Methanes substituted with three halogen atoms, which may be the same or different.
Halogenated hydrocarbons refer to organic compounds containing carbon and hydrogen atoms, where one or more hydrogen atoms are replaced by halogens such as fluorine, chlorine, bromine, or iodine.
Any of several processes in which undesirable impurities in water are removed or neutralized; for example, chlorination, filtration, primary treatment, ion exchange, and distillation. It includes treatment of WASTE WATER to provide potable and hygienic water in a controlled or closed environment as well as provision of public drinking water supplies.
Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.
Means or process of supplying water (as for a community) usually including reservoirs, tunnels, and pipelines and often the watershed from which the water is ultimately drawn. (Webster, 3d ed)
Inorganic compounds that contain chlorine as an integral part of the molecule.
Substances used on inanimate objects that destroy harmful microorganisms or inhibit their activity. Disinfectants are classed as complete, destroying SPORES as well as vegetative forms of microorganisms, or incomplete, destroying only vegetative forms of the organisms. They are distinguished from ANTISEPTICS, which are local anti-infective agents used on humans and other animals. (From Hawley's Condensed Chemical Dictionary, 11th ed)
'Swimming pools' in a medical context typically refers to man-made bodies of water designed for swimming and other recreational activities, which can also serve as potential reservoirs for various infectious diseases if not properly maintained, including those transmitted through waterborne pathogens, fecal contamination, or poor water chemistry.
A group of methane-based halogenated hydrocarbons containing one or more fluorine and chlorine atoms.
Brominated hydrocarbons are organic compounds containing carbon (C), hydrogen (H) atoms, and bromine (Br) atoms, where bromine atoms replace some or all of the hydrogen atoms in the hydrocarbon structure.
The immersion or washing of the body or any of its parts in water or other medium for cleansing or medical treatment. It includes bathing for personal hygiene as well as for medical purposes with the addition of therapeutic agents, such as alkalines, antiseptics, oil, etc.
Iodinated hydrocarbons are organic compounds containing carbon and hydrogen atoms, with iodine atoms covalently bonded to them, which are used in medical imaging as radiocontrast agents.
A greenish-yellow, diatomic gas that is a member of the halogen family of elements. It has the atomic symbol Cl, atomic number 17, and atomic weight 70.906. It is a powerful irritant that can cause fatal pulmonary edema. Chlorine is used in manufacturing, as a reagent in synthetic chemistry, for water purification, and in the production of chlorinated lime, which is used in fabric bleaching.
A commonly used laboratory solvent. It was previously used as an anesthetic, but was banned from use in the U.S. due to its suspected carcinogenicity.
Rendering pathogens harmless through the use of heat, antiseptics, antibacterial agents, etc.
Water that is intended to be ingested.
The exposure to potentially harmful chemical, physical, or biological agents in the environment or to environmental factors that may include ionizing radiation, pathogenic organisms, or toxic chemicals.

Drinking water disinfection byproducts: review and approach to toxicity evaluation. (1/91)

There is widespread potential for human exposure to disinfection byproducts (DBPs) in drinking water because everyone drinks, bathes, cooks, and cleans with water. The need for clean and safe water led the U.S. Congress to pass the Safe Drinking Water Act more than 20 years ago in 1974. In 1976, chloroform, a trihalomethane (THM) and a principal DBP, was shown to be carcinogenic in rodents. This prompted the U.S. Environmental Protection Agency (U.S. EPA) in 1979 to develop a drinking water rule that would provide guidance on the levels of THMs allowed in drinking water. Further concern was raised by epidemiology studies suggesting a weak association between the consumption of chlorinated drinking water and the occurrence of bladder, colon, and rectal cancer. In 1992 the U.S. EPA initiated a negotiated rulemaking to evaluate the need for additional controls for microbial pathogens and DBPs. The goal was to develop an approach that would reduce the level of exposure from disinfectants and DBPs without undermining the control of microbial pathogens. The product of these deliberations was a proposed stage 1 DBP rule. It was agreed that additional information was necessary on how to optimize the use of disinfectants while maintaining control of pathogens before further controls to reduce exposure beyond stage 1 were warranted. In response to this need, the U.S. EPA developed a 5-year research plan to support the development of the longer term rules to control microbial pathogens and DBPs. A considerable body of toxicologic data has been developed on DBPs that occur in the drinking water, but the main emphasis has been on THMs. Given the complexity of the problem and the need for additional data to support the drinking water DBP rules, the U.S. EPA, the National Institute of Environmental Health Sciences, and the U.S. Army are working together to develop a comprehensive biologic and mechanistic DBP database. Selected DBPs will be tested using 2-year toxicity and carcinogenicity studies in standard rodent models; transgenic mouse models and small fish models; in vitro mechanistic and toxicokinetic studies; and reproductive, immunotoxicity, and developmental studies. The goal is to create a toxicity database that reflects a wide range of DBPs resulting from different disinfection practices. This paper describes the approach developed by these agencies to provide the information needed to make scientifically based regulatory decisions.  (+info)

Induction of genetic damage in human lymphocytes and mutations in Salmonella by trihalomethanes: role of red blood cells and GSTT1-1 polymorphism. (2/91)

