Health

Dental decay and flavoured water

A laboratory study published in the International Journal of Environment and Health looks at the effects of flavoured mineral water drinks and sugar substitutes on the exogenic erosion of tooth enamel. Given that many more ...

Cardiology

Protect your heart in the heat

With much of the nation facing a heat advisory this weekend, the American Heart Association, the world's leading nonprofit organization focused on heart and brain health for all, is urging people to take precautions to protect ...

Health

How to eliminate added sugars from your diet

People are getting the message about the dangers of sugar. Nearly 70% of Americans have cut back on foods high in added sugars, according to a survey by the International Food Information Council Foundation. But there's still ...

Health

How to exercise in the summer without heat exhaustion

With a kilometer to go, triathlete Sarah True was pulled from the 2019 Ironman European Championship in Frankfurt, Germany, due to heat exhaustion. She was in the lead by seven minutes after having swum, biked and run nearly ...

Neuroscience

How a popular antidepressant drug could rewire the brain

Prozac, the trade name for the drug fluoxetine, was introduced to the U.S. market for the treatment of depression in 1988. Thirty years later, scientists still don't know exactly how the medication exerts its mood-lifting ...

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Water

Water is a ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products. Other water is trapped in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land.

Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land at the same rate as runoff into the sea. Over land, evaporation and transpiration contribute to the precipitation over land.

Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.

This text uses material from Wikipedia, licensed under CC BY-SA