Tap water is obtained either from surface water - water that run off from ponds, rivers, and lakes, and is collected in reservoirs- or from ground water, such as wells.
Tap water contains calcium and magnesium. It can be considered "hard" or "soft", depending on its geographic origins. Hard water prevents soap from lathering and results in filmy sediment being deposited on hair, clothing, pipes, dishes etc. It can be annoying. Some studies have shown that the incidence of death from heart disease may be lower in areas where the drinking water is hard, although results have not been conclusive.
Soft water can be naturally soft or it may be hard water that has been treated to remove the calcium and magnesium. Soft water has a tendency to dissolve the lining of pipes. Copper, zinc, and arsenic are toxic metals that can leak into softened water from copper pipes. Drinking unfiltered tap water could be hazardous to your health. Here are some specific reasons:
1. Safety
Most tap water is safe. Occasional contamination is unavoidable. It has been reported that 10% of the serious gastrointestinal illness case in children requiring hospital visits are attributable to the drinking water, according to researchers at the Harvard School of Public Health. Adults with weakened immune systems are also at risk, including those with AIDS, cancer patients undergoing chemotherapy or radiation treatment, or the elderly. Contaminants in water above the level set by the EPA are often the cause.
2. Chlorination
Seventy percent of Americans drink chlorinated water. Chlorine is added to most municipal water supplies. It destroys waterborne bacteria; including those that result in typhoid fever, cholera, and dysentery.
Studies have shown that lifetime consumption of chlorinated tap water can more than double the risk of bladder and rectal cancer in certain individuals. It appears that the chlorine reacts with naturally found organic compounds to form "chlorination byproducts", many of which are carcinogenic. Studies have also found that rectal cancer for both sexes escalated with duration of chlorinated water.
In addition to cancer, research has linked chlorine-based chemicals to infertility and other reproductive problems. The chemical structure of some chlorine-based chemicals are similar to that to estrogen. These may act as a competitor to block the action of natural estrogen, or in some case, actually amplifying its effect.
3. Low Dose Industrial Toxins and Pharmaceutical Products
Industrial toxins and pharmaceutical products in extreme low dosage escape the water treatment plant and may be found in tap water, although at a much lower level than that which causes pharmacological results. Many waters contained arsenic, nitrates, or other inorganic contaminants at levels below current maximum safety standards. Studies have shown that it is not infrequent to find waters containing synthetic organic chemicals - such as the industrial chemicals toluene or xylene, or chemicals used in manufacturing plastics such as phthalate or styrene. Pharmaceutical products can have long half-lives. They accumulate, reaching detectable and biologically active amounts. Several commonly used medicinal drugs, such as erythromycin, naproxen, and sulpha-methoxazole, can persist in the environment for more than a year. Clofibric acid, the main metabolite of clofibrate, has an estimated persistence in the environment of 21 years and is still detectable in lakes and rivers even after its withdrawal from the market.
4. Fluoridation
Over 50% of the US population drinks fluoridated water, ostensibly to improve dental health. The Center for Disease Control is advocating this based on data that is half a century old. Whether it is good for our health has been a hotly debated issue for years. Conclusive evidence to prove that fluoride actually works is lacking. On the other hand, a considerable amount of data exists to show that fluoride is a negative fountain of youth.
What we do know is that is that population areas of high fluoride intake is associated with increased incidence of Down syndrome, cancer, osteoporosis, osteomalacia, mottled teeth, and death from all course. One study found that fluoride elevates cancer mortality by 17% in large cities. Over 60,000 cancer deaths in USA may be related to fluoridation each year according to some epidemiological studies.
In many European countries where fluoride is banned, the rate of dental cavity actually decreases. For example, researchers studied more than 15,000 children in the formerly fluoridated German towns of Spremberg and Zittau and showed a 38 percent and 20 percent reduction in cavities respectively after fluoridation is stopped and the fluoride concentration in the water dropped from 1 ppm to below 0.2 ppm.
What we do know is that fluoride causes cell death (apoptosis) in the human leukemia cells by activating certain enzymes that have been identified as a key mediator of apoptosis of cells in humans and other mammals, leading to DNA damage and cellular change. This is dose-dependent and time dependent. Studies have shown a significant increase in chromosome aberrations at the chromatid level, sister chromatid exchanges, and unscheduled DNA synthesis induced by sodium fluoride. In addition, fluoride has been shown to inactivate over 60 enzymes, disrupt the immune system, and inactivate vitamin C. In short, it is an anti-nutrient.
