Clean drinking water

Drinking water, also known as potable water or improved drinking water, is water that is safe to drink or to use for food preparation, without risk of health problems. Globally, in 2015, 89% of people had access to water suitable for drinking. Nearly 4.2 billion had access to tap water while another 2.4 billion had access to wells or public taps. 1.8 billion people still use an unsafe drinking water source which may be contaminated by feces. This can result in infectious diseases, such as gastroenteritis, cholera, and typhoid, among others.

Water is essential for life. The amount of drinking water required varies. It depends on physical activity, age, health issues, and environmental conditions. It is estimated that on an average, an American drinks about one litre of water a day with 95% of them drinking less than three litres per day. For those who work in a hot climate, up to 16 liters a day may be required. Water makes up about 60% of the body weight in men and 55% of weight in women. A baby is composed of about 70% to 80% water while the elderly is composed of around 45%.

Typically in developed countries, tap water meets drinking water quality standards, even though only a small proportion is actually consumed or used in food preparation. Other typical uses include washing, toilets, and irrigation. Greywater may also be used for toilets or irrigation. Its use for irrigation however may be associated with risks. Water may also be unacceptable due to levels of toxins or suspended solids. Reduction of waterborne diseases and development of safe water resources is a major public health goal in developing countries. Bottled water is sold for public consumption in most parts of the world.

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Wikipedia