If you’re anything like me, you have been consuming tap water on a regular basis without a thought about the possible negative implications.
Until recently, I did not think much of the health effects of drinking tap water regularly, besides that it is so convenient and cheap.
Unfortunately, this has changed.
In this article, you will learn how safe (or unsafe) drinking tap water is, pros and cons of fluoride and other minerals that are added to the water supply, and the best ways to filter your water.
**NOTE** The information in this article is relevant to the U.S. For all you others—I’m talking to you Norwegians and Austrians—go enjoy your perfect tap water in peace.
The short answer is no.
But it’s complicated.
Because minerals also have many health benefits.
According to the USDA Nutrient’s Data Laboratory, sodium, potassium, calcium, magnesium, iron, copper, manganese, phosphorus, and zinc were found to be present in a nationally representative sampling of drinking water.
According to the study, only 4 of the minerals were above 1% of the U.S. Daily Value, assuming that 2 liters of tap water were consumed daily.
The 4 minerals were copper at 10%, calcium at 6%, magnesium at 5%, and sodium at 3%.
There are many known benefits of mineral consumption.
Calcium and magnesium have shown bone and cardiovascular health advantages.
Sodium intake is important for electrolyte balance.
Copper’s health benefits include antioxidant properties, helping your body utilize iron effectively, and cardiovascular health.
According to the Environmental Protection Agency, fluoride is also found in tap water.
Why is that, you ask?
Well, in 1974, Congress passed the Safe Drinking Water Act (article about the Safe Drinking Water Act can be found here), and determined the level of contaminants at which no adverse health effects were likely to occur.
They called this the Maximum Contaminant Level Goal or MCLG for short.
The MCLG for fluoride is 4.0 mg/l.
According to the Center for Disease Control and Prevention, 73.9% (204.3 million people) of the population in the U.S. population on community water systems had access to fluoridated water in 2010.
Before we go into the potential negative implications, let’s start with the positive.
Fluoride is often added to the water supply for its positive effect on our dental hygiene.
It helps build strong teeth, prevents cavities, and supports healthy tooth enamel that acts as a protective barrier against harmful bacteria that harm our teeth and gums.
Now for the bad…
One potential negative effect of consuming fluoride-filled tap water fluoride consumption is fluorosis.
Fluorosis is the disturbance of dental enamel during tooth development, caused by excess fluoride consumption.
I did some research and found the following studies showing fluoride’s effect on fluorosis.
One study conducted at the University of Iowa concluded that when infants consume beverages, specifically infant formulas prepared with fluoridated water, they have a much higher risk of developing fluorosis in their primary teeth
Another study conducted on 320 children attending elementary school in Campeche, Mexico showed an occurrence of fluorosis in 56.3% of the children caused by exposure to fluoride.
In addition, a study conducted by the CDC showed that despite 60 years of water fluoridation reaching about 2/3 of Americans on public water supplies and almost 100% being reached via food supply, there is still an incidence rate of 1/3 to ½ of U.S. schoolchildren exhibiting dental fluorosis.
Not totally relevant, but in my research I also came across this study that showed that children who breastfeed have less cavities than those who use formula. This is despite the fact that breast milk has 100 times less fluoride than baby formula.
Fluoride has been known to have negative effects on teeth, bones, and stomach.
In a study conducted on rats to determine the effects of fluoride ingestion, Sprague-Dawley rats consumed a diet high in fluoride for up to 99 weeks.
The study showed evidence of fluoride toxicity in the teeth, bones, and the stomach. Severity of the side effects were directly related to the quantity and duration of the fluoride consumption.
Fluoride has also been found to affect neurodevelopment of children as well as adults and rodents.
According to the Harvard School of Public Health, high levels of fluoride consumption were shown to cause neurotoxicity in adults and have negative impacts on memory and learning in rodent studies.
In the study, researchers from the Harvard School of Public Health and China Medical University in Shen Yang combined 27 studies on the effect of fluoride’s effect on children’s neurodevelopment.
The study, published in 2012, showed possible adverse effects on cognitive development in children.
In the study, IQ measures were taken from over 8,000 children of school age and all but one of the studies conducted on these school children suggested that high fluoride content in water may have negative effects on cognitive development.
