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Tap water

Mineral Water

Water of sufficient quality to serve as drinking water is termed potable water whether it is used as such or not. Although many sources are utilized by humans, some contain disease vectors or pathogens and cause long-term health problems if they do not meet certain water quality guidelines. Water that is not harmful for human beings is sometimes called safe water, water which is not contaminated to the extent of being unhealthy. The available supply of drinking water is an important criterion of carrying capacity, the population level that can be supported by planet Earth.

Typically water supply networks deliver single or multiple quality\'s of water, whether it is to be used for drinking, washing or landscape irrigation; one counterexample is urban China, where drinking water can be optionally delivered by a separate tap. In the United States, public drinking water is governed by the Safe Drinking Water Act (SDWA). Among other provisions, it protects the right of employees to report potential violations. 42 U.S.C. 300j-9(i) Within 30 days of any retaliation, a whistleblower can file a complaint with the Occupational Safety and Health Administration (OSHA).

Contents

Metabolism

Main article: Fluid balance

Water is necessary for all life on Earth. Humans can survive for several weeks without food, but for only a few days without water. A constant supply is needed to replenish the fluids lost through normal physiological activities, such as respiration, sweating and urination. Water generated from the biochemical metabolism of nutrients provides a significant proportion of the daily water requirements for some arthropods and desert animals, but provides only a small fraction of a human\'s necessary intake. There are a variety of trace elements present in virtually all potable water, some of which play a role in metabolism; for example sodium, potassium and chloride are common chemicals found in very small amounts in most waters, and these elements play a role (not necessarily major) in body metabolism. Other elements such as fluoride, while beneficial in low concentrations, can cause dental problems and other issues when present at high levels. Water is essential for the growth and maintenance of our bodies, as it is involved in a number of biological processes.

Requirement

Reference daily intake for water is 3.7 L/day for human males aged 19-30 years. Food contributes 0.5–1 L, and the metabolism of protein, fat, and carbohydrates produces another 0.25–0.4 LSwedish DFA. Thus, a person needs to drink approximately 2–3 L of water per day. These assumptions are limited by the condition of the subject, including personal health and physical exercise, but are also affected by temperature and humidity.

Access to drinking water

Drinking water vending machines in Thailand. One liter of purified water is sold (into the customer\'s own bottle) for 1 baht

Earth\'s surface consists of 70% water. Water is available almost everywhere if proper methods are used to get it. As a country’s economy becomes stronger (as its GNP per capita or PPP rise) a larger percentage of its people tend to have access to drinking water and sanitation. Access to drinking water is measured by the number of people who have a reasonable means of getting an adequate amount of water that is safe for drinking, washing, and essential household activities.

As of the year 2006 (and pre-existing for at least three decades), there is a substantial shortfall in availability of potable water in less developed countries, primarily arising from industrial contamination and pollution. As of the year 2000, 27 percent of the populations of lesser developed countries did not have access to safe drinking waterI.A. Shiklomanov, Appraisal and Assessment of World Water Resources, Water International 25(1): 11-32 (2000). Implications for disease propagation are significant. Many nations have water quality regulations for water sold as drinking water, although these are often not strictly enforced outside of the developed world. The World Health Organization sets international standards for drinking water. A broad classification of drinking water safety worldwide can be found in Safe Water for International Travelers.

It reflects the health of a country’s people and the country’s capacity to collect, clean, and distribute water to consumers. According to the United Nations\' World Health Organization (WHO) more than one billion people in low and middle-income countries lack access to safe water for drinking, personal hygiene and domestic use. These numbers represent more than 20 percent of the world’s people. In addition, close to 3 billion people did not have access to adequate sanitation facilities. (For details see data on the website of the Joint Monitoring Program (JMP) on water and sanitation of WHO and UNICEF.)

While the occurrence of waterborne diseases in developed countries is generally low due to a generally good system of water treatment, distribution and monitoring, waterborne diseases are among the leading causes of morbidity and mortality in low- and middle-income countries, frequently called developing countries.

The access to safe drinking water to the populations in several countries is listed below.Safe Drinking Water (UNICEF website article)

Table 2: Percentage of population with access to safe drinking water
Country%   Country%   Country%   Country%
Albania97 Algeria89 Azerbaijan78  Brazil87
Chile93 Cuba91 Egypt97 Iraq85
Iran92 Mexico88 Morocco80  Peru80
Syria80 Sudan67 South Africa86  Turkey82
Tunisia80 Venezuela83 Zimbabwe83   

The main reason for poor access to safe water is the inability to finance and to adequately maintain the necessary infrastructure. Overpopulation and scarcity of water resources are contributing factors.

Only forty-six percent of people in Africa have safe drinking water.

