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Ahmadpour E, Debia M. Estimating airborne trichloramine levels in indoor swimming pools using the well-mixed box model. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2024:1-12. [PMID: 38669683 DOI: 10.1080/15459624.2024.2327370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
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.
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Affiliation(s)
- Elham Ahmadpour
- Department of Environmental and Occupational Health, School of Public Health, Le Centre de recherche en santé publique (CreSP), Université de Montréal, Montreal, Canada
| | - Maximilien Debia
- Department of Environmental and Occupational Health, School of Public Health, Le Centre de recherche en santé publique (CreSP), Université de Montréal, Montreal, Canada
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Ahmadpour E, Delpla I, Debia M, Simard S, Proulx F, Sérodes JB, Valois I, Tardif R, Haddad S, Rodriguez M. Full-scale multisampling and empirical modeling of DBPs in water and air of indoor pools. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1128. [PMID: 37650940 DOI: 10.1007/s10661-023-11619-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 07/19/2023] [Indexed: 09/01/2023]
Abstract
Disinfection by-products (DBPs) are formed in the water in swimming pools due to reactions between disinfectants (chlorine, bromine, ozone) and the organic matter introduced by bathers and supply water. High concentrations of DBPs are also reported in the air of indoor swimming pools. Based on a robust multisampling program, the levels and variations of DBPs in the air (trichloramine [TCAM] and trihalomethanes [THMs]) and water (THM) were assessed, as well as their precursors (total organic carbon, water temperature, pH, free, and total chlorine) and proxies (CO2 and relative humidity) in four indoor chlorinated swimming pools. High-frequency sampling was conducted during one high-attendance day for each pool. This study focused on parameters that are easy to measure in order to develop models for predicting levels of THMs and TCAM in the air. The results showed that the number of bathers had an important impact on the levels of THMs and TCAM, with a two-to-three-fold increase in air chloroform (up to 110 μg/m3) and a two-to-four-fold increase in TCAM (up to 0.52 mg/m3) shortly after pools opened. The results of this study for the first time showed that CO2 and relative humidity can serve as proxies for monitoring variations in airborne THMs and TCAM. Our results highlight the good predictive capacity of the developed models and their potential for use in day-to-day monitoring. This could help optimize and control DBPs formation in the air of indoor swimming pools and reduce contaminant exposure for both pool employees and users.
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Affiliation(s)
- Elham Ahmadpour
- Department of Occupational & Environmental Health, School of Public Health, Universite de Montreal, 2900, Boulevard Edouard-Montpetit, Montreal, QC, H3T 1J4, Canada
| | - Ianis Delpla
- Ecole superieure d'amenagement du territoire et de developpement regional (ESAD), Université Laval, Pavillon F-A. Savard, 2325, rue des Bibliothèques, local 1612, Quebec, QC, G1V 0A6, Canada.