The average deduction in IQ score was 7 IQ points and showed that children in high-fluoride areas had much lower IQ scores than those who lived in low-fluoride areas.
Harvard School of Public Health professor, Philippe Grandjean, went as far as to state that “Flouride seems to fit in with lead, mercury, and other poisons that cause chemical brain damage. The effect of each toxin may seem small, but the combined damage on a population scale can be serious, especially because the brainpower of the next generation is crucial to all of us.”
Fluoride intake is not the only reason to avoid consuming tap water.
Tap water can have levels of bacteria. As a result, chemicals such as chlorine are added to help kill the bacteria and make the water safer.
This ins’t a big deal in small quantities. Chlorine is actually my filtration of choice when camping. However, consumption in high quantities is not ideal.
Every city’s tap water will be different.
To figure out what is in your local tap water, contact your water supplier directly.
Water suppliers that serve the same people year round and are required to send their customers an annual water quality report.
So now that we are more aware of the amount of minerals found in our public water supply, the next portion of the article will be talking about the other minerals found in tap water: magnesium, calcium, zinc, sodium, and copper.
Magnesium has been shown to have many positive effects, and according to the World Health Organization, drinking water rich in magnesium may provide substantial contributions to different communities.
Low magnesium levels have been associated with endothelial dysfunction, decreased insulin sensitivity, hypertension, pre-eclampsia, coronary heart disease, type 2 diabetes mellitus, and metabolic syndrome.
In animal studies, low levels of magnesium were associated with a myriad of problems, including hypomagnesemia.
The upper level for magnesium intake (meaning that you should not intake any more than this amount to be deemed “safe”) is 250-350 mg/day.
With that being said, there is little to no prevalence of magnesium intoxication from food intake and the upper level was determined via supplementation.
Magnesium is a mineral found in your tap water you do not need to worry about.
Calcium is known to have many positive effects on the body.
It may block the absorption of some heavy metals, increase bone density, and may even prevent some cancers.
It is recommended by the World Health Organization to have 20-30 mg/L of Calcium in drinking supplies for optimal health.
Calcium in tap water, like magnesium, is also a mineral that you should not worry about.
According to the Environmental Protection Division, the drinking water guidelines for zinc are 5 g/liter.
On average, the zinc found in our water supply meets these guidelines.
However, this varies city by city.
The zinc content, in some areas, was shown to be as high as 75 grams per liter, which can be very dangerous.
Possible negative effects of zinc intoxication include anemia, damage to the pancreas, and decreased levels of HDL cholesterol.
Studies conducted on rats have caused infertility, anemia, and kidney and pancreas damage.
Low levels of zinc also cause many problems including decreased taste and smell sensation, decreased immune function, slow healing of wounds, and skin sores, to name a few.
As long as zinc levels are within the 5 grams per liter range, there should not be a problem, but if the zinc levels are higher, many negative health implications may occur.
High levels of sodium intake are correlated with high blood pressure.
According to the Environmental Protection Agency, 20 mg/liter or less is recommended as “safe” for sodium intake.
According to a study conducted by the USDA, the average sodium content in tap water is 38 mg/liter—the highest being 391 mg/liter.
This has the potential to be dangerous, especially if you have high blood pressure as is.
These dangers were shown in an interesting study conducted by the American Heart Association.
In the study, two individuals had near-fatal effects after consuming tap water with high sodium levels.
With that being said, sodium has many benefits.
It plays an important role in maintaining an electrolyte balance.
However, our diets are typically high in sodium, so it is unnecessary for it to be consumed through tap water.
The EPA guidelines for copper in water is 1.3 mg/ liter.
Short term exposure to excess amounts of copper may lead to gastrointestinal distress while long-term exposure may lead to liver or kidney damage .
A study from 2009 showed a correlation between copper intake from sources like tap water to higher likelihood of getting Alzheimer’s Disease.
Ideally, copper should be avoided.
However, not all water filters are optimal for water filtration.
The three types of filters that can remove harmful substances, such as fluoride, include reverse osmosis, deionizers, and activated alumina.
If you buy water bottles, make sure that the filtration process includes one of those three types.
Another great option is water distillation. These can be purchased for your house in both small and large sizing options.
Water filters I don’t recommend include Brita, Pur, and most other filters that aren’t the ones listed above.