Thursday 8 July 2010
Wednesday 7 July 2010
Water consumption in UK
Revealed: the massive scale of UK's water consumption
Each Briton uses 4,645 litres a day when hidden factors are included
Weir Wood reservoir in East Sussex. Each Briton uses 4,645 litres of water a day when hidden factors are included
The scale of British water consumption and its impact around the world is revealed in a new report today, which warns of the hidden levels needed to produce food and clothing.
The UK has become the sixth largest net importer of water in the world, the environment group WWF will tell a meeting of international experts in Stockholm, with every consumer indirectly responsible for the use of thousands of litres a day. Only 38% of the UK's total water use comes from its own resources; the rest depends on the water systems of other countries, some of which are already facing serious shortages.
The study makes the first attempt to measure the UK's total "water footprint" and highlights the extent to which our imports come from countries which are running out of fresh water. It calculates that:
• Average household water use for washing and drinking in the UK is about 150 litres a person daily, but we consume about 30 times as much in "virtual water", used in the production of imported food and textiles;
• Taking virtual water into account, each of us soaks up 4,645 litres a day;
• Only Brazil, Mexico, Japan, China and Italy come higher in the league of net importers of virtual agricultural water. People in poorer countries typically subsist on 1,000 litres of virtual water a day;
• Different diets have different water footprints. A meat and dairy-based diet consumes about 5,000 litres of virtual water a day while a vegetarian diet uses about 2,000 litres.
"What's particularly worrying is that huge amounts of the food and cotton we consume are grown in drier areas of the world where water resources are either already stressed or very likely to become so in the near future," said Stuart Orr, WWF's water footprint expert.
Listen to Stuart Orr of WWF explain the report Link to this audio
With modern patterns of consumption, businesses and consumers are inadvertently contributing to the slow death of some of the world's most important rivers, the charity warns, and we may not be able to depend on the same supplies in the near future.
Experts at this week's World Water Week forum in the Swedish capital are increasingly talking of fresh water as "the new oil", a finite resource that is running out in some areas and will become more and more expensive with a knock-on impact on consumer prices.
British retailers are already examining how much of their food comes from areas where water reserves are depleted and whether they will need to relocate some of their production as water runs out.
Marks & Spencer is working with WWF to calculate the water footprint of its entire food and clothing ranges. M&S's technical director, David Gregory, said the availability of water over the next decade was already a key part of the company's strategic decisions about where to source food for its stores.
"We are already in discussion with WWF about our decisions about where to grow crops in the future," he said.
The retailer is auditing the water footprint of five key crops - strawberries, tomatoes, lettuce, potatoes and roses - to establish where and how they should be grown in the next few years to make best use of water resources. The WWF report identifies Spain, northern African countries including Egypt and Morocco, South Africa, Israel, Pakistan and Uzbekistan as countries which face acute water stress and yet supply the UK with substantial exports of their water.
Sainsbury's agronomist, Debbie Winstanley, confirmed that water would be "on every agenda in sourcing food".
"From our point of view we've got to look at where our growers are going to get their water from," she said. Most British supermarkets currently depend on southern Spain for salad crops, such as lettuce, cucumbers, tomatoes and peppers, as well as broccoli out of season through the winter months.
But over-extraction of water for horticulture and the tourist industry have led to a crisis there. Aquifers have become severely depleted and the water table has been infiltrated by the sea. "There are massive challenges with water in places like Murcia [southern Spain]. We have to look at least 10 years ahead in terms of security of supply. Murcia will have to look very different in five years' time.
"We'll have to look at new desalination technologies, and we may have to look at crops that can cope with more saline conditions, such as broccoli. We take tomatoes out of Morocco in winter, and we've looked very hard at Moroccan water, but it's complex; if you use more greenhouse production here it uses more energy. Peas and beans are a steady all-year market. We've got to think about how we get them here in a responsible manner," she said.
Factors that influence water needs
You may need to modify your total fluid intake depending on how active you are, the climate you live in, your health status, and if you're pregnant or breast-feeding.