Much of the reasoning behind fluoridating water was to prevent tooth decay. As far as dental care, it should be remembered that prevention of tooth decay rest primarily on sound nutrition. Tooth brushing and fluoride does not stop rampant tooth decay if the diet is unhealthy. Fluoride only hardens the outer surface of the enamel and may prevent calcium from being deposited when a tooth is re-mineralized. The key to good dental hygiene is to eat a proper diet and drink plenty of pure, non-fluoridated filtered water.
Most people do not know that plain "fluoride" does not exist in our water. The naturally occurring form of fluoride, calcium fluoride, is not toxic - but this form is not used to fluoridate water. The chemicals used to fluoridate over 90% of the in the US are one of the silicofluorides (either fluosilicic acid or sodium silicofluoride, not sodium fluoride). Sodium hydrofluorosilicic acid is one of the most reactive chemical species know to man. Its toxicity is well known. This is added to our water to produce "healthy teeth". Very little long-term research has been done on fluorosilicates, that which is what is poured into the drinking water.
Equally sad, nobody really knows for sure what concentration of fluoride is considered toxic. Fluorides are the 13th most widely distributed element on earth, so it can turn up almost anywhere. Individuals have different levels of tolerance for toxins such as fluoride. Until more is known, it is only prudent to expect that some level of cell damage is present with fluoridated water.
5. Aluminum
Aluminum in drinking water has been linked to Alzheimer's disease. In a study where close to 2,700 individuals were followed for an 8-year period to identify new cases of probable Alzheimer's, researchers found that that a concentration of aluminum in drinking water above 0.1 mg/l may be a risk factor of dementia and Alzheimer's disease. It is interesting to note that some water treatment facilities actually add aluminum sulfate to remove particulate and organic matter.
The relationship between aluminum and fluoride is very interesting. The body does not readily absorb aluminum by itself. However, in the presence of fluoride ions, the fluoride ions combine with the aluminum to form aluminum fluoride, which is absorbed by the body. In the body, the aluminum eventually combines with oxygen to form the end product aluminum oxide or alumina. Alumina is found in the brains of patients with Alzheimer's disease.
Studies have shown that rats fed alumina in diet results in short term memory loss, unsteady gait, and loss of structures of the neo-cortex and hippocampus, all symptoms consistent of Alzheimer's disease.
6. Parasites
Giardia (G. lambia) and Cryptosporidium (C. parvum) are waterborne protozoan cysts that may be present in some water supplies. When ingested, the cyst-shell is shed and the organisms infect the intestines, causing illnesses. Because Giardia and Cryptosporidium cysts are resistant to traditional disinfection agents such as chlorine and ultraviolet light, the organisms are often not removed by municipal water treatment.
Ingestion of water infected with Cryptosporidium cysts causes Cryptosporidiosis, a disease characterized by symptoms such as diarrhea, nausea, vomiting, abdominal cramps, headaches, and low-grade fevers. Symptoms may last from one to two weeks before the body's immune system stops the infection. Young children, older adults, and those with weakened immune systems face greater risk of serious illness and possible death resulting from infection. Cryptosporidiosis was brought to national attention in 1993 when the city of Milwaukee's water supply became contaminated with Cryptosporidium cysts, resulting in 400,000 cases of the disease and 100 related deaths.
Ingestion of water infected with Giardia cysts results in Giardiasis (commonly know as "beaver fever"), one of the most common causes of diarrhea in North America. Infection is more common among children and may last for up to three weeks. Giardiasis may be effectively treated with antibiotics. There currently is no truly effective antibiotic treatment for cryptosporidiosis, but the disease will generally subside on its own. However, persons having compromised immune systems may have chronic cryptosporidiosis that may persist for months.
Carbon block filters will remove Crytosporidium and Giardia cysts. Boiling water will also achieve the same. Look for filters that are capable of removing particles less than 1 micron in diameter. Reverse osmosis filtration devices will also remove Cryptosporidium oocysts from drinking water.
If you have to take tap water, consider placing tap water in a glass or ceramic pitcher in the refrigerator, with the top loose to allow the chlorine to dissipate overnight before drinking. This also will allow volatile disinfection by-products to evaporate (though less volatile disinfection by-products may stay in the water). Overnight refrigeration of tap water in a loosely capped container also reduces the objectionable chlorine taste and odor.