The brominated trihalomethanes (THMs) are mutagenic and carcinogenic disinfection by-products frequently found in chlorinated drinking water. They can be activated to mutagens by the product of the glutathione S-transferase-Theta (GSTT1++-1) gene in Salmonella RSJ100, which has been transfected with this gene. To evaluate this phenomenon in humans, we have examined the genotoxicity of a brominated THM, bromoform (BF), using the Comet assay in human whole blood cultures exposed in vitro. No differences were found in the comet tail length between cultures from GSTT1-1(+) versus GSTT1-1(-) individuals (1.67 +/- 0.40 and 0.74 +/- 0.54 microm/mM, respectively, P = 0.28). The high variability was due to the relatively weak induction of comets by BF. Combining the data from both genotypic groups, the genotoxic potency of BF was 1.20 +/- 0.34 microm/mM (P = 0.003). GSTT1-1 is expressed in red blood cells but not in the target cells (lymphocytes), and expression within the target cell (as in Salmonella RSJ100) may be necessary for enhanced mutagenesis in GSTT1-1(+) relative to GSTT1-1(-) cultures. To examine this, we exposed Salmonella RSJ100 and a control strain not expressing the gene (TPT100) to the most mutagenic brominated THM detected in Salmonella, dibromochloromethane (DBCM), either in the presence or absence of S9 or red blood cells from GSTT1-1(+) or GSTT1-1(-) individuals. S9 did not activate DBCM in the non-expressing strain TPT100, and it did not affect the ability of the expressing strain RSJ100 to activate DBCM. As with S9, red cells from either genotypic group were unable to activate DBCM in TPT100. However, red cells (whole or lysed) from both genotypic groups completely repressed the ability of the expressing strain RSJ100 to activate DBCM to a mutagen. Such results suggest a model in which exposure to brominated THMs may pose an excess genotoxic risk in GSTT1-1(+) individuals to those organs and tissues that both express this gene and come into direct contact with the brominated THM, such as the colon. In contrast, those organs to which brominated THMs would be transported via the blood might be protected by erythrocytes. Such a proposal is reasonably consistent with the organ specificity of drinking water-associated cancer in humans, which shows slightly elevated risks for cancer of the colon and bladder but not of the liver.  (+info)

Case-control study of colon and rectal cancers and chlorination by-products in treated water. (3/91)

This population-based case-control study was conducted in southern Ontario, Canada from 1992 to 1994 to assess the relationship between chlorination by-products in public water supplies and cancers of the colon and rectum. Interviews providing residence and water source histories were completed by 76% of eligible cancer cases and 72% of eligible controls. Supplemental data from municipal water supplies were used to estimate individual exposure to water source, chlorination status, and by-product levels as represented by trihalomethanes (THMs) during the 40-year period before the interview. The analyses included 767 colon cases, 661 rectal cases, and 1545 controls with exposure information for at least 30 of these years (75% of subjects with completed interviews). Among males, colon cancer risk was associated with cumulative exposure to THMs, duration of exposure to chlorinated surface water, and duration of exposure to a THM level > or = 50 microg/liter and 75 microg/liter. Males exposed to chlorinated surface water for 35-40 years had an increased risk of colon cancer compared with those exposed for < 10 years (odds ratio, 1.53; 95% confidence interval, 1.13-2.09). Males exposed to an estimated THM level of 75 microg/liter for > or = 35 years had double the risk of those exposed for < 10 years (odds ratio, 2.10; 95% confidence interval, 1.21-3.66). In contrast, these relationships were not observed among females. No relationship was observed between rectal cancer risk and any of the measures of exposure to chlorination by-products. The results of this study should be interpreted with caution because they are only partially congruent with the limited amount of literature addressing this issue.  (+info)

Relation between stillbirth and specific chlorination by-products in public water supplies. (4/91)

During water treatment, chlorine reacts with naturally occurring organic matter in surface water to produce a number of by-products. Of the by-products formed, trihalomethanes (THMs) are among the highest in concentration. We conducted a retrospective cohort study to evaluate the relationship between the level of total THM and specific THMs in public water supplies and risk for stillbirth. The cohort was assembled from a population-based perinatal database in the Canadian province of Nova Scotia and consisted of almost 50,000 singleton deliveries between 1988 and 1995. Individual exposures were assigned by linking mother's residence at the time of delivery to the levels of specific THMs monitored in public water supplies. Analysis was conducted for all stillbirths and for cause-of-death categories based on the physiologic process responsible for the fetal death. Total THMs and the specific THMs were each associated with increased stillbirth risk. The strongest association was observed for bromodichloromethane exposure, where risk doubled for those exposed to a level of [greater and equal to] 20 microg/L compared to those exposed to a level < 5 microg/L (relative risk = 1. 98, 95% confidence interval, 1.23-3.49). Relative risk estimates associated with THM exposures were larger for asphyxia-related deaths than for unexplained deaths or for stillbirths overall. These findings suggest a need to consider specific chlorination by-products in relation to stillbirth risk, in particular bromodichloromethane and other by-product correlates. The finding of a stronger effect for asphyxia deaths requires confirmation and research into possible mechanisms.  (+info)

Effect of trihalomethanes on cell proliferation and DNA methylation in female B6C3F1 mouse liver. (5/91)

Trihalomethanes (chloroform, bromodichloromethane, chlorodibromomethane, and bromoform) are regulated organic contaminants in chlorinated drinking water. In female B6C3F1 mouse liver, the 4 trihalomethanes have demonstrated carcinogenic activity when administered by oral gavage; however, chloroform was not carcinogenic when administered in drinking water. Female B6C3F1 mice were administered the trihalomethanes for 11 days by gavage at 2 dose levels or in the drinking water at approximately 75% saturation. When administered by gavage, the trihalomethanes were toxic to the liver, increased the liver:body weight (bw) ratio, and increased the proliferating cell nuclear antigen-labeling index (PCNA-LI). Chloroform and bromodichloromethane were the most toxic, and they increased the liver:bw ratio the most, while bromoform and chloroform increased the PCNA-LI the most. When administered in drinking water, the toxicity of the trihalomethanes was similar to their low gavage-dose. Furthermore, only chloroform significantly increased the liver:bw ratio and bromoform and chloroform increased the PCNA-LI. Chloroform and bromodichloromethane decreased the level of 5-methylcytosine in hepatic DNA. Methylation in the promoter region of the c-myc gene was reduced by the trihalomethanes. Chloroform administered by gavage was more efficacious than given in drinking water; the efficacy of the other trihalomethanes did not differ for the 2 routes. Thus, in mouse liver, the trihalomethanes administered by gavage enhanced cell proliferation and decreased the methylation of the c-myc gene, consistent with their carcinogenic activity. Furthermore, the more modest toxicity, enhancement of cell proliferation, and decreased methylation induced by chloroform administered in drinking water correlated with its lack of carcinogenic activity. Hence, the activity of the trihalomethanes was dependent on the rate of delivery, i.e. rapid by oral gavage and more slowly in drinking water.  (+info)

