Review Drinking Water Contamination and Its Effects on Human Health

Transcription

1 International Journal of Researh (IJR) e-issn: , p- ISSN: X Volume 2, Issue 12, Deember 2015 Available at Review Drinking Water Contamination and Its Effets on Human Health Vijayant Dhiman Gian Jyoti Group of Institute Shambhu Kalan Banur Abstrat: Importane of Water to Human Health and Survival Water is essential for survival. It has been stated that our existene is intimately onneted with the quality of water available to us. Aording to F. Batmanghelidj, MD, author of Your Body s Many Cries for Water, 25% of the human body is made up of solid matter while the remaining 75% is water. Therefore, If our bodies are not ontinuously supplied with water, our bodies beome dehydrated and the vital organs will deteriorate until they are no longer viable for human life. Water also ats as a purifier in our bodies. If enough water isn t onsumed, one is unable to properly flush out their kidneys and/or liver, and the olon is unable to expel bowels properly and ompletely thus keeping unhealthy toxins in the body. The longer the waste remains in the body, the more time the body has to reabsorb the toxins bak into the bloodstream. As a result, the toxins are able to make its way through the human body ausing poisoning and spreading infetions. humans. How Safe is Our Drinking Water? TOXICOLOGY: Aess to safe water is a fundamental Aording to a report by Time Magazine, over human need and, therefore, a basi human 4,000 hemials have been found in our drinking right. Contaminated water jeopardizes both water. 1 Furthermore, approximately 18 billion the physial and soial health of all people. pounds of pollutants and hemials are released It is an affront to human dignity. -Kofi into the atmosphere, soil, and groundwater in the Annan, UN Seretary-General India Aording to medial experts, an individual needs to onsume at least 2 liters of water daily for basi survival. The health and livelihood of Indian depends on the availability of a safe drinking water supply. 4 unfortunately, drinking water in the India is suseptible to toxins. As the human population and development in modern tehnology inreases, the risk for water ontamination also inreases. 5 Examples of water ontamination soures inlude animal and human waste, hemials disposed of improperly, and landfills. 5 If not treated for properly, drinking water an pose a severe health risk for 1 Routledge and Stewart (1998) 2 Global Healing Center [GHC] ( ) de Kok, Guidotti, Kjellstrom & Yassi (2001) 4 Grantham, Hairston, & MFarland (2010) 5 Environmental Protetion Ageny [EPA] 1 every year. Though the Environmental Protetion Ageny plaed more than 60 safety standards for the drinking water supply, they report that about 50% of all muniipal water supplies in the India violate Federal health standards. 1 As a result, over 120 million people have been affeted with numbers ontinuing to Available online: P a g e 1087

2 International Journal of Researh (IJR) e-issn: , p- ISSN: X Volume 2, Issue 12, Deember 2015 Available at grow. 1 Pathogens It is believed that many of the diseases assoiated with water ontamination are aused by pathogens. Pathogens spread by water leading to the spread of diseases. Examples of pathogens are bateria, viruses, and parasites. Pathogens are onsidered to be ommuniable beause they have the ability to spread from one person to another by way of ontaminated water and/or other vetors. The most ommon diseases spread through water are diarrheal diseases; examples inlude holera, typhoid, paratyphoid, salmonella, giardiasis, and ryptosporidiosis. Many pathogens arise from animal and human fees and from insuffiient water supply. Pathogen related diseases ould also be spread by person-to-person ontat, aerosols, and food intake. This auses the bateria ausing the disease to buildup over time ausing an infeted person to ontaminate the water supply and therefore ontinuing the spread of disease. For example, a survey from reported 9 disease outbreaks assoiated with drinking water, many of whih were assoiated to publi drinking water supplies. Pathogens are lassified aording to the various aspets of the environment that human intervention an alter. They inlude the following: Waterborne Diseases: Waterborne diseases arise from the ontamination of water by human and/or animal body exretions infeted by pathogeni viruses or bateria, whih are diretly transmitted when the water is onsumed or used for food preparations. Examples of waterborne diseases inlude holera, typhoid, and ryptosporidiosis. Water-Privation Diseases: Water- Privation diseases are affeted by the quantity of water. The disease is spread through (infeted) person-toperson ontat or through ontat with infeted materials. Poor personal hygiene is a ommon fator leading to water-privation diseases. Water-Based Diseases: In water-based diseases, water provides the habitat for intermediate host organisms in whih parasites are able to pass part of their life yle and later their infetive larval forms in water are passed on the humans. Water-Related Diseases: In waterrelated diseases, water provides a home for insets. Examples of these types of diseases inlude malaria, dengue and yellow fever. Water-Dispersed Infetions: In these types of infetions, pathogens are able to proliferate in freshwater and enter the body through the respiratory trat. 5 Chemials Many of the water that we drink ontain toxi hemials. These hemial substanes that are found in water is due to natural proesses or human ativities. Examples of the most ommon hemials found in water inlude the following: Arseni: Arseni is a naturally ourring Available online: P a g e 1088