• Exercise. If you exercise or engage in any activity that makes you sweat, you need to drink extra water to compensate for the fluid loss. An extra 400 to 600 milliliters (about 1.5 to 2.5 cups) of water should suffice for short bouts of exercise, but intense exercise lasting more than an hour (for example, running a marathon) requires more fluid intake. How much additional fluid you need depends on how much you sweat during exercise, and the duration and type of exercise. During long bouts of intense exercise, it's best to use a sports drink that contains sodium, as this will help replace sodium lost in sweat and reduce the chances of developing hyponatremia, which can be life-threatening. Also, continue to replace fluids after you're finished exercising.
• Environment. Hot or humid weather can make you sweat and requires additional intake of fluid. Heated indoor air also can cause your skin to lose moisture during wintertime. Further, altitudes greater than 8,200 feet (2,500 meters) may trigger increased urination and more rapid breathing, which use up more of your fluid reserves.
• Illnesses or health conditions. When you have fever, vomiting or diarrhea, your body loses additional fluids. In these cases, you should drink more water. In some cases, your doctor may recommend oral rehydration solutions, such as Gatorade, Powerade or CeraLyte. Also, you may need increased fluid intake if you develop certain conditions, including bladder infections or urinary tract stones. On the other hand, some conditions such as heart failure and some types of kidney, liver and adrenal diseases may impair excretion of water and even require that you limit your fluid intake.
• Pregnancy or breast-feeding. Women who are expecting or breast-feeding need additional fluids to stay hydrated. Large amounts of fluid are used especially when nursing. The Institute of Medicine recommends that pregnant women drink 2.3 liters (about 10 cups) of fluids daily and women who breast-feed consume 3.1 liters (about 13 cups) of fluids a day.
Source| http://www.mayoclinic.com
Tuesday 6 July 2010
How much water should you drink everyday?
Water: How much should you drink every day?
Water is essential to good health, yet needs vary by individual. These guidelines can help ensure you drink enough fluids.
How much water should you drink each day? It's a simple question with no easy answers. Studies have produced varying recommendations over the years, but in truth, your water needs depend on many factors, including your health, how active you are and where you live.
Although no single formula fits everyone, knowing more about your body's need for fluids will help you estimate how much water to drink each day.
Health benefits of water
Water is your body's principal chemical component and makes up about 60 percent of your body weight. Every system in your body depends on water. For example, water flushes toxins out of vital organs, carries nutrients to your cells and provides a moist environment for ear, nose and throat tissues.
Lack of water can lead to dehydration, a condition that occurs when you don't have enough water in your body to carry out normal functions. Even mild dehydration can drain your energy and make you tired.
How much water do you need?
Every day you lose water through your breath, perspiration, urine and bowel movements. For your body to function properly, you must replenish its water supply by consuming beverages and foods that contain water.
So how much water does the average, healthy adult living in a temperate climate need? In general, doctors recommend 8 or 9 cups. Here are the most common ways of calculating that amount:
- Replacement approach. The average urine output for adults is about 1.5 liters (6.3 cups) a day. You lose close to an additional liter (about 4 cups) of water a day through breathing, sweating and bowel movements. Food usually accounts for 20 percent of your total fluid intake, so if you consume 2 liters of water or other beverages a day (a little more than 8 cups) along with your normal diet, you will typically replace your lost fluids.
- Eight 8-ounce glasses of water a day. Another approach to water intake is the "8 x 8 rule" — drink eight 8-ounce glasses of water a day (about 1.9 liters). The rule could also be stated, "Drink eight 8-ounce glasses of fluid a day," as all fluids count toward the daily total. Although the approach really isn't supported by scientific evidence, many people use this easy-to-remember rule as a guideline for how much water and other fluids to drink.
- Dietary recommendations. The
Even apart from the above approaches, if you drink enough fluid so that you rarely feel thirsty and produce 1.5 liters (6.3 cups) or more of colorless or slightly yellow urine a day, your fluid intake is probably adequate. If you're concerned about your fluid intake, check with your doctor or a registered dietitian. He or she can help you determine the amount of water that's best for you.
Monday 5 July 2010
Access to drinking water World Map
Source| World Health Organization and United Nations Children's Fund. 2000. Accessed through the United Nations Common Database in 2006. Online at: http://unstats.un.org/unsd/cdb/
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