Pilot Test on Pre-Swim Hygiene as a Factor Limiting Trihalomethane Precursors in Pool Water by Reducing Organic Matter in an Operational Facility

Abstract

Pool water must be constantly disinfected. Chlorine compounds used to disinfect pools react with organic substances such as sweat, urine, and personal care products introduced into pool water by users and results in the formation of disinfection byproducts. Trihalomethanes (THM), including chloroform and dissolved organic carbon (DOC) concentrations, were quantified using a two-stage process: determining initial THM and chloroform levels; then searching for a cheap and easy-to-use method to improve water quality. The method proposed here to limit THM and DOC concentrations in water is controlled showering. At three swimming pool facilities, chloroform concentrations (13.8 ± 0.33 µg/L, 15.5 ± 0.44 µg/L, and 13.9 ± 0.06 µg/L) were below the threshold concentration of 30 μg/L. At a fourth facility, however, the chloroform concentration exceeded that threshold (40.7 ± 9.68 μg/L) when showering was not controlled. Those conditions improved after the introduction of a mandatory shower; concentrations of DOC, THMs, and chloroform all decreased. The chloroform concentration decreased to 29.4 ± 3.8 μg/L, the THM concentration was 31.3 ± 3.9 μg/L, and the DOC concentration was 6.09 ± 0.05 mg/L. Pilot tests were carried out at real facilities to determine whether the control of pre-swim hygiene was possible. The introduction of proper pre-swim hygiene limited the concentration of DOC in water and can lead to a healthier environment for everyone attending the swimming facility.

Public Attitudes to Visiting Swimming Pools and Water Parks

“…Однак, відомо, що запах, який помилково сприймається відвідувачами, як запах хлору, навпаки свідчить про забруднення води органічними речовинами, що реагують з хлором та формують хлорорганічні сполуки (наприклад, хлораміни). Моно-, ди-та трихлораміни є винними не лише в тому, що плавці відчувають специфічний «запах хлору», а й в тому, що можуть викликати подразнення та почервоніння очей (Bai & Blatchley, 2016;Kaczmarek et al, 2020;Ratajczak & Pobudkowska, 2020). Крім того, високий рівень трихлорамінів викликає зміну показника pH води та концентрацію вільного хлору, що зменшує його бактерицидну активність.…”

“…Потенціал утворення побічних продуктів хлорування залежить як від кількості хлору, що використовується для дезінфекції, так і від кількості органічних речовин, які вносять до ванни басейну відвідувачі (Dyck & Tardif, 2011). Так, проведене в 2020 році дослідження важливості прийняття душу до і після басейну, та після кожного відвідування туалету показало, що ці заходи мають істотний вплив на рівень хлорорганічних сполук, наприклад, хлорамінів (Ratajczak et al, 2020). Дослідження проведене в Італії, показало слабке усвідомлення плавцями профілактичної ролі прийому душу при відвідуванні басейну та необхідність посилення освітніх заходів, щодо інформування відвідувачів про причини важливості прийому душу перед кожним заходом до басейну (Pasquarella et al, 2013).…”

Revisiting the Gage–Bidwell Law of Dilution in Relation to the Effectiveness of Swimming Pool Filtration and the Risk to Swimming Pool Users from Cryptosporidium

“…The progress of turbidity (NTU) was modelled on an hourly basis using Equation ( 14) to predict the transitions in turbidity each hour. C o was the turbidity value (NTU) at the end of the preceding hour, and C e was calculated using Equation (12), based on the number of bathers entering the pool that hour and an assumed value for the turbidity input per bather. With a water-turnover time of 1.06 h and a filter efficiency of 0.9, Equation (14) predicts that in 1 h there will be 57% of the transition from C 0 to C e .…”

“…It is seen that the observed peak turbidity fell short of the equilibrium turbidity values, which is also indicated by the absence of any evident plateauing of turbidity (NTU) values during the busiest periods (Figure 4). However, because in this example the water-turnover time was The solid line in Figure 5 shows the equilibrium turbidity values that were predicted using Equation (12), corresponding to the peak mid-afternoon bathing loads. It is seen that the observed peak turbidity fell short of the equilibrium turbidity values, which is also indicated by the absence of any evident plateauing of turbidity (NTU) values during the busiest periods (Figure 4).…”

“…In addition to the cleaning up of a pool following a faecal contamination event, the other aspect of the performance of a pool filtration system that is of interest to designers, operators and those responsible for producing industry guidelines is the maximum concentration of contaminants, in particular turbidity, that is likely to result from the particles derived from anthropogenic sources (including dirt) washed off bathers in a pool [11]. This is likely to be dependent on the number and type of the bathers and pre-swim hygiene arrangements used in normal operation [12]. This was touched on in the 1926 abstract by reference to there being an equilibrium that exists between the input of dirt and the removal of dirt, according to the Gage-Bidwell Law of Dilution (though this theme was not developed further).…”