HClO is the active ingredient of chlorination disinfectants, removing a variety of parasites, bacteria and viruses. However, although attacking microbes and viruses, HClO also reacts with many pool water substances and produces various DBPs. DBPs can be inhaled and ingested during swimming or absorbed dermally, and two classes of DBPs, chloroform and chloramines, have been the focus of most swimming pool studies thus far [ 26 ].
To better understand the corresponding metabolic stress pathways, the metabolism of these two classes of DBPs is illustrated in Fig. CHCl 3 is primarily metabolized oxidatively to trichloromethanol and spontaneously decomposed to the electrophilic phosgene COCl 2.
COCl 2 is highly reactive, and binds covalently to cell components containing nucleophilic groups, and may be hydrolyzed by reacting with water, yielding CO 2 and HCl. Chloroform is primarily metabolized in the liver, which explains its hepatoxicity; however, chloroform metabolism also occurs in other tissues, such as the kidneys. Chloroform metabolism may occur via two pathways, oxidative and reductive, but primarily via the oxidative pathway Fig.
Extensive rodent studies have demonstrated that chloroform may be metabolized oxidatively to trichloromethanol and spontaneously decomposed to the electrophilic phosgene COCl 2 [ 28 — 29 ]. COCl 2 is highly reactive, and binds covalently to cell components containing nucleophilic groups, including proteins, reduced glutathione, and phospholipid polar heads [ 30 — 31 ], and may be hydrolyzed by reacting with water, yielding carbon dioxide and hydrochloric acid HCl.
These compounds are all highly toxic to cells. These compounds can attack cells directly or indirectly by reacting with amino acids, destroying membranes, changing the construction and function of proteins and lipids, unbalancing the acid-base balance, blocking metabolism and by inducing respiratory burst. To eliminate the health hazards of these 4 compounds, the corresponding metabolic stress reactions occur in organisms.
As shown in Table 1 , taurine is the No. As shown in Fig. Second, by increasing the activities of intracellular GSH, taurine also plays an important role in eliminating COCl 2.
Additionally, because taurine reacts directly with HClO and indirectly with other oxidative radicals, the urinary excretion of the EG rats showed a declining trend. As above-mentioned, NH 3 and HCl are also highly toxic to cells. In these procedures, hippurate and citrate play important roles. Thus, the TCA and oxidative phosphorylation are inhibited [ 25 ]. To meet the increased demand of energy for recovery from the fatigue caused by swimming training and by stress reactions against the toxic compounds, the skeletal muscle must catalyze more phosphocreatine and creatine, thus resulting in elevated urine creatinine.
Meanwhile, the inhibited TCA and the inhibited oxidative phosphorylation also explain the inferior performance of the EG rats in the swimming capacity test.
In summary, the week swimming training in chlorinated pool water did induce some disease symptoms, an impairment of training effects and a significant change in the metabolic profiles, although the growth and behaviors of the experimental animals were not affected. The bloody noses, bloody eyes, lackluster fur and hair removal reflected the direct irritation of the DBPs to the respiratory tract, eyes and skin because these organs were in direct contacted with the DBPs.
However, possibly because of the protection from nasal mucous, the respiratory tract showed some adaptability to the DBPs. Thus, the eyes and skin might be the organs that require greater attention for permanent damage. Symptoms found in the liver and lung sections indicate that the liver is most likely the most possible target organ of DBPs, and training intensity, training frequency and water choking may be the primary factors for lung damage induced by swimming, instead of chlorination.
The result of the swimming capacity test showed that training effects were significant affected by chlorinated water through perturbing the TCA cycle and oxidative phosphorylation. Through analyzing the changes in metabolic profiles using a multivariate analysis, corresponding metabolic stress pathways were proposed, as shown in Fig.
Based on these pathways, the underlying toxicological mechanisms of DBPs are illustrated, and corresponding countermeasures can be developed. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. National Center for Biotechnology Information , U. PLoS One. Published online Mar 5.
Hans-Joachim Lehmler, Academic Editor. Author information Article notes Copyright and License information Disclaimer. Competing Interests: The authors have declared that no competing interests exist. Received May 7; Accepted Jan This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
Abstract Chlorination is the most popular method for disinfecting swimming pool water; however, although pathogens are being killed, many toxic compounds, called disinfection by-products DBPs , are formed. Introduction Chlorination is the most popular method for disinfecting swimming pool water. Materials and Methods Animals Animal welfare and experimental procedures were performed in accordance with the Guide for the Care and Use of Laboratory Animals Ministry of Science and Technology of China, and were approved by the animal ethics committee of Jiangxi Normal University.
Chlorination DBP measurements Two typical classes of chlorination DBPs, chloroform and chloramines, were measured at the 20th minute of every training session. Behaviors and appearances Behaviors and appearances of the rats were observed throughout the study. Swimming capacity test After the week swimming training and one day of rest, a swimming capacity test was performed. Results and Discussion Concentrations of the typical chlorination DBPs Concentrations of the two typical classes of chlorination DBPs chloroform and chloramines , which were measured at the 20 th minute of the swimming training, were 0.