Pregnancy loss in the rat caused by bromodichloromethane. (6/91)

Bromodichloromethane (BDCM), a trihalomethane, is a by-product of the chlorination of drinking water. In a recent epidemiological study, consumption of BDCM was associated with an increased risk of spontaneous abortion in pregnant women. We have previously shown that BDCM causes pregnancy loss, i.e., full-litter resorption (FLR), in the F344 rat. The mode of action was investigated, with three main findings. First, there was a dramatic difference in sensitivity between F344 and Sprague-Dawley (SD) rat strains. Following aqueous gavage treatment on gestational days (GD) 6-10, F344 rats had a 62% incidence of FLR at 75 mg/kg/day, whereas all SD rats maintained their litters. Second, the critical period encompassed the luteinizing hormone (LH)-dependent period of pregnancy. Rats treated on GD 6-10 at 75 mg/kg/day had a 75% incidence of FLR, but rats treated on GD 11-15 at 75 or 100 mg/kg/day were unaffected. Third, 24 h after a single dose, all dams with FLR had markedly reduced serum progesterone levels; however, LH levels were unaffected. The high FLR rate during the LH-dependent period, the lack of response thereafter, and the reduced progesterone levels without an associated reduction in LH levels suggests that BDCM disrupts luteal responsiveness to LH.  (+info)

Relation between trihalomethane compounds and birth defects. (7/91)

OBJECTIVES: To evaluate the risk of birth defects relative to exposure to specific trihalomethanes in public water supplies. METHODS: A retrospective cohort study was conducted based on data from a population based perinatal database in Nova Scotia, Canada and from the results of routine water monitoring tests. The cohort consisted of women who had a singleton birth in Nova Scotia between 1988 and 1995 and who lived in an area with a municipal water supply. The birth defects analyzed included neural tube defects, cardiovascular defects, cleft defects, and chromosomal abnormalities. Two of the four trihalomethane compounds occur in large enough concentrations to be analyzed (chloroform and bromodichloromethane (BDCM)). RESULTS: Exposure to BDCM at concentrations of 20 microg/l or over was associated with an increased risk of neural tube defects (adjusted relative risk (RR) 2.5, 95% confidence interval (95% CI) 1.2 to 5.1) whereas exposure to chloroform was not. Exposure to BDCM of 20 microg/l and over was associated with decreased risks of cardiovascular anomalies (RR 0.3, 95% CI 0.2 to 0.7). There was a suggestion of an increased risk of chromosomal abnormalities associated with exposure to chloroform, and no evidence of any association between either trihalomethane compound and cleft defects. CONCLUSIONS: In this cohort, differences were found in the RR associated with exposure to chloroform and BDCM for each of the congenital anomalies under study. These findings point to the importance of examining specific byproduct compounds relative to risk for these birth outcomes and in particular implicate BDCM and other correlated disinfection byproducts in the aetiology of neural tube defects.  (+info)

Use of routinely collected data on trihalomethane in drinking water for epidemiological purposes. (8/91)

OBJECTIVES: To explore the use of routinely collected trihalomethane (THM) measurements for epidemiological studies. Recently there has been interest in the relation between byproducts of disinfection of public drinking water and certain adverse reproductive outcomes, including stillbirth, congenital malformations, and low birth weight. METHOD: Five years of THM readings (1992--6), collected for compliance with statutory limits, were analysed. One water company in the north west of England, divided into 288 water zones, provided 15,984 observations for statistical analysis. On average each zone was sampled 11.1 times a year. Five year, annual, monthly, and seasonal variation in THMs were examined as well as the variability within and between zones. RESULTS: Between 1992 and 1996 the total THM (TTHM) annual zone means were less than half the statutory concentration, at approximately 46 microg/l. Differences in annual water zone means were within 7%. Over the study period, the maximum water zone mean fell from 142.2 to 88.1 microg/l. Mean annual concentrations for individual THMs (microg/l) were 36.6, 8.0, and 2.8 for chloroform, bromodichloromethane (BDCM), and dibromochloromethane (DBCM) respectively. Bromoform data were not analysed, because a high proportion of the data were below the detection limit. The correlation between chloroform and TTHM was 0.98, between BDCM and TTHM 0.62, and between DBCM and TTHM -0.09. Between zone variation was larger than within zone variation for chloroform and BDCM, but not for DBCM. There was only little seasonal variation (<3%). Monthly variation was found although there were no consistent trends within years. CONCLUSION: In an area where the TTHM concentrations were less than half the statutory limit (48 microg/l) chloroform formed a high proportion of TTHM. The results of the correlation analysis suggest that TTHM concentrations provided a good indication of chloroform concentrations, a reasonable indication of BDCM concentrations, but no indication of DBCM. Zone means were similar over the years, but the maximum concentrations reduced considerably, which suggests that successful improvements in treatment have been made to reduce high TTHM concentrations in the area. For chloroform and BDCM, the main THMs, the component between water zones was greater than variation within water zones and explained most of the overall exposure variation. Variation between months and seasons was low and showed no clear trends within years. The results indicate that routinely collected data can be used to obtain exposure estimates for epidemiological studies at a small area level.  (+info)

Trihalomethanes (THMs) are a group of chemical compounds that are formed as byproducts when chlorine or other disinfectants are used to treat water, including drinking water, swimming pools, and spas. They consist of four halogens - three of which are halogen atoms (chlorine, bromine, or iodine) and one hydrogen atom. The most common THMs formed during water treatment include chloroform, bromodichloromethane, dibromochloromethane, and bromoform.

