Water is essential for life. It is made up of two atoms of hydrogen and one atom of oxygen.
Without water, plants, people and animals would go thirsty and die. It is as important as the air we breathe. It is believed that life began in water. It is an essential for the growth and maintenance of our bodies, as it is involved in a number of biological processes.
Importance of water
Water comprises 50 to 70 per cent of an adult's total body weight. It is lost from the body through urine and sweat, and must be replaced through our diets. Many people, though, don't consume enough and as a result may become dehydrated, causing symptoms such as headaches, tiredness and loss of concentration. Chronic dehydration can contribute to a number of health problems, such as constipation and kidney stones.
Strange as it might sound most humans do not get nearly enough water. The body gets its water from three sources:
- From drinks, either plain water or as part of other beverages.
- From solid foods, especially fruits and vegetables.
- As a by-product of chemical reactions within the body.
The British Dietetic Association advises that the average adult should consume 2.5 litres of water per day. Of this, 1.8 litres - the equivalent of six to seven glasses of water per day - must be obtained directly from beverages. This should be increased during periods of hot weather or during and after periods of physical activity.
Water is the major ingredient of all drinks: carbonated and still drinks are 65 per cent water, diluted squashes are 86 per cent water (after dilution) and fruit juices are 90 per cent water. But drinking plain water is still the most effective way of replacing lost fluids.
To achieve the daily intake of water
- Start the day with a glass of water.
- Keep water at a reachable distance at work.
- If you travel during the day, carry a bottle of water with you.
- Have lots of fresh fruit and vegetables; they have a high water content as well as many other health benefits.
- On average, each person uses over 300 litres of water at home every day. This is equal to about one full bathtub. The amount increases to about 600 litres per day when we include our indirect use of water through businesses and services that support us. If we had to retrieve this amount of water, it would take some 75 trips with a 4 L jug in each hand.
- Worldwide every minute four children die for lack of drinking water. This equals casualties of 30 fully loaded Boeing 747s crashing every day.
- The average human body is composed of about 55% water.
- Most of our food is water: tomatoes (95%), spinach (91%), milk (90%), apples (85%), potatoes (80%), beef (61%), hot dogs (56%).
- Because 70% of the Earth is covered by water, it is called the 'Blue Planet'.
- Only 2.5% of the world's water is fresh, while 97.5% is oceans.
- Even in the absence of any visible perspiration, approximately half of water loss occurs through the operation of our lungs and skin.
- Simply breathing in and out uses more than a pint of water a day. Without water, you would only expect to live for around one week.
- Water is the drink of choice for protecting your teeth and gums.
- Space explorations have found signs that water exists not only on Earth but throughout the universe.
- 92% of the energy used in washing machines is used by the hot water heater to heat water, and only 8% of the energy is actually used to run the machine. Using cold water to wash and rinse our clothes save up to 225 kg of CO2 per year.
- What is Water?
- BBC health: Nutrition - Drinks