3 International Journal of Researh (IJR) e-issn: , p- ISSN: X Volume 2, Issue 12, Deember 2015 Available at metal found in all lead, opper, and gold ores. The Environmental Protetion Ageny has set the aeptable standard for arseni at 10 parts per billion in tap water, however many areas exeed this limit. 2 The International Aademy for Researh on Caner (IARC) lassifies arseni as a Category I arinogen. 2 Other health risks at high levels inlude vasular disease, liver disease, skin lesions, and neurologial disorders. Fluoride: Fluoride is a natural ourring hemial found in foods and water. Fluoride is an essential element due to its importane in bone and tooth struture and growth. However, at high levels, fluoride an be toxi. Chlorine: Chlorine is often added to 2 water in order to kill bateria. If onsumed in high amounts, hlorine an be toxi and ause suffiient ell damage in the human body. 2 Iodine: Unlike some other hemials, insuffiient levels of iodine an ause lead to severe health problems suh as the enlargement of the thyroid gland, mental retardation, and retinism. Water is one of the main soures of dietary intake of iodine. Nitrates: Pestiides, nitrogenous fertilizers, and manure are the ommon soures of the presene of nitrates in water. High levels of nitrate in water an lead to blood poisoning and eventually death. ENVIRONMENTAL HEALTH RISK ASSESSMENT: The quality of water should under no irumstanes be degraded to the reommended level from a better level. The World Health Organization Water is suseptible to various toxi pathogens and hemials. Therefore, it is of extreme importane that the quality of water is tested through frequent monitoring. The quality of drinking water an be determined by its appearane, taste, and odor. Feal organisms have been deemed as a popular organism to monitor in water beause of its ability to be present in high numbers in the fees of humans and animals and beause of its ability to be easily deteted. E.Coli has been identified as a major indiator feal organism present in drinking water. Aording to standards set by the World Health Organization, no drinking water should ontain E.Coli in any 100 ml sample. Sientists are onstantly researhing how various ontaminants affet drinking water and how these 6 ontaminants affet individuals. They ontinuously study how toxi substanes affet a ommunity in order to determine the relationship between exposure to a ontaminant and a health effet. 6 Through researh and investigation, sientists are also able to determine at what level is a pathogen and hemial toxi or not. 6 The aeptable daily intake (ADI) is used to estimate risk for those toxi hemials in whih little to no adverse effets on health are observed. Available online: P a g e 1089

4 International Journal of Researh (IJR) e-issn: , p- ISSN: X Volume 2, Issue 12, Deember 2015 Available at The aeptable daily intake is a safety net when exposed to ertain toxi hemials. 6 It should also be noted that arinogens are unable to be alulated by the aeptable daily intake beause they are genotoxi hemials, have no detetable threshold for onsumption, and may be harmful at any level of exposure. The aeptable daily value is alulated by: ADI = NOAEL or LOAEL/UF NOAEL = no-observed-adverse-effet level LOAEL = lowest-observed-adverse-effet level UF = unertainty fator One the aeptable daily intake is alulated, the guideline value (GV) is determined: GV = ADI*BW*P/C BW = body weight (60 kg for adults, 10 kg for hildren, 5 kg for infants) P = fration of the ADI alloated to drinking water C = daily drinking water onsumption (2L for adults, 1L for hildren, 0.75L for infants) IMPACT ON POPULATIONS: Unfortunately, our drinking water is not as safe as we think. Drinking water is ontaminated with toxi pathogens and hemials; at last ount over 4,000 hemials have been found. 1 Soures of water ontaminants inlude human and animal feal wastes, improper disposal of hemials, natural ourring floods and other disastrous events, and use of agriultural produts suh as pestiides and fertilizers. 5 Water beomes ontaminated when it omes in ontat with these toxi pathogens and hemials. 5 The most ommon type of water ontamination is through human and animal fees. 7 Some ountries, suh as the United States have the means to safely dispose of these types of pathogens, however other ountries, suh as China and India are 6 Herman and Zaslow (1996) 7 National Resoures Defense Counil [NRDC] (1998) not able to properly dispose of the fees in a safe manner. 7 As a result, the fees enter the water supply and spread through the population through person-to-person ontat. 7 Infetions aused by pathogens are diarrheal diseases suh as E. oli, giardia and the typhoid fever. 7 Some populations are more suseptible to water-ontamination diseases more than other populations. 5 For example, hildren and infants are vulnerable to pathogen related diseases beause their immune systems are not fully developed and strong enough to fight off the toxi 7 ontaminants and the resulting infetions. Statistis show that more than 2 million hildren die from diarrheal diseases eah year with 90% of these hildren being under 5 years of age. 7 Other populations that are prone to diarrheal diseases inlude aner patients, HIV/AIDS patients, transplant patients, the elderly, and pregnant women (inluding their unborn hild). 7 Chemial toxins, pestiides, and fertilizers are also soures that ontaminate drinking water. In underdeveloped ountries, suh as Bangladesh, India, China, Taiwan, and Nepal, people drink Available online: P a g e 1090