Exposure to high levels of trihalomethanes has been linked to a variety of health problems, including an increased risk of cancer, reproductive issues, and developmental effects. As a result, regulatory agencies such as the Environmental Protection Agency (EPA) in the United States have set limits on the amount of THMs that can be present in drinking water. Regular monitoring and treatment are necessary to ensure that these limits are not exceeded and that the public is protected from potential health hazards associated with exposure to trihalomethanes.

Halogenated hydrocarbons are organic compounds containing carbon (C), hydrogen (H), and one or more halogens, such as fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). These compounds are formed when halogens replace one or more hydrogen atoms in a hydrocarbon molecule.

Halogenated hydrocarbons can be further categorized into two groups:

1. Halogenated aliphatic hydrocarbons: These include alkanes, alkenes, and alkynes with halogen atoms replacing hydrogen atoms. Examples include chloroform (trichloromethane, CHCl3), methylene chloride (dichloromethane, CH2Cl2), and trichloroethylene (C2HCl3).
2. Halogenated aromatic hydrocarbons: These consist of aromatic rings, such as benzene, with halogen atoms attached. Examples include chlorobenzene (C6H5Cl), bromobenzene (C6H5Br), and polyhalogenated biphenyls like polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs).

Halogenated hydrocarbons have various industrial applications, including use as solvents, refrigerants, fire extinguishing agents, and intermediates in chemical synthesis. However, some of these compounds can be toxic, environmentally persistent, and bioaccumulative, posing potential health and environmental risks.

Water purification is the process of removing or reducing contaminants in water to make it safe and suitable for specific uses, such as drinking, cooking, irrigation, or medical purposes. This is typically achieved through physical, chemical, or biological methods, or a combination thereof. The goal is to eliminate or reduce harmful substances like bacteria, viruses, parasites, heavy metals, pesticides, and other pollutants that can cause illness or negatively impact human health, aquatic life, or the environment.

The specific purification methods used may vary depending on the nature of the contaminants and the desired level of purity for the intended use. Common techniques include filtration (using various types of filters like activated carbon, ceramic, or reverse osmosis), disinfection (using chemicals like chlorine or UV light to kill microorganisms), sedimentation (allowing particles to settle and be removed), and distillation (heating water to create steam, which is then condensed back into pure water).

Chemical water pollutants refer to harmful chemicals or substances that contaminate bodies of water, making them unsafe for human use and harmful to aquatic life. These pollutants can come from various sources, including industrial and agricultural runoff, sewage and wastewater, oil spills, and improper disposal of hazardous materials.

Examples of chemical water pollutants include heavy metals (such as lead, mercury, and cadmium), pesticides and herbicides, volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), and petroleum products. These chemicals can have toxic effects on aquatic organisms, disrupt ecosystems, and pose risks to human health through exposure or consumption.

Regulations and standards are in place to monitor and limit the levels of chemical pollutants in water sources, with the aim of protecting public health and the environment.

I'm sorry for any confusion, but "water supply" is not a medical term per se. It is a general term used to describe the system or arrangement providing water for consumption or use, such as a public water supply system or a private well. However, in a medical context, it could refer to the source of water used in a healthcare facility for drinking, cooking, cleaning, and patient care, which must meet certain quality standards to prevent infection and ensure safety.

Chlorine compounds refer to chemical substances that contain chlorine (Cl), which is a member of the halogen group in the periodic table. Chlorine is a highly reactive element that readily forms compounds with many other elements and molecules.

Chlorine compounds can be found in various forms, including inorganic and organic compounds. Inorganic chlorine compounds include salts of hydrochloric acid, such as sodium chloride (table salt), and chlorides of metals, such as copper chloride and silver chloride. Other inorganic chlorine compounds include chlorine gas (Cl2), hypochlorous acid (HClO), and chlorine dioxide (ClO2).

Organic chlorine compounds are those that contain carbon atoms bonded to chlorine atoms. Examples of organic chlorine compounds include chlorinated solvents, such as trichloroethylene and perchloroethylene, and pesticides, such as DDT and lindane.

Chlorine compounds have a wide range of uses in various industries, including water treatment, disinfection, pharmaceuticals, agrochemicals, and manufacturing. However, some chlorine compounds can be harmful or toxic to humans and the environment, particularly if they are released into the air, water, or soil in large quantities. Therefore, it is essential to handle and dispose of chlorine compounds properly to minimize potential health and environmental risks.

Disinfectants are antimicrobial agents that are applied to non-living objects to destroy or irreversibly inactivate microorganisms, but not necessarily their spores. They are different from sterilizers, which kill all forms of life, and from antiseptics, which are used on living tissue. Disinfectants work by damaging the cell wall or membrane of the microorganism, disrupting its metabolism, or interfering with its ability to reproduce. Examples of disinfectants include alcohol, bleach, hydrogen peroxide, and quaternary ammonium compounds. They are commonly used in hospitals, laboratories, and other settings where the elimination of microorganisms is important for infection control. It's important to use disinfectants according to the manufacturer's instructions, as improper use can reduce their effectiveness or even increase the risk of infection.

I'm not able to provide a medical definition for "swimming pools" as it is not a term that is typically used in the medical field. However, swimming pools are bodies of water designed for swimming and other recreational activities. They can be found in various settings such as residential homes, community centers, hotels, and fitness clubs. Swimming pools can contain either chlorinated or saltwater and should be properly maintained to prevent the growth of harmful bacteria and algae that can cause illnesses.

