled with 33% seawater, while the other pools in this study were filled with freshwater. Higher values were measured at 0.05 m compared to 1.50 m. Negligible differences between the measurements at 0.60 m and 1.50 m above floor levels were obtained. On average, 282% higher concentrations of total THM (tTHM) were measured in facility 2. Different disinfection products and ventilation concepts are possible explanations. Swimmers are exposed to higher concentrations compared to users by the poolside. For future studies, it is crucial to measure as close to the water surface as possible.

scholarly journals Compliance of bathers to showering before swimming in a public pool in Toronto, Ontario

2021 ◽  
Vol 63 (4) ◽  
pp. 107-113
Author(s):  
Oluyemisi Omisakin ◽  
Ian Young
Keyword(s):  
Organic Material ◽  
Cross Sectional Study ◽  
Swimming Pool ◽  
Recreational Water ◽  
Swimming Pools ◽  
Sectional Study ◽  
Cross Sectional ◽  
Fecal Matter ◽  
By Products ◽  
Person Questionnaire

Bathers at public swimming pools should shower prior to entering the pool deck to remove organic material (e.g., sweat, lotions, fecal matter) that can increase the risk of recreational water illness and the formation of disinfection by-products. However, little research has been conducted to evaluate bathers’ pre-swimming showering practices. We conducted a cross-sectional study of bathers aged 18 years or older at a public swimming pool in Toronto, Ontario, to evaluate their showering habits. An in-person questionnaire was administered in October and November 2019. Bivariate associations were examined between selected variables and participants’ self-reported showering frequency prior to swimming (often or always vs. never, rarely, or sometimes). A total of 110 bathers agreed to participate. Most participants (63%) were aged 18–34, 56% identified as male, and 78.2% reported always or often showering before swimming. Of these individuals, only 34% reported using soap when showering. Participants that identified as male (vs. female) and an ethnicity other than white were more likely to report often or always showering, as were those that reported reading the pool rules and that observed other bathers taking a shower. Additional efforts are needed to educate bathers about the importance of showering prior to swimming in public pools.

scholarly journals Disinfection by-products monitoring in water of selected outdoor swimming pools in Opole Voivodship

2018 ◽  
Vol 59 ◽  
pp. 00027
Author(s):  
Iwona Klosok-Bazan ◽  
Marta Bożym ◽  
Małgorzata Wzorek
Keyword(s):  
Swimming Pool ◽  
Swimming Pools ◽  
Wide Range ◽  
By Products

The aim of this study was to determine the level of disinfection by-products in selected outdoor swimming pool in the Opole Voivodship. The authors paid special attention to the determination of the concentration of trihalomethanes (THMs), which are formed during disinfection in water. Five outdoor swimming pools were selected in five different cities located in Opole Region. The level of trihalomethane (THM) concentrations in the analyzed waters was found to be in the wide range from 15 to more than 550 µg/L. The dominant compound of THMs was chloroform because of chlorine application in the disinfection method.

scholarly journals Evaluating if airborne chemical levels in indoor swimming pools are influenced by type of water treatment

2020 ◽  
Vol 63 (2) ◽  
pp. 48-53
Author(s):  
Khayati Patel ◽  
Chun-Yip Hon
Keyword(s):  
Water Treatment ◽  
Ultra Violet ◽  
Sampling Period ◽  
Swimming Pool ◽  
Chemical Concentration ◽  
Swimming Pools ◽  
Indoor Space ◽  
Pool Water ◽  
Airborne Concentration ◽  
Significant Difference

Introduction Airborne chemical contaminants within an indoor space have the potential to cause adverse effects on those who work or visit the building. Indoor pools are no exception and airborne contaminants arise when chemicals, used for disinfection purposes, react with the pool water. Pool water can be treated by different means (e.g., chlorination or ultra-violet (UV) radiation) and whether the type of water treatment affects the airborne chemical levels is unclear. This study examined UV-treated vs. chlorine-treated swimming pools to determine if there is a difference in the resulting airborne chemical concentration of chlorine, hydrochloric acid (HCl) and trichloramines. Methods Two swimming pools (one UV-treated and one chlorine-treated) were selected to participate based upon the inclusion criteria. Partial period sampling was conducted on 3 different days at each facility when swim classes were occurring. For each sampling period, two ambient samples for each analyte (chlorine, HCl, and trichloramines) were collected according to recognized occupational hygiene protocols. Additionally, the temperature and relative humidity were measured, and other pool chemistry information was obtained. Comparative analyses were performed to ascertain if there was a difference in airborne chemical levels between the two pools. Results Summary statistics indicated very similar averages for each of the three airborne chemicals between the two water treatment types. A two-sample t-test found that the difference in means was not statistically significant for any of the three analytes. Conclusion There was no statistically significant difference reported in the mean airborne concentration for any of the analytes between the chlorine-treated swimming pool and the UV-treated swimming pool. In addition, all airborne chemical concentration levels were below their respective occupational exposure limit or recommended guideline level. The type of water treatment does not appear to impact the airborne chemical levels though further research is suggested to confirm these results.

scholarly journals Utility of the optical quality analysis system for decision-making in Nd: YAG laser posterior capsulotomy in patients with light posterior capsule opacity

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bo Lu ◽  
Weijie Zhu ◽  
Yu Fan ◽  
Dong Shi ◽  
Liwei Ma
Keyword(s):  
Area Under The Curve ◽  
Quality Parameters ◽  
Optical Quality ◽  
Quality Analysis ◽  
Posterior Capsule ◽  
Clinical Trial Registry ◽  
Posterior Capsulotomy ◽  
Significant Difference ◽  
Analysis System ◽  
Scattering Index