Many other countries also lack in the amount of safe drinking water that they need to survive. Some of the countries have less than twenty percent of the population that has access to safe drinking water. For example in Africa, with more than seven hundred million people, only forty-six percent of people have safe drinking water. The more populous Asia Pacific region with over three billion people, eighty percent of whom with access to drinking water, still leaves some six hundred and twenty seven million people without access to safe drinking water.[1]

The lack of water and the lack of hygiene is one of the biggest problems that many poor countries have encountered in progressing their way of living. The problem has reached such endemic proportions that 2.2 million deaths per annum occur from unsanitary water - ninety percent of these are children under the age of five. [2] One program developed to help people gain access to safe drinking water is the Water Aid program. Working in 17 countries to help provide water, Water Aid is useful in helping the sanitation and hygiene education to some of the world\'s poorest people.[3]

Bottled water regulation

In the United States, the Environmental Protection Agency sets standards for tap and public water, while the Food and Drug Administration regulates bottled water as a food producthttp://www.epa.gov/safewater/sdwa/30th/factsheets/standard.html, Federal Food, Drug,and Cosmetic Act ("FFDCA" or the "Act"), 21 U.S.C. § 301et seq., while it must meet EPA tap water standards. However, it should be noted that bottled water is not necessarily more pure, or more tested than public, tap waterEPA Frequently asked questions about water, http://www.epa.gov/safewater/faq/faq.html Standards regarding safe public water systems are based on the Safe Water Drinking ActSafe Water Drinking Act, http://www.epa.gov/safewater/sdwa/index.html

For more information regarding United States regulation of bottled water production, see Code of Federal Regulations CFR129http://www.cfsan.fda.gov/~lrd/FCF129.html

Bottled water classifications

Bottled water manufacturers must ensure that their products meet the FDA established standard of identity for bottled water products.21 C.F.R. § 165.110(a). A bottled water product identified under a specific category, such as mineral water, spring water, artesian water, etc., must meet requirements established by the government or be considered misbranded.

Code of Federal Regulations, Section 21, subsection 165.110 defines identity information for categories of bottled water:21 C.F.R. § 165.110, http://www.cfsan.fda.gov/~lrd/FCF165.html

  • drinking water - The lowest common denominator of potable water categories, meeting the basic EPA/FDA standards
  • ground water - The name of water from a subsurface saturated zone that is under a pressure equal to or greater than atmospheric pressure.
  • artesian water, also known as artesian well water - The name of water from a well tapping a confined aquifer in

which the water level stands at some height above the top of the aquifer. (Water that will rise above the water table if tapped) Artesian water may be collected with the assistance of external force to enhance the natural underground pressure.

    • How often is "artesian water" tested to meet these standards? The law says there is no mandatory testing, instead: "On request, plants shall demonstrate to appropriate regulatory officials that the water level stands at some height above the top of the aquifer."21 C.F.R. § 165.110(i)
  • mineral water - The name of water containing not less than 250 parts per million (ppm) total dissolved solids (TDS), coming from a source tapped at one or more bore holes or springs, originating from a geologically and physically protected underground water source. Mineral water shall be distinguished from other types of water by its constant level and relative proportions of minerals and trace elements at the point of emergence from the source, due account being taken of the cycles of natural fluctuations. No minerals may be added to this water.
  • purified water - The name of water that has been produced by distillation, deionization, reverse osmosis, or other suitable processes and that meets the definition of "purified water" in the United States Pharmacopeia, 23d Revision, January 1, 1995. Also may be called.
    • Alternatively, the water may be called "deionized water" if the water has been processed by

deionization, "distilled water" if it is produced by distillation, "reverse osmosis water" if the water has been processed by reverse osmosis, and "------ drinking water" with the blank being filled in with one of the defined terms.

  • sparkling water - The name of water that, after treatment and possible replacement of carbon dioxide, contains the same amount of carbon dioxide from the source that it had at emergence from the source.
  • spring water - The name of water derived from an underground formation from which water flows naturally to the surface of the earth.
    • Spring water shall be collected only at the spring or through a bore hole tapping the underground formation feeding the spring. There shall be a natural force causing the water to flow to the surface through a natural orifice. The location of the spring shall be identified.

Water Contaminates

Parameters for drinking water quality typically fall under two categories: chemical/physical and bacteriological. Chemical/physical parameters include heavy metals, total suspended solids (TSS), and turbidity. Bacteriological parameters include total coliform and fecal coliform.

Chemical parameters tend to pose more of a chronic health risk through buildup of heavy metals although some components like nitrates/nitrites and arsenic may have a more immediate impact. Physical parameters affect the aesthetics and taste of the drinking water and may complicate the treatment of bacteria, viruses, and pathogens.

Originally, fecal contamination was determined with the presence of coliform bacteria, a convenient marker for a class of harmful fecal pathogens. The presence of fecal coliforms (like E. Coli) serves as an indication of contamination by sewage. Bacteriological parameters are typically of greatest concern because of their immediate health risk.

See also

Water Portal

References

External links

Wikimedia Commons has media related to:

Water as aliment

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Drinking water

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