Behaviors and Appearances The final body weights of the rats measured before euthanasia were extremely close between the EG and the CG Swimming capacity test The duration period from the entry into water until the rats reached exhaustion was significantly shorter for the EG rats compared with the CG rats Histopathological analysis The results of histopathological analysis is shown in Table 1.
Table 1 The results of histopathological analysis. Open in a separate window. Fig 1. Fig 2. Fig 3. Score plot left and loading plot right of the principal component analysis. Peak assignment and changing trends of the assigned metabolites The peaks with large loadings in the first three PCs Fig. Fig 4. Assignment and intensity comparison of peaks with large loadings. Table 2 Metabolites with large loadings and their changing trends in the experimental group.
Meanings of PC 1 As shown in Table 2 , the first representative metabolite of PC 1 is taurine, followed by citrate and by creatinine. Meanings of PC 3 Apart from taurine, which was discussed above, the second representative metabolites of PC 3 is hippurate Table 1.
Meanings of PC 2 As shown in Table 2 , the first representative metabolite of PC 2 is citrate, followed by taurine and hippurate, which indicates that the elevated urine excretion of citrate might be related to the changes in taurine and hippurate. Metabolism of chlorination DBPs Chlorine is a necessary element for our bodies, and nontoxic. Fig 5. Metabolism of the representative chlorination disinfection by-products DBPs in swimming pools.
Corresponding metabolic stress pathways To eliminate the health hazards of these 4 compounds, the corresponding metabolic stress reactions occur in organisms. Fig 6. Corresponding metabolic stress pathways to the chlorination disinfection by-products DBPs. Conclusions In summary, the week swimming training in chlorinated pool water did induce some disease symptoms, an impairment of training effects and a significant change in the metabolic profiles, although the growth and behaviors of the experimental animals were not affected.
PDF Click here for additional data file. XLS Click here for additional data file. Data Availability All relevant data are within the paper and its Supporting Information files. References 1. Respiratory risks associated with chlorinated swimming pools: a complex pattern of exposure and effects. Airway remodeling and inflammation in competitive swimmers training in indoor chlorinated swimming pools.
J Allergy Clin Immunol. Health effects of disinfection by-products in chlorinated swimming pools. Int J Hyg Environ Health. Lubick N. Swimming in chlorine byproducts. Environ Sci Technol. Disinfection byproducts and bladder cancer.
Apooled analysis. Lung hyperpermeability and asthma prevalence in schoolchildren: unexpected associations with the attendance at indoor chlorinated swimming pools. Occup Environ Med. Respiratory symptoms include coughing , difficulty breathing , and fluid inside the lungs. In some cases, children may consume cleaning products that contain chlorine.
Take children who show signs of chlorine poisoning to a hospital or emergency room immediately. Seek medical assistance immediately if you or your child comes into contact with chlorine.
If you get chlorine on your skin, immediately wash it with soap and water. If you get it in your eyes, flush them with running water for at least 15 minutes — take out contact lenses first if present. Remove any clothes that were on the areas of the body exposed to chlorine. If you accidentally swallow chlorine, drink milk or water immediately, unless you experience vomiting or convulsions. If you inhale chlorine, seek fresh air as soon as possible. Going to the highest possible ground to seek fresh air is helpful because chlorine is heavier than air.
Medical professionals will want to know the following information to treat your chlorine poisoning more effectively:. This includes your pulse, temperature, blood pressure, oxygenation, and breathing rate. Doctors may also give you one or more of the following to help ease symptoms and help your body deal with the chlorine:. You might require placement of a breathing tube into your airway for mechanical ventilation if you have trouble breathing.
Doctors might use a special tool to view your throat and determine if you have serious burns in your airways or lungs.
A nasogastric tube may need to be inserted into your stomach to empty its contents. Medical staff may need to wash affected skin at hourly intervals. Chlorine poisoning can have serious effects on the body. The outlook for recovery depends on the amount of chlorine touched, swallowed, or inhaled and how quickly treatment is obtained. You have a better chance for full recovery if you receive medical help promptly.
Follow proper methods for handling chlorine. An overchlorinated pool, on the other hand, can cause eye irritation , dry out the hair and skin by stripping them of natural oils , and sometimes cause color-treated hair to turn shades of green, Duarte told Live Science.
Because of this, it's important to have the right levels of chlorine in the pool, she said. Excess chlorine in the pool can sometimes also cause small amounts of vapor to come out of the water, which "can trigger [a person's] asthma," Duarte said, though she noted that she doesn't think this effect is too common.
But as overeager swimmers may recall, pools are typically closed right after pool keepers chlorinate the water so that some of those vapors can diffuse, she said. In high concentrations, chlorine gas is known to be very poisonous. In World War I, for example, chlorine gas was used as a chemical weapon. Inhaling large amounts of the gas is poisonous and could cause what's called a pulmonary edema, or fluid buildup in the lungs, according to the New York State Department of Health.
In general, swimmers need not worry about chlorine. Even if you don't rinse off, the consequences won't be dire, she said: You may end up with a bit of dry skin, or brittleness in your hair.
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