5 International Journal of Researh (IJR) e-issn: , p- ISSN: X Volume 2, Issue 12, Deember 2015 Available at water from arseni-laed wells on a daily basis. 7 Examples of health risks that are aused by hemial ontamination of drinking water inlude skin lesions, vasular and ardia problems, and aner of the bladder, lungs, or skin, liver and kidney damage, damage to the nervous system, suppression of the immune system, and birth defets. 7 Filtration: Filtration is used to remove partiles suh as lays, organi matter and, hemials, and preipitates out of the water. 5 The proess of filtration purifies the quality of drinking water and thus dereasing the hanes of ontamination. 5 Disinfetion: The proess of disinfetion is one of the most popular and advaned treatment method of the 20thentury. 5 Disinfetion ours before water has a hane to enter the distribution enter to ensure that the water is free from toxins. and effiient soures of disinfetants inlude hlorine, hlorinates, and hlorine dioxides. 5 The most effetive way to protet the quality of drinking water is through onsistent and onstant monitoring of the drinking water supply. Before distributing water, it is important to verify that the quality of water meets the standards of safe drinking water. It is also important to ensure that there is suffiient supply of water to meet the demands of the population. Finally, it is important to know where the water is oming from before distribution. For example, if the water is oming from a well, one should verify the loation and onstrution of the well; making sure that the well and its water is proteted from surfae drainage and flooding. It is also important to keep any soure of drinking water isolated from human ativities and garbage. Treating Drinking Water Proper treatment and handling of drinking water is essential not only for the quality of water but also for human health. The type of treatment depends on several fators: the quality of the original soure of water, the number of people to whom the water will be served, and the point of origin for the water. For drinking water that does not require muh treatment or will be served to a small population (suh as to individuals within the same household), water an be treated by water purifiation filters and disinfeting tablets. Water an also be boiled to remove pathogens studies show that boiling water for one minute an remove most or all pathogeni ontaminants. 5 However, there have been warnings plaed for 5 boiling water ontaining lead and nitrate. Boiling water that ontains lead and nitrate atually inreases its onentration and therefore poses as a greater risk for infetion and poisoning. 5 It is important to keep in mind that boiling water annot be used to remove hemial toxins. Boiling water an also be expensive, espeially in plaes where fuel is limited and the population is high. In water distribution enters, 4 different methods are used to treat drinking water: floulation, sedimentation, filtration, and disinfetion: Floulation: The proess of floulation involves removing dirt and other partiles Available online: P a g e 1091

6 International Journal of Researh (IJR) e-issn: , p- ISSN: X Volume 2, Issue 12, Deember 2015 Available at that are suspended in the water. 5 This is ahieved by adding aluminum and iron salts to the water; these salts form stiky partiles, whih attrat the partiles to be removed. 5 Sedimentation: One the partiles are removed by floulation, they naturally settle out of the water. 5 advaned treatment method of the 20 th entury. 5 Disinfetion ours before water has a hane to enter the distribution enter to ensure that the water is free from toxins. 5 Effetive and effiient soures of disinfetants inlude hlorine, hlorinates, and hlorine dioxides. 5 Aording to researhers, not all organisms and ontaminants found in drinking water are harmful as long as they do not exeed safety values established by the World Health Organization. Therefore, ontaminants should be removed when absolutely neessary. 5 It is important to keep in mind that removing ontaminants is ostly; the more toxins that need to be removed, the more expensive the ost will be. 5 It is also important to remember that removing ontaminants does not seure inreased safety of human health. 5 RESEARCH NEEDS: Given that the most ommon soure of drinking water ontamination is due to pathogeni and hemial partiles, it has been advised that sientists fous on ounting the number of partiles found in drinking water. 8 Researh has shown that ounting partiles an show hanges in the quality of water whih an allow sientists to identify when it is neessary to remove to partiles and what partiles pose the greatest threats to human health. 8 Partile ounting an also help sientists determine what removal and treatment methods are neessary in order to insure the safety of drinking water. 8 CONCLUSION: Water is the essene of basi survival. Without it, life on Earth would ease to exist. In order to ensure that human life ontinues to exist, we must work together and do our part to improve the quality of drinking water. Researhers must do their part in the laboratory to ome up with treatment methods to improve the quality of drinking water. When the quality of drinking water is good, human health is also good. Referenes : [1] de Kok, T., Guidotti, T., Kjellstrom, T., and Yassi, A. (2001) Basi Environmental Health. New York: World Health Organization. [2] Environmental Protetion Ageny. Water on Tap: What You Need to Know [] Global Healing Center. The Toxins In Our Drinking Water: [4] -toxins.html [5] Grantham, D., Hairston, J., & MFarland, M. (2010) National Water Program: Drinking Water and Human Health: [6] Herman, G., and Zaslow, S., (1996). Available online: P a g e 1092