Fluoride in drinking water

Municipal water suppliers began adding fluoride to the water in the 1940s to improve the dental health of their customers (Gessner, Beller, Middaugh, & Whitford, 1994; Hausen, 2000). Chemical additives that reach the taps in homes has long been controversial. One very good reason for concern for customers of water suppliers that add fluoride to tap water is that suppliers seem to have very inadequate control over the amount of fluoride that flows from the tap.

Simple fluoride poisoning manifests as tingling or numbness in the extremities, nausea, diarrhea, vomiting, and abdominal pain (Gessner et al., 1994).  Since at least the 1980s, assertions of a connection between drinking water fluoridation and bone cancer, particularly among children and adolescents have led to scientific studies, which seem to consistently provide no statistical support for the assertions (Levy & Leclerc, 2012). While Whiting, McDonagh, and Kleijnen (2001) found scientific studies looking at a possible relationship between fluoridation and Down’s Syndrome to be inconclusive, Lowry, Steen, and Rankin (2003), in a study in the north of England, found no statistically significant relationship between fluoridation and congenital defects.

Whether a consumer wants fluoride in their drinking water or not appears to depend on what result the consumer wants. Fluoride, in proper concentrations, does seem to improve dental health. Fluoride may have undesired consequences, but clear support for those assertions seems lacking. However, for consumers who want fluoride removed, whole home filtration using alumina or reverse osmosis are available.


Gessner, B. D., Beller, M., Middaugh, J. P., & Whitford, G. M. (1994). Acute fluoride poisoning from a public water system. The New England Journal of Medicine, 330(2), 95-99.

Hausen, H. W. (2000, October 7). Fluoridation, fractures, and teeth. BMJ: British Medical Journal (International Edition). p. 844.

Levy, M., & Leclerc, B. (2012). Fluoride in drinking water and osteosarcoma incidence rates in the continental united states among children and adolescents. Cancer Epidemiology, 36(2), e83-8. doi:http://dx.doi.org/10.1016/j.canep.2011.11.008

Mahoney, M. C., Nasca, P. C., Burnett, W. S., & Melius, J. M. (1991). Bone Cancer Incidence Rates in New York State: Time Trends and Fluoridated Drinking Water. American Journal Of Public Health, 81(4), 475-479.

Suarez-Almazor, M. E., Flowerdew, G., Saunders, L. D., Soskolne, C. L., & Russell, A. S. (1993). The Fluoridation of Drinking Water and Hip Fracture Hospitalization Rates in Two Canadian Communities. American Journal Of Public Health, 83(5), 689-693.

Whiting, P., McDonagh, M., & Kleijnen, J. (2001). Association of Down’s syndrome and water fluoride level: a systematic review of the evidence. BMC Public Health, 16-8.

Calcium and magnesium in drinking water and human health

Calcium and magnesium are the primary components in water that people associate with hard water. Many people would not notice were it not for the telltale white buildup on faucets and fixtures that people recognize as hard water residue. What you don’t like on your showerheads and faucets is essential for human health.

Water hardness seems to be inversely correlated with heart attacks (myocardial infarctions; Rubenowitz, Axelsson, & Rylander, 1996), specifically the magnesium (Rubenowitz, Axelsson, & Rylander, 1998), rather than the calcium, in the water. Calcium and magnesium, which traditional water softeners replace with sodium and potassium, is necessary for proper functioning of cells, including neuromuscular functions; magnesium activates the enzyme essential to this functioning. The heart is a muscle in humans and other animals and its proper functioning depends on magnesium, which water softeners intentionally remove.

Scientific studies find significant correlation between drinking water and cancer. Water hardness also seems to be inversely correlated with deaths from colon cancer (Yang & Hung, 1998). In this case, the primary benefactor seems to be calcium rather than magnesium in the drinking water. Yang, Chiu, Cheng, Tsai, Hung, and Lin (1999) noted that water hardness is similarly inversely correlated with esophageal cancer mortality.

