Contaminated water is a common source of illness among travelers to Third World countries.
Another cause of alarm has been natural disasters - hurricanes, earthquakes and tornadoes - all causing concerns about safe drinking water even in the United States. Problems can range from cholera to parasites.If there's ever any doubt about the safety of the water being used, avoid it!
Third World country water systems are unreliable. Assume that all tap water is unsafe, no matter who says it's OK to drink.
Most major cities worldwide do an adequate job of purifying water much of the time.
But even where chlorination and water treatment facilities exist, pure water cannot be guaranteed. Routine disinfection of water may not kill certain disease-producing protozoa, particularly giardia and amoebic cysts. And, contamination can occur at any point in the delivery system between the treatment plant and the tap.
Another problem in many areas is the onset of the rainy season. Months of accumulated waste can be swept up and delivered to water intake and storage facilities at once. This flood of garbage and sewage frequently overwhelms treatment and delivery systems.
Water supplies from lakes, rivers and wells can be contaminated with human and animal waste. This can happen around Third World small towns, villages and farms.
"If you can't trust the water, don't trust the ice." This is a difficult rule for North Americans to observe on hot, humid tropical days and nights.
The "Journal of the American Medical Association" (June 7, 1985) reported that freezing does not completely eliminate bacteria. However, freezing for more than 24 hours does significantly reduce the bacterial count. Ice cubes melting in cola, soda water or plain water showed little or no reduction in bacterial numbers. Also, the longer ice sat in a drink melting, the higher the bacterial counts became. One conclusion from this report is that bacteria can survive freezing and can cause disease. Snow cones, popsicles and shaved ice should also be avoided.
Some airlines test the water that goes into the airplane holding tank. Water in the holding tank is usually replenished at stopovers on the plane's route. The problem with this water is that it can not be counted on 100 percent of the time. It also makes sense to avoid both the drinking water and ice cubes routinely served on flights originating from or with stopovers in Third World countries. Either request bottled mineral water or take your own bottled or purified water with you on board.
Avoid drinks that have tap water added. Avoid using tap water for brushing your teeth or rinsing your mouth. Make sure that glasses, plates and utensils are dry before using - not wet from washing. These precautions about tap water and ice cubes apply to all classes of restaurants and hotels, even the top-rated tourist facilities.
Safe water and other drinks
Canned or bottled beverages are normally OK to drink. Containers should be wiped clean and dry. Internationally known brands of carbonated beverages are usually considered the safest.
Avoid local brands of bottled soft drinks. Local bottlers may use contaminated or unpurified water for their drinks. In restaurants, an excellent way to avoid tap water as well as sugar and caffeine overload is to order soda water or mineral water. For variety, these can be flavored with limes or other citrus. The acidity from carbonation discourages bacterial growth.
Purified bottled water is also safe. However, problems arise because tap water is often misrepresented as bottled water. It's not unknown for delivery truck drivers to fill their bottles with tap water and pocket the proceeds, unbeknownst to the company. Don't trust bottled water unless you break the producer's seal from the bottle yourself.
Water purification
Water can be purified by one of three main ways: boiling, chemicals and special filters. Before using any of these methods, cloudy or dirty water should first be coarsely filtered by using an inexpensive commercial filter, clean cloth or by allowing the sediment to settle.
Boiling: This is the most reliable method to obtain safe drinking water. Boiling water at 212 degrees F kills all dangerous bacteria, viruses and parasites. A small electrical coil heater is a quick and practical way to boil water whenever electricity is available. Make sure the heater you buy is compatible with available current.
Bring the water to a vigorous boil for five minutes, then allow to cool before drinking. At high altitudes add one additional minute for every 1,000 feet of elevation.
If you have no available means of purifying water, use hot rather than cold water out of the tap. Allow it to cool to room temperature. Remember, this water may still be contaminated and should not be used regularly as a source of drinking water.
Chemical: Either iodine or chlorine can be used to treat water. Iodine is always preferable, and chlorine is used only as a last resort. Chlorine can not be counted on to kill parasites such as amoebas or giardia or certain viruses that attack the intestinal tract.
Iodine should not be used by those who are hyperthyroid or have iodine allergies. Three forms of iodine exist - 2 percent tincture of iodine, iodine crystals and tablets. Crystals and tablets carry directions on the bottle. Recent information shows that iodine tablets and crystals are only about 90 percent effective against giardia after 30 minutes of contact, and 2 percent tincture somewhat less than that. After 8 hours, however, all three are virtually 100 percent effective. Mix iodine and water at night, and you'll be set in the morning.
Crystals and tables are available at sporting goods stores and pharmacies in the United States but may be difficult to find while traveling in Third World countries. Use crystals on extended trips, since their potency doesn't decrease.
Don't use chlorine if water can be boiled or treated with iodine. Chlorine should be used in either Halazone tablet or standard liquid laundry bleach forms. Mix thoroughly and let stand for 30 minutes. If a slight chlorine odor is not detected, repeat the process and let stand for another 15-20 minutes.
Filters. Most filters have one drawback: They cannot filter out viruses, so they offer no protection against waterborne viral disease (hepatitis A, polio, diarrhea, etc.). Filters require an additional iodine chemical treatment, so there are now water filters with an additional chemical iodine used.
With preparation, you can travel almost anywhere and still have safe drinking water. A wide variety of drinks, prepared by natives of local cultures, if boiled and served hot, are usually safe depending upon how clean the utensils or containers are.
Alton Thygerson is a professor of health sciences at Brigham Young University.