Drinking water becomes even more important for many people as they travel. Because travelers are usually quite active, and may be in hotter climates, their re-hydration requirements increase. This factor makes water consumption very important.
Avoid becoming dehydrated by drinking plenty of water and staying away from excessive alcohol and caffeine, which are both diuretics (dehydrators). Chapped lips and dark-yellow urine are signs that you may be low on fluids. Don't wait until you are thirsty.
The US Environmental Protection Agency reports that 90% of the world's fresh drinking water is contaminated. Identifying acceptable drinking water isn't as easy as just looking at it. Even though water may appear to be perfectly clean (like a fresh running stream), what you can't see is what will hurt you.
Tiny living and non-living materials live in all water. They are measured in microns, extremely small units invisible to the naked eye. One micron is equal to 1/1000th of one millimeter (the period at the end of this sentence is around 500 microns in size). Here are the approximate sizes of some contaminants found in water:
particles - around 100+ microns. Includes dirt, sand and sediments.
protozoa - 5 to 15 microns. Examples include giardia and cryptosporidia.
bacteria - 0.2 to 10 microns. Examples include escherichia coli (e-coli), cholera and salmonella.
viruses - 0.004 to 0.085 microns. Hepatitis A and polio are examples of viruses.
There are other pollutants in water, such as pesticides, which are too small to even measure.
When you drink water at home, it may be heavily chlorinated to kill most living matter, and it may be somewhat filtered to remove most particulates (like sediment and dirt), but there are still some microscopic organisms in the water. It's just that your digestive system is used to them being there and thus, does not become irritated or upset. But when you begin to drink water from a different source, there may be microscopic organisms in the water that your body is not yet used to. This is usually the cause of most traveler's water problems. Of course, some people have 'weaker' stomachs that are more sensitive to water differences.
Large scale water treatment may be less effective, or non-existent, in various parts of the world. Poorer drinking water conditions exist more often in the lesser-developed countries, but caution should always be taken.
Diarrhea is the most common malady suffered by travelers, and contaminated water is the most frequent source of the problem. The first thing you can do is avoid bad water. Do not drink tap water (even if it is labeled as "OK for drinking") . It's fine for showering or bathing, but don't use it for brushing your teeth. Avoid ice cubes and block ice too. Ice is usually made from tap water, and freezing does not kill the germs that can infect you - it tends to preserve microorganisms instead. And try to avoid very watery fruit such as watermelon, which may contain large amounts of potentially unhealthy water.
Buy bottled water if possible. And when you buy water, make sure that the safety-seal isn't broken. I've seen vendors in Egypt try to resell water in bottles that have already been used. They were just filling them up with tap water. If particulates are visible in the water when you shake the bottle, do not drink the water. However, it's generally safe to drink carbonated water and sodas.
Freshly brewed coffee and tea are usually safe. Boiling water for several minutes destroys pathogens but doesn't remove particles or debris. After boiling the water, you'll have to wait for the particles to sink to the bottom.
If reliable drinking water is not available, it may be necessary to properly treat water before drinking it. This can be done by boiling (as mentioned above), filtering, using chemicals or all of these methods. Boiling water every time you want drinking water is really inconvenient for most travelers, so your choices are really using chemicals and filters.
Water filters are compact, reliable, and relatively inexpensive when you consider how important they are to giving you safe drinking water. The method that each filter uses may vary, but essentially, they all involve pumping water through the filter at one end while cleaner, filtered water comes out the other. But filtering water does not automatically purify it. Here are the main differences between filtering and purifying water:
Water filters are very simple to use, but employ a very intricate design. As the water passes through the filter, small particles are trapped within the interior surface of the filter. The surfaces are made of ceramic, glass fiber or other porous material which needs to be cleaned periodically, depending on the amount of use. Some water filters also come with a membrane as a backup to ensure maximum filtration. Different pore sizes in both the membrane and the interior surface are available, depending on how much you are willing to spend. Cheaper water filters often have larger pores, which obviously let larger particles through. Smaller pore size is better. Filters can be purchased with pores small enough to trap some of the bacteria and protozoa, but to be sure and get it all, iodine and/or boiling should be used as well as filtering.
Most water filters only filter the water but do not purify it. Their pores are just too large (on a microscopic scale) to stop pathogens. But there are water filters available that have an iodine-impregnated inner core that both filters out the larger particles and kills protozoa and bacteria all in one step. PUR makes an excellent iodine-impregnated filter/purifier. The only problem with this type of system is that the pathogens really aren't exposed to the iodine for long enough periods. Therefore, iodine tablets or boiling make an excellent addition to using any type of water filter.
By using a water filter and iodine tablets, you can be sure to eliminate both particles and pathogens. Like boiling, iodine doesn't remove particles, and the tablets may take around 20 minutes to dissolve properly to be effective. Iodine has a distinct taste to it. For this reason, some water filters come with a carbon filter in them that removes the iodine taste. Iodine should not be ingested by pregnant women or people with thyroid problems. As well, long term use of iodine by anyone should be avoided.
* Remember that water filters cannot be used with salt water!