If you have any medical concerns related to swimming or using swimming pools, I would recommend consulting with a healthcare professional for advice tailored to your specific situation.

Chlorofluorocarbons (CFCs) and methane are both greenhouse gases that contribute to global warming and climate change. However, they are distinct substances with different chemical structures and sources.

Chlorofluorocarbons (CFCs) are synthetic compounds made up of carbon, chlorine, and fluorine atoms. They were commonly used in refrigerants, aerosol sprays, and foam blowing agents until they were phased out due to their harmful effects on the ozone layer. CFCs have high global warming potential, meaning that they trap heat in the atmosphere many times more effectively than carbon dioxide.

Methane, on the other hand, is a naturally occurring gas made up of one carbon atom and four hydrogen atoms (CH4). It is produced by the decomposition of organic matter, such as in landfills, wetlands, and the digestive tracts of animals like cattle. Methane is also released during the extraction and transportation of fossil fuels like coal, oil, and natural gas. While methane has a shorter lifespan in the atmosphere than CFCs, it is an even more potent greenhouse gas, trapping heat at a rate 25 times greater than carbon dioxide over a 100-year period.

Therefore, while both CFCs and methane are harmful to the climate, they are distinct substances with different sources and impacts.

Brominated hydrocarbons are organic compounds that contain carbon (C), hydrogen (H), and bromine (Br) atoms. These chemicals are formed by replacing one or more hydrogen atoms in a hydrocarbon molecule with bromine atoms. Depending on the number and arrangement of bromine atoms, these compounds can have different properties and uses.

Some brominated hydrocarbons occur naturally, while others are synthesized for various applications. They can be found in consumer products like flame retardants, fumigants, refrigerants, and solvents. However, some brominated hydrocarbons have been linked to health and environmental concerns, leading to regulations on their production and use.

Examples of brominated hydrocarbons include:

1. Methyl bromide (CH3Br): A colorless gas used as a pesticide and fumigant. It is also a naturally occurring compound in the atmosphere, contributing to ozone depletion.
2. Polybrominated diphenyl ethers (PBDEs): A group of chemicals used as flame retardants in various consumer products, such as electronics, furniture, and textiles. They have been linked to neurodevelopmental issues, endocrine disruption, and cancer.
3. Bromoform (CHBr3) and dibromomethane (CH2Br2): These compounds are used in chemical synthesis, as solvents, and in water treatment. They can also be found in some natural sources like seaweed or marine organisms.
4. Hexabromocyclododecane (HBCD): A flame retardant used in expanded polystyrene foam for building insulation and in high-impact polystyrene products. HBCD has been linked to reproductive and developmental toxicity, as well as endocrine disruption.

It is essential to handle brominated hydrocarbons with care due to their potential health and environmental risks. Proper storage, use, and disposal of these chemicals are crucial to minimize exposure and reduce negative impacts.

A bath generally refers to the act of immersing or cleaning the body in a mixture of water and sometimes other substances, such as soap or essential oils. In a medical context, there are several types of therapeutic baths that may be prescribed for various purposes:

1. Sitz bath: A shallow bath that only covers the hips and buttocks, used to treat conditions like hemorrhoids, anal fissures, or other localized infections.
2. Hydrotherapy bath: A therapeutic bath using water at different temperatures, pressures, or with added substances (e.g., Epsom salts, essential oils) for relaxation, pain relief, or to improve circulation and promote healing.
3. Balneotherapy: The use of mineral-rich waters from natural springs or artificial mineral baths for therapeutic purposes, often used in the treatment of skin conditions, arthritis, or musculoskeletal disorders.
4. Medicated bath: A bath with added medical substances (e.g., medicated oils, salts) to treat various skin conditions, promote relaxation, or relieve pain.
5. Whirlpool bath: A therapeutic bath using water jets to create a swirling motion and provide hydrotherapy benefits for relaxation, pain relief, or improved circulation.

It is essential to follow medical advice when taking therapeutic baths, as incorrect usage can lead to adverse effects.

I'd be happy to help! However, it seems there might be a slight confusion in your question. Hydrocarbons and iodinated compounds are two different types of chemical substances.

Hydrocarbons refer to organic compounds consisting entirely of hydrogen and carbon atoms. They can be categorized into several types, such as alkanes, alkenes, alkynes, and aromatic hydrocarbons, based on their structure and properties.

On the other hand, iodinated compounds are organic or inorganic molecules containing iodine atoms. These compounds have various applications, especially in medical imaging and therapy, such as radioactive iodine therapy for thyroid cancer and the use of iodinated contrast agents in X-ray and CT scans.

There isn't a specific category called "iodinated hydrocarbons" since hydrocarbons don't inherently contain iodine. However, it is possible to create molecules that combine both hydrocarbon structures and iodine atoms. An example of such a compound would be iodinated alkanes, where iodine atoms replace some hydrogen atoms in an alkane molecule.

So, if you're looking for a medical definition related to iodinated compounds, I can provide that. If you meant something else, please let me know!

Chlorine is a chemical element with the symbol Cl and atomic number 17. It is a member of the halogen group of elements and is the second-lightest halogen after fluorine. In its pure form, chlorine is a yellow-green gas under standard conditions.

Chlorine is an important chemical compound that has many uses in various industries, including water treatment, disinfection, and bleaching. It is also used in the production of a wide range of products, such as plastics, solvents, and pesticides.

In medicine, chlorine compounds are sometimes used for their antimicrobial properties. For example, sodium hypochlorite (bleach) is a common disinfectant used to clean surfaces and equipment in healthcare settings. Chlorhexidine is another chlorine compound that is widely used as an antiseptic and disinfectant in medical and dental procedures.

