Is hard water healthier?
- Published: September 11, 2014
Allen Hunt has known since the 1970s that it is probably better to have calcium than sodium in his drinking water. After all, calcium is a vital nutrient many of us don’t get enough of, while Americans are said to already consume too much salt.
Today, for health reasons, Hunt makes sure he drinks the naturally hard, mineral-rich Yellow Springs water directly from the tap rather than the water that first passes through his home water softener, which adds sodium.
But he is concerned that if the Village decides to centrally soften its water, he will no longer have the choice to consume Yellow Springs’ harder water. Even if the municipal process softens the water without adding salt, could it be less healthy for local residents?
Decades after Hunt first learned that those who drink hard water had a lowered risk for dying from heart disease, his recent review of the literature suggests that magnesium may actually play the more significant role in cutting the risk of mortality from cardiovascular problems like heart disease, hypertension and stroke. Together, calcium and magnesium are the minerals that make local water “hard.” The majority of Americans are also deficient in them.
Hunt, a former program director in hydrologic sciences in the Geosciences Directorate of the National Science Foundation and a professor of physics and earth and environmental sciences at Wright State University, said he knows there is some ambiguity in the science, but is still convinced hard water is healthier.
Since Village Council will soon decide whether to centrally soften local water at its new or rehabilitated water plant, the issue has become somewhat pressing. Ultimately, for Hunt, it is a matter of choice.
“When I read that Yellow Springs was considering taking away our individual choice by selecting a pre-softened water treatment, I became concerned that my health could be compromised,” Hunt said last week.
Yellow Springs residents battle the hard water delivered to their tap every day. Two-thirds, according to a 2011 News survey, fight it with a water softener they must maintain by constantly adding salt. When not treated with a home softener, local water can clog pipes, cake in hot water heaters, dishwashers, washing machines, cloud dishes and form scum on bathtubs and showers.
High levels of dissolved calcium and magnesium from underground limestone and dolomite formations are the culprits behind local water hardness. But could these minerals also be good for our health?
To answer this question, Council has asked a consultant to investigate the health impacts of hard water and water softened through various methods. Along with Council members, Village Manager Patti Bates has said that health considerations will figure into her recommendation, in addition to the impact of hard and soft water on municipal infrastructure and the financial impact on local homes and businesses.
Could hard water be worse for our health? Council member Lori Askeland, citing research about the potentially corrosive nature of hard water, said Council is “taking the question of hard vs. soft water very seriously.”
“Very hard water, such as Yellow Springs naturally has, is corrosive, which can release heavy metals from pipes and solder into people’s drinking water,” she said.
A Council decision is expected in September or October, Bates said.
Hard, soft water: what we drink
According to the U.S. Geological Survey, 85 percent of the country has hard water at its taps. But Yellow Springs water may be among the hardest water in the country. Locally, water hardness is measured at 471 milligrams per liter, twice as high as the U.S. average and more than twice what the USGS considers “very hard” (180 mg/l).
While there are no legal standards for hardness in water, the Ohio Environmental Protection Agency maintains that hard water is not harmful to health while recommending water supplies stay between 120 and 180 mg/l of hardness, which is in the category of “hard.” The Ohio EPA also recommends that water not be too soft and should be above 80 mg/l so it doesn’t corrode pipes and leach lead, copper or other harmful elements into drinking water (other research shows that water that is too hard also corrodes pipes due to its alkalinity and lower pH).
Yellow Springs water is hard because it comes from groundwater — surface water is naturally softer. As naturally-acidic rainwater travels through limestone and dolomite bedrock and gravel deposits it dissolves calcium, magnesium and other minerals like iron and manganese in the rock. Small amounts of other minerals like zinc and arsenic can also dissolve into the water if present in the rocks. The municipal water treatment plant currently removes only iron and arsenic before delivering water to local residences and businesses.
According to a Village water and wastewater treatment superintendent Joe Bates, Yellow Springs water has 41 mg/l of dissolved magnesium and 120 mg/l of dissolved calcium. As local geologist Peter Townsend explained, local water can’t get much harder.