| | - Maximilien Debia
- Department of Occupational & Environmental Health, School of Public Health, Universite de Montreal, 2900, Boulevard Edouard-Montpetit, Montreal, QC, H3T 1J4, Canada
| | - Sabrina Simard
- Ecole superieure d'amenagement du territoire et de developpement regional (ESAD), Université Laval, Pavillon F-A. Savard, 2325, rue des Bibliothèques, local 1612, Quebec, QC, G1V 0A6, Canada
| | - François Proulx
- Ecole superieure d'amenagement du territoire et de developpement regional (ESAD), Université Laval, Pavillon F-A. Savard, 2325, rue des Bibliothèques, local 1612, Quebec, QC, G1V 0A6, Canada
| | - Jean-Baptiste Sérodes
- Ecole superieure d'amenagement du territoire et de developpement regional (ESAD), Université Laval, Pavillon F-A. Savard, 2325, rue des Bibliothèques, local 1612, Quebec, QC, G1V 0A6, Canada
| | - Isabelle Valois
- Department of Occupational & Environmental Health, School of Public Health, Universite de Montreal, 2900, Boulevard Edouard-Montpetit, Montreal, QC, H3T 1J4, Canada
| | - Robert Tardif
- Department of Occupational & Environmental Health, School of Public Health, Universite de Montreal, 2900, Boulevard Edouard-Montpetit, Montreal, QC, H3T 1J4, Canada
| | - Sami Haddad
- Department of Occupational & Environmental Health, School of Public Health, Universite de Montreal, 2900, Boulevard Edouard-Montpetit, Montreal, QC, H3T 1J4, Canada
| | - Manuel Rodriguez
- Ecole superieure d'amenagement du territoire et de developpement regional (ESAD), Université Laval, Pavillon F-A. Savard, 2325, rue des Bibliothèques, local 1612, Quebec, QC, G1V 0A6, Canada
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Peng F, Lu Y, Dong X, Wang Y, Li H, Yang Z. Advances and research needs for disinfection byproducts control strategies in swimming pools. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131533. [PMID: 37146331 DOI: 10.1016/j.jhazmat.2023.131533] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/16/2023] [Accepted: 04/27/2023] [Indexed: 05/07/2023]
Abstract
The control of disinfection byproducts (DBPs) in swimming pools is of great significance due to the non-negligible toxicity and widespread existence of DBPs. However, the management of DBPs remains challenging as the removal and regulation of DBPs is a multifactorial phenomenon in pools. This study summarized recent studies on the removal and regulation of DBPs, and further proposed some research needs. Specifically, the removal of DBPs was divided into the direct removal of the generated DBPs and the indirect removal by inhibiting DBP formation. Inhibiting DBP formation seems to be the more effective and economically practical strategy, which can be achieved mainly by reducing precursors, improving disinfection technology, and optimizing water quality parameters. Alternative disinfection technologies to chlorine disinfection have attracted increasing attention, while their applicability in pools requires further investigation. The regulation of DBPs was discussed in terms of improving the standards on DBPs and their preccursors. The development of online monitoring technology for DBPs is essential for implementing the standard. Overall, this study makes a significant contribution to the control of DBPs in pool water by updating the latest research advances and providing detailed perspectives.
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Affiliation(s)
- Fangyuan Peng
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, PR China
| | - Yi Lu
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, PR China
| | - Xuelian Dong
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, PR China
| | - Yingyang Wang
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, PR China
| | - Haipu Li
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, PR China.
| | - Zhaoguang Yang
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, PR China.
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Ahmadpour E, Hallé S, Valois I, Ryan PE, Haddad S, Rodriguez M, Tardif R, Debia M. Comparison of sampling collection strategies for assessing airborne trichloramine levels in indoor swimming pools. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:36012-36022. [PMID: 36539665 DOI: 10.1007/s11356-022-24790-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
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.
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Affiliation(s)
- Elham Ahmadpour
- Department of Environmental and Occupational Health, School of Public Health, Centre de recherche en santé publique (CReSP), Université de Montréal, Montreal, Canada
| | - Stéphane Hallé
- Department of Mechanical Engineering, École de Technologie Supérieure (ETS), Montreal, Canada
| | - Isabelle Valois
- Department of Environmental and Occupational Health, School of Public Health, Centre de recherche en santé publique (CReSP), Université de Montréal, Montreal, Canada
| | - Patrick Eddy Ryan
- Department of Environmental and Occupational Health, School of Public Health, Centre de recherche en santé publique (CReSP), Université de Montréal, Montreal, Canada
| | - Sami Haddad
- Department of Environmental and Occupational Health, School of Public Health, Centre de recherche en santé publique (CReSP), Université de Montréal, Montreal, Canada
| | - Manuel Rodriguez
- École Supérieure d'aménagement du Territoire Et de Développement Régional (ESAD), Université Laval, Québec, Canada
| | - Robert Tardif
- Department of Environmental and Occupational Health, School of Public Health, Centre de recherche en santé publique (CReSP), Université de Montréal, Montreal, Canada
| | - Maximilien Debia
- Department of Environmental and Occupational Health, School of Public Health, Centre de recherche en santé publique (CReSP), Université de Montréal, Montreal, Canada.
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