However, it's important to note that exposure to high concentrations of chlorine gas can be harmful to human health, causing respiratory irritation, coughing, and shortness of breath. Long-term exposure to chlorine can also lead to more serious health effects, such as damage to the lungs and other organs.

Chloroform is a volatile, clear, and nonflammable liquid with a mild, sweet, and aromatic odor. Its chemical formula is CHCl3, consisting of one carbon atom, one hydrogen atom, and three chlorine atoms. Chloroform is a trihalomethane, which means it contains three halogens (chlorine) in its molecular structure.

In the medical field, chloroform has been historically used as an inhaled general anesthetic agent due to its ability to produce unconsciousness and insensibility to pain quickly. However, its use as a surgical anesthetic has largely been abandoned because of several safety concerns, including its potential to cause cardiac arrhythmias, liver and kidney damage, and a condition called "chloroform hepatopathy" with prolonged or repeated exposure.

Currently, chloroform is not used as a therapeutic agent in medicine but may still be encountered in laboratory settings for various research purposes. It's also possible to find traces of chloroform in drinking water due to its formation during the disinfection process using chlorine-based compounds.

Disinfection is the process of eliminating or reducing harmful microorganisms from inanimate objects and surfaces through the use of chemicals, heat, or other methods. The goal of disinfection is to reduce the number of pathogens to a level that is considered safe for human health. Disinfection is an important step in preventing the spread of infectious diseases in healthcare settings, food processing facilities, and other environments where there is a risk of infection transmission.

It's important to note that disinfection is not the same as sterilization, which is the complete elimination of all microorganisms, including spores. Disinfection is generally less effective than sterilization but is often sufficient for most non-critical surfaces and objects. The choice between disinfection and sterilization depends on the level of risk associated with the item or surface being treated and the intended use of that item or surface.

Drinking water, also known as potable water, is water that is safe to consume and meets the health-based standards established by regulatory agencies for human consumption. It is free from harmful levels of contaminants, including microorganisms, chemicals, radiological elements, and aesthetic factors such as taste, odor, and appearance.

Drinking water can come from various sources, including surface water (e.g., rivers, lakes), groundwater (e.g., wells), and treated wastewater that has undergone advanced purification processes. The treatment of drinking water typically involves several steps, such as coagulation, sedimentation, filtration, and disinfection, to remove or inactivate pathogens and other contaminants.

Access to safe drinking water is essential for human health, as it helps prevent various waterborne diseases and ensures proper hydration. Regular monitoring and testing of drinking water sources and distribution systems are necessary to maintain the quality and safety of the water supply.

Environmental exposure refers to the contact of an individual with any chemical, physical, or biological agent in the environment that can cause a harmful effect on health. These exposures can occur through various pathways such as inhalation, ingestion, or skin contact. Examples of environmental exposures include air pollution, water contamination, occupational chemicals, and allergens. The duration and level of exposure, as well as the susceptibility of the individual, can all contribute to the risk of developing an adverse health effect.

