Academic literature on the topic 'Trichloramine'

In this study an in vitro exposure test to investigate toxicological effects of the volatile disinfection by-product trichloramine and of real indoor pool air was established. For this purpose a set-up to generate a well-defined, clean gas stream of trichloramine was combined with biotests. Human alveolar epithelial lung cells of the cell line A-549 were exposed in a CULTEX® device with trichloramine concentrations between 0.1 and 40 mg/m3 for 1 h. As toxicological endpoints the cell viability and the inflammatory response by the cytokines IL-6 and IL-8 were investigated. A decreasing cell viability could be observed with increasing trichloramine concentration. An increase of IL-8 release could be determined at trichloramine concentrations higher than 10 mg/m3 and an increase of IL-6 release at concentrations of 20 mg/m3. Investigations of indoor swimming pool air showed similar inflammatory effects to the lung cells although the air concentrations of trichloramine of 0.17 and 0.19 mg/m3 were much lower compared with the laboratory experiments with trichloramine as the only contaminant. Therefore it is assumed that a mixture of trichloramine and other disinfection by-products in the air of indoor pool settings contribute to that effect.

The main requirements of designing the internal microclimate in swimming pool halls include removing evaporating water vapor and trichloramine (NCL3) from occurrence area of swimmers. As it is apparent from the differential equation of the mass transfer over the water surface, so with increasing speed above the water level there is increasing evaporation of water vapor at the same time. This is undesirable in view of the requirement to maintaining humidity below the upper limit of recommended limits. The article aims to point out the problem with the releasing trichloramines from the water surface and thus point to a potential increase in water vapor evaporated from the water.

In order to identify the optimal pH range for chlorinated swimming pools, the formation of trihalomethanes, haloacetonitriles and trichloramine was investigated in the pH-range 6.5–7.5 in batch experiments. An artificial body fluid analogue was used to simulate bather load as the precursor for by-products. The chlorine-to-precursor ratio used in the batch experiments influenced the amounts of by-products formed, but regardless of the ratio the same trends in the effect of pH were observed. Trihalomethane formation was reduced by decreasing pH, but haloacetonitrile and trichloramine formation increased. To evaluate the significance of the increase and decrease of the investigated organic by-products at the different pH values, the genotoxicity was calculated based on literature values. The calculated genotoxicity was approximately at the same level in the pH range 6.8–7.5 and increased when pH was 6.7 or lower. An optimal pH range for by-products formation in swimming pools was identified at pH 7.0–7.2. In the wider pH range (pH 6.8–7.5), the effect on by-product formation was negligible. Swimming pools should never be maintained at lower pH than 6.8 since formation of both haloacetonitriles and trichloramine increase significantly below this value.

The work deals with solution of air distribution in swimming pool halls with regard to the dominant influences, which are creating a microclimate in these areas. Results of this work are graphs with evaporation of water and chemicals dependents on changing boundary con-ditions. There is followed with optimal design of air distribution, which is reflecting the critical specific effects of swimming pool halls.