Abstract Background A prospective cohort study was performed to evaluate whether the Optical Quality Analysis System (OQAS) can serve as a valuable additional indicator for appropriate posterior capsulotomy referral. Methods One hundred and five eyes from 96 patients undergoing capsulotomy were divided into precapsulotomy logMAR CDVA ≤0.1 group and logMAR CDVA > 0.1 group. CDVA, and the Visual Function 14 index (VF-14) score were estimated before and 1 month after capsulotomy. The objective scattering index (OSI) value was measured by using the OQAS. Posterior capsule opacification (PCO) severity was assessed with Evaluation of PCO 2000 (EPCO 2000) software. Results In logMAR CDVA > 0.1 group, the correlations of OSI, logMAR CDVA, EPCO score and VF-14 score were very strong preoperatively. In logMAR CDVA ≤0.1 group, preoperatively, OSI was correlated with logMAR CDVA (r = 0.451), EPCO score (r = 0.789), and VF-14 score (r = 0.852). LogMAR CDVA has weak correlation with VF-14 score (r = − 0.384) and EPCO score (r = 0.566). VF-14 score was correlated with EPCO score (r = − 0.669). In the logMAR CDVA ≤0.1 group, there was no significant difference in logMAR CDVA between precapsulotomy and postcapsulotomy (P > 0.05). In the two groups, all the other optical quality parameters were significantly improved after capsulotomy (P < 0.05). In logMAR CDVA > 0.1 group, the area under the curve of the ROC of the OSI was 0.996 (P = 0.000). In logMAR CDVA ≤0.1 group, the area under the curve of the ROC of the OSI was 0.943 (P = 0.000). Conclusions The OSI was useful for evaluating of PCO and prediction of beneficial capsulotomy. Especially for patients with slight PCO and better visual acuity, OSI is more valuable than CDVA and completely objective examination. Trial registration The study protocol was registered at the Chinese Clinical Trial Registry. Register: ChiCTR1800018842 (Registered Date: October 13th, 2018).

Effect of surface sealant on surface roughness and bacterial adhesion of bulk-fill composites

2021 ◽  
pp. 096739112110055
Author(s):  
Gunce Ozan ◽  
Meltem Mert Eren ◽  
Cansu Vatansever ◽  
Ugur Erdemir
Keyword(s):  
Surface Roughness ◽  
Bacterial Adhesion ◽  
Confocal Laser ◽  
High Caries Risk ◽  
Two Samples ◽  
Significant Difference ◽  
Restorative Materials ◽  
Surface Sealants ◽  
Surface Sealant ◽  
Effect Of Surface

Surface sealants are reported to ensure surface smoothness and improve the surface quality of composite restorations. These sealants should also reduce the bacterial adhesion on composite surfaces however, there is not much information regarding their performance on bulk-fill composite materials. The aim of this study was to evaluate the effect of surface sealant application on surface roughness and bacterial adhesion of various restorative materials. Disc-shaped samples were prepared from a compomer, a conventional composite and three bulk-fill composites. Specimens of each group were divided into two groups (n = 9): with/without surface sealant (Biscover LV, [BLV]). Surface roughness values were examined by profilometry and two samples of each group were examined for bacterial adhesion on a confocal laser scanning microscope (CLSM). Bacterial counts were calculated by both broth cultivation and microscopic images. Results were analyzed with one-way ANOVA and Bonferroni/Dunn tests. Following the BLV application, there was a decrease in the surface roughness values of all groups however, only Tetric N-Ceram Bulk and Beautifil-Bulk groups showed significantly smoother surfaces (p < 0.001). There were no significant differences among material groups without BLV application. Evaluating bacterial adhesion after BLV application, conventional composite had the lowest values among all followed by the compomer group. Beautifil-Bulk had significantly the highest bacterial adhesion (p < 0.05), followed by Tetric N-Ceram Bulk group. Without BLV application, there was no significant difference among bacterial adhesion values of groups (p > 0.05). CLSM images showed cell viability in groups. Bulk-fill composites showed higher bacterial adhesion than conventional composite and compomer materials. The surface sealant was found to be highly effective in lowering bacterial adhesion, but not so superior in smoothing the surfaces of restorative materials. So, surface sealants could be used on the restorations of patients with high caries risk.

New retting method of cassava roots improve sensory attributes of Bobolo and Chikwangue in Central Africa: an approach through just about right (JAR) test

2021 ◽  
pp. 475
Author(s):  
Nardis NKOUDOU ZE ◽  
Marie-Joseph MEDZEME ENGAMA ◽  
Jean Justin ESSIA NGANG
Keyword(s):  
Sensory Analysis ◽  
Central Africa ◽  
Pasting Properties ◽  
Sensory Attributes ◽  
Sensory Characteristics ◽  
Sensory Profile ◽  
Jar Test ◽  
Two Samples ◽  
By Products ◽  
Penalty Analysis

Aim: the aim of this study was to determine sensory profile, through the use of just-about-right (JAR) scales and penalty analysis, of Bobolo and Chikwangue from the cassava roots fermented with previously cassava-fermented chips powder (PCFCP). Furthermore, retting time, cyanide content and pasting properties of retted roots were evaluated. Methods: for that, two samples of Bobolo and Chikwangue obtained from two cassava retting methods were studied: a control made from the retting without PCFCP and a product made from retting with PCFCP. Results: retting time was carried out in 48 hours less with PCFCP and 60% of cyanide reduction more than control. No major modifications occurs in pasting properties of paste fermented with PCFCP. The sensory analysis indicated high levels of acceptability for products made from retting with PCFCP. The penalty analysis showed that attributes “too sour” and “too much fermented odor” affected the acceptability of the Bobolo from retting without PCFCP significantly. Conclusion: fermentation of cassava through the use of PCFCP is suitable to improvement of sensory characteristics of fermented cassava by-products.

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