Scientific research consistently finds benefits to calcium and magnesium in the human diet. For many people, the calcium and magnesium found in their municipally-supplied water in their homes is a primary dietary source. Traditional, ion-exchange water softeners replaces the calcium and magnesium that your body needs, but your fixtures do not, with sodium and potassium, which your cells also need, but which have documented detrimental side effects. A template-assisted crystallization system from Water4 Systems does not remove the calcium and magnesium, but simply converts it into a form that will not, or at least only nominally, build up on a home’s fixtures and surfaces.


Nerbrand, C., Agréus, L., Lenner, R. A., Nyberg, P., & Svärdsudd, K. (2003). The influence of calcium and magnesium in drinking water and diet on cardiovascular risk factors in individuals living in hard and soft water areas with differences in cardiovascular mortality. BMC Public Health, 321-9.

Rubenowitz, E., Axelsson, G., & Rylander, R. (1996). Magnesium in drinking water and death from acute myocardial infarction. American journal of epidemiology, 143(5), 456-462.

Rubenowitz, E., Axelsson, G., & Rylander, R. (1998). Magnesium in drinking water and body magnesium status measured using an oral loading test. Scandinavian Journal Of Clinical & Laboratory Investigation, 58(5), 423-428. doi:10.1080/00365519850186409

Yang, C. Y., Chiu, H. F., Cheng, M. F., Tsai, S. S., Hung, C. F., & Lin, M. C. (1999). Esophageal cancer mortality and total hardness levels in Taiwan’s drinking water. Environmental research, 81(4), 302-308. doi:10.1006/enrs.1999.3991

Yang, C., & Hung, C. (1998). Colon cancer mortality and total hardness levels in Taiwan’s drinking water. Archives of Environmental Contamination and Toxicology, 35(1), 148-151. doi: 10.1007/s002449900362


Solutions for Hard Water

California, Arizona, Nevada, Utah, and New Mexico are all known to have hard fresh water sources, defined as 80 or more milligrams of calcium carbonate per liter of water (see http://water.usgs.gov/owq/hardness‐alkalinity.html).   In fact, few geographic areas of the United States do not have hard water; the lucky ones include New England, most of Oregon, coastal Washington, and a long swath from Eastern Maryland, across the Carolinas and Georgia, and west to Mississippi.  Hard water clogs and damages pipes in the home and in other installations, leaves residue glassware and other household items, damages plumbing fixtures, and dries human skin.

For years, homeowners have responded to hard water by installing salt-based water softeners, which, chemically, are ion exchange systems that add even more salt into the wastewater system.  As some homeowners, and some municipalities, have installed graywater systems in their homes, in an attempt to be more conservative with their water, the high salinity of the recovered water is killing the landscaping.

In addition to the introduction of salts, beyond that found naturally or entering the water supply from agricultural and industrial sources, pharmaceuticals, pesticides, herbicides, cleaning compounds, and chlorine by-products are also an increasing problem in many water supplies.  Municipal water treatment facilities are unable to remove all of these contaminants, so the water we trust to be safe for home and other uses may not be.

Traditional water softening systems exchange sodium ions for the calcium and magnesium ions found in the water supply entering the home.  The resin that holds the sodium prior to the exchange gradually loses its ability to “soften” the water, so the resin needs to be re-charged or replaced.  Recharging the ion exchanger introduces new salts into the wastewater system, either at the residence or at an industrial facility.

A viable alternative is now available in some markets.  This alternative does not use salt to condition the water.  Template-assisted crystallization creates small, nano-crystals of calcium and magnesium salts that, once formed, remain suspended in the water rather than causing scale build-up in pipes, on housewares, and on plumbing fixtures.  Unlike some water conditioning options, a template-assisted crystallization device does not require electricity or backflushing of the system.  The system will require periodic recharging or replacing of the media.  The other selling point of a TAC-based system is that, compared to other salt-free solutions, a TAC-based system is more effective at reducing scale that builds up; any scale that accumulates on fixtures or glassware, as examples, simply wipes off.

Source:  Thomure, T., & Fox, P. (2013). Evaluation of Alternatives to Domestic Ion Exchange Water Softeners, a webinar presented by the WateReuse Research Foundation.