Allmänna bad bidrar i hög grad till att främja allmänhetens hälsa och välbefinnande. De erbjuder möjlighet till motion och rekreation för människor i alla åldrar. För att badgäster ska trivas och må bra krävs det att vatten- och luftkvalitet håller hög nivå. I syfte att förhindra spridning av sjukdomsalstrande organismer mellan badgäster används klor som en central komponent för att desinficera vattnet. Kloret lämnar dock restprodukter efter sig, främst trikloramin som påverkar människors hälsa negativt. Trikloramin samlas över vattenytan och stannar kvar i andningszonen om inte föroreningarna transporteras bort via luftrörelser.  I Nolhaga simhall sker fram till 2018 en ombyggnad av anläggningen. Rapporten berör den nya ventilationslösning som kommer att användas till motionsbassängen. För att studera hur denna lösning fungerar och hur god luftväxling den skapar över vattenytan har en modell av simhallen skapats i CAD-program. Luftflöden har sedan simulerats i en förenklad CFD modellen och jämförts med ett röktest i en liknande simhall. Utöver den lösning som är tänkt att byggas har ett alternativ med kompletterande frånluftsdon i golvnivå simulerats.  Resultatet indikerar att lufthastigheter över vattenytan ligger inom de rekommendationer som finns angivna. Luften har en tendens att röra sig i lokalen med ett återcirkulerande beteende där tilluften följer taket in i hallen för att sedan gå ner vid bakre väggen och tillbaka över vattenytan. Luftrörelserna följer detta beteende oberoende om frånluftsdonet är placerat i golv- eller taknivå. Någon skillnad i mängd bortfört trikloramin kan inte säkerställas med de metoder som använts i rapporten. Röktestet gav inte ett tillräckligt tydligt resultat för att några kopplingar till simulering ska kunna göras. Brist på tid, förkunskaper och erfarenhet inom området gör att osäkerheten kring de resultat som nåtts är stor. Mer arbete inom CFD och badhusventilation krävs för att öka trovärdigheten.

碩士
國立臺灣大學
環境衛生研究所
100
Chlorination is an important treatment at swimming pools. With human-introduced compounds, various disinfection by-products (DBPs) might be formed. Among the DBPs, trichloramine appears as gaseous form in the atmosphere at indoor swimming pools. Levels of trichloramine, and its health concerns among simmers and lifeguards at indoor swimming pools have been studied in many countries previously. The purpose of this study was then to describe the scenario of trichloramine exposures at indoor swimming pools in Taiwan and to discover the factors affecting the levels of trichloramine. In this study, sampling and analysis method for airborne trichloramine was set up according to the methods published elsewhere. The trichloramine air sampler was composed with two components: the first one was 6mL cartridge tube filled with sulphamic acid coated silica gel, and the second one was 37mm sampling cassette with diarsenic trioxide and sodium carbonate coated quartz fiber filters. It was an active air sampling method, and the air flow rate was set at 1L/min. After sampling, the quartz fiber filter was desorbed by 10mL ultrapure water and further analyzed by ion chromatography. Questionnaires were administrated in this study and the information about swimming pool maintenance was also collected. Ten indoor swimming pools in Taipei were included for field sampling. Concentrations of trichloramine were found to be ranged from 0.017 to 0.15mg/m3 (total of 78 samples). For the pool workers who completed the questionnaire, 51 out of 104 were male, and 48 of them were lifeguards. Among the reported prevalence of respiratory symptoms at work, experiencing eye irritation and cough were the highest. Besides, symptom of sore throat and phlegm were more likely to happen among the high-exposed group (i.e., lifeguards and swimming instructors) than the low-exposed group (odds ratio ranged from 1.44~88.33 and 1.16~15.4 for sore throat and phlegm, respectively). On the other hand, the concentrations of free available chlorine (FAC) in pool water and the number of swimmers were significantly associated with the levels of airborne NCl3 (p-value= 0.003). It is suggested that the regulated FAC levels in different countries may cause the concentrations of trichloramine reported elsewhere to be nonidentical. To lower the level of trichloramine at indoor swimming pool, well-functioned filtration and ventilation systems as well as hygiene code for swimmers are necessary. Changing parts of pool water regularly is also an efficient way. The relatiohship between the FAC value and the airborne trichloramine level should be further concerned.

