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Pm 1813

WATER’S ROLE IN THE BODY Water, pure and calorie-free, is the best beverage to quench thirst. But, water is much more than just a refreshing beverage. Water: Is a valuable nutrient essential for survival Is the most abundant substance in the body Is present in all tissues in varying proportions: blood is 92 percent water, muscles are 75 percent water, and bones are about 25 percent water. Is required to carry nutrients and oxygen to the cells. Is required to remove waste from the cells Helps regulate body temperature Helps absorb food nutrients and convert them into energy Is crucial for the many life-supporting chemical reactions that constantly occur throughout the human body. Water cannot be stored in the body. That’s why recommendations are to drink at least six to eight 8 ounce glasses of water daily. This amount is necessary—even when you don’t feel thirst—to replenish water losses and maintain healthy kidney function.

WHY BOTTLED WATER? Some consumers like the convenience of carrying bottled water with them when they travel or go about their daily routines. Others are concerned about the safety and quality of tap water. Whatever the reason, the use of bottled water has increased. Public drinking water is generally safe and public water works staff attempt to keep it that way. But industrial plants and agricultural chemicals can contaminate nearby municipal and private water sources. Bacteria is one concern. For healthy individuals, bacteria are not a major health threat, and chlorination of drinking water or boiling it for about one minute easily kills bacteria. Chlorine is a very effective disinfectant. Most Iowa communities add chlorine in the minimal amounts necessary to meet standards set by the state Department of Natural Resources. Research, however, suggests that prolonged exposure to chlorination by-products is associated with an increased risk of certain types of cancer. Pesticides are a much greater concern, especially for rural populations whose water supply comes primarily from private wells that are not subject to environmental and health regulations by government agencies. Exposure to lead and some copper pipes are another possible source of water contamination. Lead, for example, may decrease learning abilities of your children and contribute to kidney damage and elevated blood pressure in adults. The toxic effects of contaminants are particularly harmful to children, the elderly, and people with weakened immune systems. If any of these possibilities are a concern, switching from tap to bottled water may be an alternative. However, one should not assume that whatever comes in a bottle is automatically high quality. BOTTLED WATER (PROS) Bottled water may have a better smell and taste because of the blend of minerals and method of processing. In addition, plastic bottles are light and convenient to carry. Chlorine is not used as a disinfectant. Instead, bottled water is treated by ultraviolet irradiation, filtration, and ozonation. These methods effectively kill most waterborne bacteria and leave no aftertaste. Some brands of bottled water (particularly those imported from Europe) contain relatively high concentrations of minerals such as calcium and magnesium. Calcium is essential for strong bones, nerve

impulse transmissions, control of muscle contraction, and secretion of hormones and digestive enzymes. Magnesium helps strengthen the immune system and regulate blood pressure. Although dairy products are major sources of calcium, and fruit and vegetables provide magnesium, bottled water also can help to meet the daily requirements for these minerals. Bottled water is classified as food and, therefore, regulated by the Food and Drug Administration (FDA). The FDA standards for bottled water quality are similar to those established by the U.S. Environmental Protection Agency (EPA) for tap water. Some bottlers are members of the International Bottled Water Association (IBWA) and, thus, must pass an annual inspection of their products as well as their bottling facilities by the National Sanitation Foundation (NSF International) that has stricter requirement than FDA. Bottled water imported from Europe is subject to additional regulations set by the European Union. BOTTLED WATER (CONS) Fluoride content of most bottled waters is low. Fluoride is an important nutrient, especially in early childhood, for strong tooth and bone development. On average, children (1-3 years old) require 0.7mg of fluoride per day, and adults need about 3.4 mg/day. A few bottled waters have fluoride content that exceeds children’s recommended daily intake and could cause mottling of the teeth. Bottled water sources are vulnerable to agricultural or industrial pollutants. The safety and quality of bottled water produced in the U.S. are largely regulated by state governments with widely varying standards. In contrast, municipal water supplies have nationally uniform regulations and are monitored daily for pesticides and many other contaminants. Some brands of bottled water have high sodium content. Many Americans consume on average 1.5 to 3 times the recommended daily sodium intake (2,400 milligrams). Bottled water that has more than 10 mg/liter of sodium is not a good choice for people suffering from hypertension or heart or kidney ailments. Packaging may be a potential health risk. The types of packaging material are indicated on each bottle. Plastic bottles made from polyvinyl chloride (PVC) or polyethylene (PET, HDPE, PE) are widely used for all types of water in many countries. Research has shown that the leeching of components from plastic bottles into the water increases with storage time at or above room temperature. Some of these components may be carcinogenic, for example vinyl chloride in PVC bottles. Research in this area is limited. Bottlers are not required to put manufacturing dates on their products. Thus, consumers cannot determine how long bottled water has been on the supermarket shelf. Bottled water is not sterile (an exception is baby drinking water) and contains trace amounts of bacteria naturally present or introduced during processing. Bottled water is more expensive than drinking water from municipal sources.