Look up thm in Wiktionary, the free dictionary. THM, Thm, thm or ThM may refer to: Turbo-Hydramatic, GM vehicle transmission ... ThM This disambiguation page lists articles associated with the title THM. If an internal link led you here, you may wish to ... Ton of heavy metal in a nuclear power plant Ton of hot metal in the steel industry Trihalomethanes in chemistry Therm, a unit ...
Trihalomethanes were the subject of the first drinking water regulations issued after passage of the U.S. Safe Drinking Water ... In chemistry, trihalomethanes (THMs) are chemical compounds in which three of the four hydrogen atoms of methane (CH4) are ... Many trihalomethanes find uses in industry as solvents or refrigerants. THMs are also environmental pollutants, and many are ... Trihalomethanes with all the same halogen atoms are called haloforms. Only chloroform has significant applications of the ...
Then: Thm. 4 4 R ≤ 1 R A + 1 R B + 1 R C ≤ 2 r {\displaystyle {\frac {4}{R}}\leq {\frac {1}{R_{A}}}+{\frac {1}{R_{B}}}+{\frac { ... Thm.1 k 1 ⋅ ( P A ) t + k 2 ⋅ ( P B ) t + k 3 ⋅ ( P C ) t ≥ 2 t k 1 k 2 k 3 ( ( P D ) t k 1 + ( P E ) t k 2 + ( P F ) t k 3 ... Thm.2 k 1 ⋅ ( P A ) t + k 2 ⋅ ( P B ) t + k 3 ⋅ ( P C ) t ≥ 2 k 1 k 2 k 3 ( ( P D ) t k 1 + ( P E ) t k 2 + ( P F ) t k 3 ... Thm. 1 We also have for any side a ( R − d ) 2 − r 2 ≤ 4 R 2 r 2 ( ( R + d ) 2 − r 2 ( R + d ) 4 ) ≤ a 2 4 ≤ Q ≤ ( R + d ) 2 − ...
Thm. 2.3.6-7, conditions (1,4,10). Bourgin 1983, p. 16. "Early workers in this field were concerned with the Banach space ...
Thm. 22 The distance between the circumcenter O and the orthocenter H is given by: p. 19 O H = R 2 , {\displaystyle OH=R{\sqrt ...
Thm. 2.1 from Miller, Alison. "Math 221 : Algebra notes Nov. 20". Archived from the original on 2018-08-01. Retrieved 2018-08- ...
Thm. 7 In fact, any three of the four values m, n, p, and q suffice for determination of the area, since in any quadrilateral ...
Thm. 6 As with any ellipse inscribed in a triangle △ABC, letting the foci be P and Q we have P A ¯ ⋅ Q A ¯ C A ¯ ⋅ A B ¯ + P B ... Thm. 3 The foci of the Steiner inellipse of a triangle are the intersections of the inellipse's major axis and the circle with ... Thm. 1 The axes of the Steiner inellipse of a triangle are tangent to its Kiepert parabola, the unique parabola that is tangent ...
Thm. 1.1) n-ellipses are special cases of spectrahedra. Generalized conic Geometric median J. Sekino (1999): "n-Ellipses and ...
Thm. 5 An automedian triangle is one whose medians are in the same proportions (in the opposite order) as the sides. If x, y, ...
Thm. 3.2.8 These decompositions hold separately on any compact complex manifold. The importance of the manifold being Kähler is ...
... thm.) Yamamoto, Tetsuro (2001). "Historical Developments in Convergence Analysis for Newton's and Newton-like Methods". In ...
chapter 4.2, ISBN 978-0-201-53082-7., Thm. 16.3. Cook, Stephen; Kolokolova, Antonina (2004), "A Second-Order Theory for NL", ...
Thm. 1 A skew hexagon is a skew polygon with six vertices and edges but not existing on the same plane. The interior of such a ...
Thm. 1 A regular polygon with n sides can be constructed with ruler, compass, and angle trisector if and only if n = 2 r 3 s p ... Thm. 2 Bisection Constructible number Constructible polygon Morley's trisector theorem Trisectrix Dudley, Underwood (1994), The ...
Thm. 2 These polygons are exactly the regular polygons that can be constructed with Conic section, and the regular polygons ...
Thm. 1 A cubic equation can be solved by compass-and-straightedge construction (without trisector) if and only if it has a ...
Thm. 2.6.4. ISBN 978-0-8218-0819-1. MR 1468229. Tu, L. W. (2010). An Introduction to Manifolds. Universitext. Springer. p. 25. ...
Thm. 2 A W ⋅ D Y = B W ⋅ C Y {\displaystyle AW\cdot DY=BW\cdot CY} and AD and BC are the parallel sides of a trapezoid if and ... Thm. 3 The ratio of two opposite sides in a tangential quadrilateral can be expressed in terms of the distances between the ...
"Präsidium". THM. Retrieved 15 February 2015. "Die Entwicklung von 2000 bis heute" [The development from 2000 to today]. www.thm ... "HZW in neuen Räumen". THM. Retrieved 15 February 2015. Locations of THM Studium Plus Archived 2015-03-15 at the Wayback Machine ... Increasingly, the THM is becoming more and more active with its degree programs, continuing to strive into various academic ... The University of Applied Sciences of Central Hesse (Technische Hochschule Mittelhessen (THM)) traces back to Giessen. On the ...
Also written as tan, tg.) Thm - theorem. Tor - Tor functor. Tr - field trace. tr - trace of a matrix or linear transformation ...
3.87, Thm. 3.90. Walter, Rudin. Op. cit. pp. 100, Ex. 17. Stromberg, Karl R. Op. cit. pp. 131, Ex. 3. Whitney, William Dwight ( ...
Eiswirth, M.; Kruel, Th. -M.; Ertl, G.; Schneider, F. W. (1992-05-29). "Hyperchaos in a chemical reaction". Chemical Physics ...
"Christian V. Konge og sportsmand" (in Danish). thm.d. Archived from the original on 4 February 2012. Retrieved 1 November 2012 ...
Gergeni, Matt (10 September 2013). "James Bond's "Wet Nellie" Hits Nearly $1 Million at Auction". THM Magazine. Archived from ...
P. Samuel, Lectures on Unique Factorization Domains, Thm. 6.5. P. Samuel, Lectures on Unique Factorization Domains, Thm. 6.3. P ... Idem, Thm. 6.4. See P. Samuel, Lectures on Unique Factorization Domains, P. 45-64. Hartshorne, GTM52, Example 6.5.2, p.133 and ... P. Samuel, Lectures on Factorial Rings, Thm. 5.3. "Krull ring", Encyclopedia of Mathematics, EMS Press, 2001 [1994], retrieved ...
Lemmermeyer, Thm. 7.10, p. 217 Lemmermeyer, Thm 8.15, p.256 ff Lemmermeyer Thm. 8.18, p. 260 Bach & Shallit, Thm. 6.7.1 ...
Trihalomethanes are confirmed to be carcinogenic. Throughout the five year testing period, unsafe levels of trihalomethanes ... In one of the testing periods the trihalomethanes were found at twice the EPA legal limit. Other chemicals such as lead and ... The chemicals that were most found in the water in high volumes were trihalomethanes, which is made up of four different ...
EPA (1979-11-29). "National Interim Primary Drinking Water Regulations; Control of Trihalomethanes in Drinking Water; Final ... it reacted with runoff chemicals and organic matter to form trihalomethanes (THMs). Research done in the subsequent years began ...
McGuire, M.J. and Meadow, R.G. (1988). "AWWARF Trihalomethane Survey." Jour. AWWA. 80:1, 61-68. McGuire, M.J., Lieu, N.I. and ... McGuire, M.J., and Graziano, N. (2002). "Trihalomethanes in U.S. Drinking Water: NORS to ICR." in Information Collection Rule ...