Dissertação de mestrado integrado em Engenharia Civil
A consciencialização, por parte da população em geral, acerca dos benefícios da prática de atividades físicas aquáticas deu aso a um aumento da afluência a este tipo de instalações, verificando-se, em consequência, um aumento das cargas poluentes. A desinfeção é um processo capaz de reduzir o risco da proliferação de doenças transmissíveis por via hídrica, no entanto, os subprodutos (SPD) gerados (da reação dos compostos clorados com a matéria orgânica natural), podem induzir ao aparecimento de substâncias potencialmente cancerígenas e/ou mutagénicas. Neste âmbito, o presente trabalho de investigação tem como objetivo contribuir para o desenvolvimento e otimização de metodologias para o controlo da qualidade da água de piscinas interiores públicas, de modo a mitigar os potenciais impactos negativos na saúde pública originados pela presença de SPD indesejáveis ou tóxicos. Assim, numa primeira fase procedeu-se à implementação de métodos já estabelecidos para síntese e quantificação de tricloraminas. Relativamente à produção, esta foi efetuada com a junção dos seus principais precursores, ureia e ácido hipocloroso. Como método de quantificação recorreu-se a três metodologias baseadas em leitura espetrofotométrica, das quais apenas uma permitiu resultados quantificáveis (norma AFNOR T90-037). Esta validação permite que em desenvolvimentos futuros se possam avaliar, com recurso a este método indireto (menos sofisticado), a eficiência de remoção de tricloraminas. Numa segunda fase, foi efetuada uma análise do risco carcinogénico e não carcinogénico associado à exposição a trihalometanos (THM) presentes na água distribuída nos 18 municípios do distrito do Porto e na água de piscinas do concelho. Para tal, o modelo de cálculo foi efetuado com base no método desenvolvido pela United States Environmental Protection Agency (USEPA) mas com parâmetros de entrada adequados às características da edificação e população portuguesa. Em ambos os casos as maiores concentrações de THM dão origem a riscos mais elevados, nomeadamente para as mulheres face à maior esperança média de vida e menor massa corporal. Todos os concelhos e piscinas apresentam um risco carcinogénico (CR) superior ao aceitável (CR<1E-06) e um risco não carcinogénico desprezável (HI<1). Relativamente ao risco carcinogénico, em águas de abastecimento a ingestão revelou-se a principal via de exposição, por outro lado, em piscinas, a inalação representa a principal fonte de risco. O risco máximo foi registado em Felgueiras (9,29E-05) e na piscina K (2,58E-04). Comparando o risco verificado em águas de abastecimento e em piscinas verificou-se que todas as piscinas possuem uma concentração de THM superior no período em análise e, consequentemente, um maior risco associado.
Awareness of the general population about the benefits of practicing aquatic physical activities has resulted in an increased affluence to this type of facilities. As a result, there is an increase in polluting loads due to body secretions and cosmetic residues. Disinfection, like the oxidation process of organic matter, reduces the risk of waterborne disease proliferation, however, the by-products (SPD) (generated from the reaction of the disinfectant with natural organic matter), may induce the appearance of potentially carcinogenic and/or mutagenic substances. In this context, the present research work has as main objective to contribute to the development of appropriate methodologies for the control of water quality in public indoor pools, in order to mitigate the potential negative impacts on public health caused by the presence of undesirable or toxic SPD. That been said, we began with the implementation of already established methods for synthesis and quantification of trichloramines. Regarding production, this was done with the combination of its main precursors, urea and hypochlorous acid. As a method of quantification, 3 methodologies based on spectrophotometric reading were used, of which only one obtained quantifiable results (standard AFNOR T90-037). In the second instance, an analysis of the carcinogenic and non-carcinogenic risk associated with exposure to trihalomethanes (THM) present in water distributed in the 18 municipalities of the district of Porto and in pools located in the same region was carried out. For that purpose, the calculation model was executed based on the method developed by the United States Environmental Protection Agency (USEPA) and adapted with input parameters appropriate to the characteristics of the Portuguese building and population. In both cases, the highest concentrations of THM give rise to higher risks, primarily in women due to higher average life expectancy and lower body mass. All municipalities and swimming pools have a higher than acceptable carcinogenic risk (CR>1E-06) and a negligible non-carcinogenic risk (HI<1). Regarding the carcinogenic risk, in water supply, ingestion proved to be the main route of exposure, whereas, in swimming pools, inhalation represents the main source of risk. The maximum risk was recorded in Felgueiras (9.29E-05) and in pool K (2.58E-04). Comparing the risk verified in water supply and in swimming pools, it was found that all swimming pools have a higher THM concentration in the period under analysis and, consequently, a higher associated risk.