“Our water is about at the saturation limit,” Townsend said.
The minerals dissolved in local water then precipitate out when heated. For example, when water is boiled in a pot, a mineral deposit of calcium carbonate, or limestone, lines the bottom, Townsend explained. Limescale can build up on heating elements in hot water heaters, dishwashers, coffee makers and other appliances and on hot water pipes.
As a result, many villagers use water softeners that replace calcium and magnesium ions with sodium ions, in the process adding some sodium to the water. Concerned about the added salt in their drinking water, some villagers like Hunt have diverted tap water to their sinks or refrigerators, bypassing water softeners. Others keep an outside tap of hard water for watering plants.
The harder the water, the more sodium water softeners need to add. Using a calculation of how much sodium from the Water Quality Association, an industry group, two liters of completely softened Yellow Springs drinking water may contain 440 milligrams of sodium, about 30 percent of the amount of sodium the American Heart Association recommends that Americans consume each day.
Local retired physician Carl Hyde is another villager who chooses to drink hard water rather than softened water because of concerns that the extra sodium in his diet might lead to high blood pressure. When he built his house in 1989 a separate pipe was installed to divert tap water directly to the kitchen.
It’s unclear how many villagers drink water that is softened and how many drink hard water. A 2011 News survey of 235 municipal water customers (10 percent of Yellow Springs customers), revealed some data about local water-drinking habits.
For example, 80 percent of villagers said they mostly use tap water — the rest largely drink bottled or delivered water, which, if distilled, would contain hardly any calcium and magnesium. In addition, about 8 percent of those who drank tap water reported systems like reverse osmosis and distillation, which would remove calcium, magnesium, and sodium as well as most other ions in the water. About 30 percent use whole house filters, which remove only particulates but not calcium, magnesium or sodium. Many more villagers use faucet and jug carbon filters, which take out the chlorine but don’t remove calcium and magnesium or sodium. About two-thirds reported using a water softener, but it is unknown how many use softened water to drink. Older homes may not have water pipes that bypass a central water softener, so some villagers may not have a choice.
Hard water and heart health
What kind of water should Yellow Springers drink? Is drinking softened water actually bad for our health? And can drinking water with high levels of calcium and magnesium minerals significantly improve our health?
Numerous epidemiological studies dating from the 1950s have linked hard water with lower heart disease and stroke risks. Today’s researchers call it the “hard water cardiovascular disease benefits hypothesis.” Separate research has shown that calcium and magnesium are important minerals for body function and that deficiencies of the minerals can cause health problems.
For example, calcium, which is largely stored in the bones and teeth, is required for vascular contraction, muscle function, nerve transmission, intracellular signaling and hormonal secretion, according to the National Institutes of Health. Not getting enough calcium in one’s diet can cause calcium to leach from the bones and lead to osteoporosis and increased risk of fracture, a NIH website adds.
Magnesium, meanwhile, is vital to more than 300 enzyme systems that regulate biochemical reactions while it also plays a role in cell membrane transport, which is important to nerve impulse conduction, muscle contraction and normal heart rhythm, according to the NIH. The website adds that a deficiency in magnesium could lead to problems such as hypertension and cardiovascular disease, type 2 diabetes, osteoporosis, and migraine headaches.
While food is the major source of calcium and magnesium, drinking the minerals in water can supplement one’s diet, according to the NIH. For example, consuming two liters of Yellow Springs water would comprise about one-quarter of the daily recommended value of around 1,000 milligrams per day of calcium (an amount that varies by age and gender). And with an adult recommended daily value of 400 mg of magnesium per day, consuming two liters of Yellow Springs water would account for 20 percent of the daily value.
Studies show Americans aren’t getting enough of these vital minerals. About two-thirds of Americans don’t consume the recommended amounts of magnesium through their diets, according to a 2005 NIH-sponsored study. A CDC survey of 9,000 Americans between 2003 and 2006 showed that a whopping 85-90 percent of older Americans (over 71 years old) aren’t getting enough calcium.