TIPS FOR BUYING AND STORING BOTTLED WATER Read the label carefully. It should say, “bottled at the source,” and specify a location of the source. Unless a location is indicated on the label, “spring water” could be tap water with minerals added to improve taste. Check the mineral content. The ideal water is high in magnesium (at least 90 mg/liter) and calcium (twice the amount of magnesium) and low in sodium (less than 10 mg/liter). Some manufacturers do not list mineral content on the label, especially if only negligible amounts of minerals are present. For water low in sodium, look for label claims such as “sodium free” or “low sodium.” Parents who rely on bottled water to prepare infant formula should check the water’s fluoride content. If the amount is low, as it is in distilled water, dietary fluoride supplementation is necessary to ensure normal tooth development. Check if the bottler is a member of IBWA. The words “Member of IBWA” on the label is a guarantee that the levels of any contaminants, if present, are below FDA standards. However, even if a bottler is not a member of IBWA, the product may still be safe and of good quality. Whenever possible, buy refrigerated bottled water and keep it refrigerated. Storage at or above room temperature promotes bacterial growth and increases leeching of plastic contaminants from the container into water.

Carbonated (sparkling) water contains fewer bacteria. Carbonation increases the acidity of water which, in turn, has a bactericidal effect. If you are reusing a bottle, make sure it is thoroughly washed, especially its rim. TYPES OF BOTTLED WATER Supermarkets sell many different kinds of bottled water. Artesian water comes from a confined, underground water source. Distilled water is water that has been evaporated and allowed to condense, which removes all minerals and contaminants. Drinking water is tap water that has been filtered and disinfected by water treatment plants. Natural mineral water contains only the minerals present in the water as it flows from the ground. Mineral water not labeled “natural” may have had minerals added or removed. Sparkling water is any water that contains naturally occurring or added carbon dioxide. Many brands of mineral water, spring water, and other bottled waters are marketed as sparkling water. Spring water comes from an underground source from which water flows naturally to the surface. Well water is brought to the surface by pumps from an aquifer (a water-bearing rock or soil formation located underground). Manufacturers are allowed to add very small amounts of flavors (lemon, raspberry, etc.) or other additives to their bottled water products. REF: Bottled Water---to drink or not to drink? Pm 1813. March 2000.

QUESTION: Is it safe to reuse single service plastic water (or soda) bottles? ANSWER: Yes, with care. The reuse of single service plastic bottles and the potential for migration of carcinogens from the plastic into the water is blown way out of proportion. Research has shown that the highest level of carcinogens found in water from reused plastic bottles is in the part per billion range. The risk assessment indicates that the level is below concern levels for cancer. Additional research on solarized PET bottles showed that the levels of the compounds of concern was very low—in the sub parts per billion range. Therefore, the concern about carcinogens is not warranted; however, there is some indication that reused water bottles may have significant bacterial contamination. Proper sanitation of water bottles is important in maintaining water quality. This means washing completely with detergent, rinsing well and allowing to air dry. A simple sanitizing step would be 4-5 drops of bleach in a full bottle followed by air drying. REF: Dr. Samuel Beattie, Extension Food Science Specialist, 8/03;

Prepared by Iowa State University FAMILIES EXTENSION ANSWER LINE 800-262-3804 in Iowa 800-854-1678 in Minnesota

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