Look up thm in Wiktionary, the free dictionary. THM, Thm, thm or ThM may refer to: Turbo-Hydramatic, GM vehicle transmission ... ThM This disambiguation page lists articles associated with the title THM. If an internal link led you here, you may wish to ... Ton of heavy metal in a nuclear power plant Ton of hot metal in the steel industry Trihalomethanes in chemistry Therm, a unit ...
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Total trihalomethanes (TTHMs). Find out what is in your tap water ... EWGs Tap Water Database Total trihalomethanes (TTHMs) results ... Total trihalomethanes (TTHMs). Bedford City PWS. Trihalomethanes are cancer-causing contaminants that form during water ... The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a ... The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a ...
Def-fgl-param-thm*Def-fgl-thm*Fgl-config*Fgl-fast-alist-support*Advanced-equivalence-checking-with-fgl*Fgl-array-support*Fgl- ... Def-fgl-thm. Prove a theorem using FGL. Def-fgl-thm. is the main macro used for proving a theorem using FGL. It produces a ... def-fgl-thm. form, if there is one. *Else if the table fgl::fgl-config-table. has an entry for the keyword field name, the ... def-fgl-thm ,thmname, ,theorem-body, ,keyword-args,). However, for backward compatibility with GL, the following usage is also ...
Find trihalomethane precursor articles , the worlds largest environmental industry marketplace and information resource. ... and rivers and the effect of biodegradation on trihalomethane precursors Trihalomethane (THM) precursors are a significant ... Trihalomethane (THM) precursors are a significant problem in the San Joaquin River (SJR) watershed, an important source of ... trihalomethane precursor Articles * Disinfection byproduct formation potentials of wetlands, agricultural drains, and rivers ...
Re: THM file console error Posted: 27 Jun 21, 18:26 in response to: JeffTucker Reply ... Re: THM file console error Posted: 27 Jun 21, 18:42 in response to: davidekholm Reply ... Re: THM file console error Posted: 27 Jun 21, 18:48 in response to: JeffTucker Reply ... Re: THM file console error Posted: 27 Jun 21, 18:52 in response to: JeffTucker Reply ...
Volatile Organic Compounds - Trihalomethanes/MTBE/Nitromethane - Blood (VOCMWB_E) Data File: VOCMWB_E.xpt First Published: May ... The lower limit of detection (LLOD, in pg/mL) for whole blood - Trihalomethanes/MTBE/Nitromethane VOCs. VARIABLE NAME. SAS ... Trihalomethanes (THMs), nitromethane (NM: biomarker for halonitromethanes), and methyl tert-butyl ether (MTBE) are measured in ... Bonin MA, Silva LK, Smith MM, Ashley DL, Blount BC (2005) Measurement of trihalomethanes and methyl tert-butyl ether in whole ...
PhD Theology and ThM Theology Application Deadline: January 2. Start your application today! ...
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THM) in its distribution system, a water district in Maine installed an online... ... Due to concerns over decreasing demands and increasing annual running averages of trihalomethanes ( ... Using the online THM analyzer, BTWD created THM system distribution simulation (THM-SDS) curves using production water. The THM ... On average, the THM-100 analyzes six online samples daily and five grab samples per week. The analyzer provided THM data at a ...
Technische Hochschule Mittelhessen - University of Applied Sciences
ITH:TSX; THM:NYSE.MKT. A snapshot of the company you cannot get anywhere else ...
In this course, students learn the management skills and knowledge required to run a hotel operation. Students learn the responsibilities and managerial functions of housekeeping, engineering, front desk, and non-room revenue streams. Room revenue management, accounting practices unique to only the lodging industry, marketing and sales, and guest safety will also be included.
The ThM is designed to be completed in as little as one year. Total credit hours for the base ThM is twenty-four (24), ... The ThM is delivered in English, Korean, and Spanish languages. The ThM degree program is under the direction of the Doctoral ... DR39045 ThM Comprehensive Research (1-3 hrs)*. DR39051 ThM Practical Theology Comp Exam (1-3 hrs)* ... DR39045 ThM Comprehensive Research (1-3 hrs)*. DR39050 ThM Comprehensive Exam (1-3 hrs)* ...
Web & Digital Content Manager (THM). Posted on August 26, 2020 The HistoryMakers, a 501 (c) (3) nonprofit African American ...
Home/ College Catalog/ Course Offerings/ All Courses/ THM 285 - Dining Room Management ...
dir-international@admin.thm.de. Web:. https://www.thm.de/site/international.html. ... Technical University of Applied Sciences of Central Hesse - THMApplied Physics. *. Bachelor ...
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Committee on Guidelines for Human Embryonic Stem Cell ...
THM) getroffen hat. Im Rahmen der geplanten Transaktion werden die 40 Partner und Mitarbeitenden von THM in Großbritannien, ... Wir sind alle sehr stolz auf das, was wir als THM erreicht haben. Unser Erfolg führte dazu, dass wir regelmäßig von ... Ich kenne einige Mitglieder des THM-Teams seit vielen Jahren persönlich und weiß daher genau, was sie mitbringen und wie sie ... Seit vielen Jahren kennen wir das THM-Team, dem sein hervorragender Ruf zu Recht vorauseilt. THMs anerkannte Expertise in der ...
A French stockade erected in 1683 by LaSalle. Part of a large American history site: 6100 webpages, 86 books, 37,000 pages of print.
Find the news weve covered prior to about 2012 in our USF Health News Archive ...
... including trihalomethanes (THMs), which have been associated with adverse reproductive outcomes and bladder cancer. The U.S. ... THM water concentrations and measures of the recency since time spent in water use activities were associated with blood THM ... Factors Associated with Exposure to Trihalomethanes, NHANES 2001-2012 David L Ashley 1 , Mitchell M Smith 2 , Lalith K Silva 2 ... Factors Associated with Exposure to Trihalomethanes, NHANES 2001-2012 David L Ashley et al. Environ Sci Technol. 2020. . ...
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Metabolite thm_c in iCN900. Thiamin.
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Changes in blood trihalomethanes concentrations resulting from differences in water quality and water use activities. Arch ... Changes in breath trihalomethane levels resulting from household water-use activities. Environ Health Perspect 2006;114(4):514- ... Disinfection by-products (DBP) are a class of chemical by-products also referred to as trihalomethanes (THMs), formed when ... Disinfection By-Products (Trihalomethanes). Bromodichloromethane CAS No. 75-27-4. Dibromochloromethane (Chlorodibromomethane) ...
This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful. ...

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