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Showing Normal Urinary bladder, Normal epithelia (Arrow), H&E4x.
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The experiment was designed to investigate the histopathological changes in
rat’s tissues due to the effect of the trihalomethane (THM) - chloroform
when administered in drinking water. A group of male Wistar rat was
exposed to trihalomethane-chloroform (TCM) at concentration 750 ppm in
their drinking water and dose 16.17 mg/kg for a month. The...
Citations
... Chlorination cause mutation in bacterial DNA, however, its effect on mammalian cell has also been documented previously (de Castro Medeiros et al., 2019). A study reported that THMs (750 mg L À1 ) are responsible for hepatotoxicity, hyperplasia in urinary bladder and metaplasia in small intestine of male Wistar rats at dose 16.17 mg kg À1 and time duration of 1 month (Abd El-Halim et al., 2017). Another study suggested that THMs could be responsible for almost 700 cancer cases in Canada (Chowdhury et al., 2011). ...
Disinfection is considered as a vital step to ensure the supply of clean and safe drinking water. Various approaches are adopted for this purpose; however, chlorination is highly preferred all over the world. This method is opted owing to its several advantages. However, it leads to the formation of certain by-products. These chlorination disinfection by-products (DBPs) are genotoxic, carcinogenic and mutagenic. Still chlorination is being practiced worldwide. Present review gives insights into the occurrence, toxicity and factors affecting the formation of regulated (THMs, HAAs) and emerging DBPs (N-DBPs, HKs, HAs and aromatic DBPs) found in drinking water. Furthermore, remediation techniques used to control DBPs have also been summarized here. Key findings are: (i) concentration of regulated DBPs surpassed the permissible limit in most of the regions, (ii) high chlorine dose, high NOM, more reaction time (up to 3 hours) and high temperature (up to 30°C) enhance the formation of THMs and HAAs, (iii) high pH favors the formation of THMs while low pH is suitable of the formation of HAAs, (iv) high NOM, low temperature, low chlorine dose and moderate pH favors the formation of unstable DBPs (N-DBPs, HKs and HAs), (v) DBPs are toxic not only for humans but for aquatic fauna as well, (vi) membrane technologies, enhanced coagulation and AOPs remove NOM, (vii) adsorption, air stripping and other physical and chemical methods are post-formation approaches (viii) step-wise chlorination is assumed to be an efficient method to reduce DBPs formation without any treatment. Toxicity data revealed that N-DBPs are found to be more toxic than C-DBPs and aromatic DBPs than aliphatic DBPs. In majority of the studies, merely THMs and HAAs have been studied and USEPA has regulated just these two groups. Future studies should focus on emerging DBPs and provide information regarding their regulation.
... They can cause pancreas cancer, too. Also, the impact of THMs on the epithelial tissue of intestine is proven (52,73). So, both predicted mechanisms are involved in the process of exposure to THMs and pathology of intestine cancer. ...
... Also, many chemicals can cause liver problems; for example, exposure to aflatoxin is a major risk factor for the pathology of liver cancer (65). Multiple DBPs can cause liver cancer, including THMs such as bromodichloromethane (13,52), HAAs such as dichloroacetic acid and trichloroacetic acid (53,83), and many unregulated DBPs (13). Chloroacetaldehyde, bromochloroacetic acid, bromodichloroacetic acid, dibromochloroacetic acid, dibromoacetic acid, chloral hydrate, and MX, are among those DBPs with a proven effect on increasing the risk of developing liver cancer (13,(54)(55)(56)(57). Liver cancer due to exposure to chloroform and THMs is roughly related to cytotoxicity and cell multiplying in tissues (46). ...
Context: Cancer continues to be the first cause of mortality and morbidity all over the world, while the incidence of cancer is expected to increase by 50% over the next 20 years. Since the incidence of most of the cancers is increasing daily, it has been more
important to find related environmental risk factors. The epidemiological evidence indicates the effect of disinfection byproducts
(DBPs) through drinking water, as an environmental exposure, on most of the cancers. The goal of the current study was to combine
the results of most recent publications regarding the relationship between DBPs and their carcinogenic effects.
Evidence Acquisition: Using the main keywords of “cancer”, “drinking water”, and “disinfection byproducts”, a comprehensive
search was done among several research databases.
Results: Based on the previous studies, DBPs could cause most types of cancers, mainly including gastrointestinal, renal, bladder,
breast, liver, and thyroid cancers. Liver and renal cancers are the most common target organs for toxicity by DBPs. Among the
various DBPs, trihalomethanes are the most studied due to their relatively high prevalence and concentration in drinking water.
Also, haloacetic acids, such as trichloroacetic acid and dichloroacetic acid, have been known as one of the most affecting risk factors.
Unregulated DBPs, such as Mutagen X and Formaldehyde, are also of importance as they mostly have irreversible systemic effects.
Providing safe drinking water resources, restriction of unreasonable usage of disinfectants, and alternating disinfectants with less
harmful products could be the possible ways to overcome this crisis.
Conclusions: Disinfection byproducts can result in cancer development, especially in liver and kidneys. Providing safe drinking
water resources, using the membrane filters and changing the chlorination point are effective ways to encounter the risk of DBP
poisoning.
The term “disinfection” is defined as a process that kills only vegetative organisms or disinfection refers to killing or inactivation of microorganisms that can cause infection or a disinfectant is one of a diverse group of chemicals which reduces the number of microorganisms present in solution. In the process of disinfection usually involves chemicals, heat or UV light. To ensure microbiological quality, disinfection treatment is of primary importance. Healthcare workers experience high exposure to a wide range of cleaning and disinfecting products. In recent years, there is an increasing consensus that improved cleaning and disinfection of environmental surfaces is needed in healthcare facilities. Using disinfectants, pathogenic bacteria from the water can be killed and water made safe for the user. Disinfection of the water supply is an important and cost-effective tool to reduce morbidity and mortality from a wide range of infectious diseases. However, the chemicals used to treat water also can produce potentially toxic compounds known as disinfection by-products (DBPs). DBPs form when disinfectants (such as chlorine) react with organic matter that collects in water (such as algae or humic acids from decayed leaves). Most DBP exposure is due to ingestion of drinking water, although some DBPs can be inhaled or absorbed through the skin during bathing, showering, or swimming in a pool. Disinfection by-products (DBPs) form in swimming pool water from reactions between disinfectants such as chlorine and organic matter such as sweat, skin cells, and urine. Laboratory studies show that many DBPs are mutagenic or carcinogenic. Disinfection by-products (DBP) exposures have also been linked with digestive system cancers, but few studies have evaluated relationships with pancreatic cancer.
Chlorine is a widely used water disinfectant, while fluoride is an element which is naturally found in water or artificially added to it. Many regulations have been set to monitor the quality of water and ensure its safety. Chlorine and fluoride have many toxic effects if their levels exceeded the allowed levels. This work aimed estimation of levels of chlorine and fluoride in drinking water of Benha city and study their chronic toxic effects on adult male albino rats. Method: collecting water samples from urban areas, rural areas and bottled water then estimate levels of chlorine and fluoride. Seventy adult male albino rats were divided as follows: control group (10 rats), chlorine groups (30 rats which have been subdivided into three groups received different doses of chlorine for eight weeks). Fluoride groups (30 rats which have been subdivided into three groups received different doses of fluoride for eight weeks). The results of present study revealed the followings: Chlorine levels in urban area were above the allowed recommended levels, while its levels in rural areas were within the allowed level .Fluoride levels in urban areas, rural areas and bottled water were below the recommended doses. A decrease in body weight in all treated group have been observed; histopathological changes in (liver, kidney, urinary bladder and large intestine) have been observed and these changes were dose dependent. We recommended adjusting level of chlorine in both rural and urban areas to follow the world health organization recommended levels. Fluoridation programs also should be applied in Benha to cover up the low level in water