As a matter of public health, why hasn’t the U.S. government encouraged drinking water rich in these minerals? Afterall, cardiovascular disease is the leading cause of death today in the U.S. and the industrialized world.
So far the World Health Organization has not recommended a minimum or optimal level of magnesium or calcium in drinking water and the U.S. Safe Drinking Water Act has not been amended to regulate the amount of calcium and magnesium in drinking water. One reason is that at least in the U.S., the regulatory focus has been more on reducing potentially-harmful contaminants in drinking water than increasing potentially-healthful minerals (with the exception of fluoride). Another is that most studies that demonstrate the protective benefits of hard water are epidemiological in nature and do not prove causality.
Experts do seem to agree that studies show drinking water with higher magnesium leads to a lower risk for cardiovascular mortality. The evidence for the benefits of calcium and hard water in general are less clear, they say. That was the conclusion of the World Health Organization in its 2009 report, “Calcium and Magnesium: Drinking Water Significance,” as well as the consensus of participants at a 2006 conference in Baltimore, Md., “Health Aspects of Calcium and Magnesium in Drinking Water.” A 2008 meta-analysis of 2,900 epidemiological studies came to the same conclusions.
Joseph Cotruvo, the manager of the Baltimore symposium in his article “Health Aspects of Calcium and Magnesium in Drinking Water,” writes that studies in Taiwan provide some of the strongest epidemiological evidence in favor of the water magnesium beneficial effect. According to local geologist Townsend, Taiwan may be the best country to look at for epidemiological studies as the government has long kept meticulous records of each place its citizens live and for how long (historically in the U.S., only births and deaths were recorded).
The Taiwan research, done primarily by researchers Chun-Yuh Yang, Hui-Fen Chiu, showed that higher magnesium intake in drinking water is associated with a decreased risk of hypertension and stroke. The researchers also found that higher calcium in drinking water reduces risks of heart attack and colon and stomach cancer and that harder water in general reduces the risk of throat cancer, conclusions that some organizations like the WHO don’t find convincing.
How much magnesium and calcium should drinking water contain? Cortruvo wrote that magnesium benefits appeared to level off at near 10 mg/l in five studies, a level far below the 41 mg/l currently in Yellow Springs water. Dr. Frantisek Kozisek of the National Institute of Public Health in the Czech Republic crafted drinking water hardness guidelines for that country based upon his review of the research. For magnesium the federal recommendation is a minimum of 10 mg/l and, optimally, 20-30 mg/l. For calcium, there should be at least 20 mg/l and an optimum of about 50 mg/l (Yellow Springs has 120 mg/l of calcium). The WHO has not updated its guidelines to recommend either minimum or optimum levels.
Hard water and corrosion
While the heart benefits of drinking water with dissolved magnesium appears to be clear, other questions about hard water remain. There is some indication that hard water could be worse for our health because it corrodes heavy metals from pipes during delivery. According to Michael Schock, a Cincinnati-based chemist in the U.S. EPA’s Water Supply & Water Resources Division, the same underground factors that give rise to hard water increase its alkalinity and causes pipes to leach the metals. Locally, treated water has an alkalinity of 368 mg/l, measured as calcium carbonate equivalent, according to Joe Bates.
Schock explained that it’s hard water’s high levels of bicarbonate, which is dissolved along with calcium and magnesium, that can corrode heavy metals from pipes for decades. Homeowners, meanwhile, can’t taste or see the difference in their water, he said.
According to a U.S. EPA website, exposure to lead through drinking water can delay the physical and mental development of children and cause high blood pressure and kidney problems in adults. Homes built before 1986 are more likely to contain lead pipes or copper pipes with lead solder, it added. Longterm exposure to copper, also widely used in household plumbing, can lead to liver or kidney damage, according to the EPA. Village distribution pipes are mostly made from cement-lined ductile iron and older unlined cast iron, according to Joe Bates, with some galvanized steel and PVC pipes. Most piping from street mains to households are copper, he added.
Naturally soft water is also corrosive, while softening water through ion exchange doesn’t change the chemical properties that make hard water corrosive, according to Schock. But when water is softened through a lime process (one of the options Yellow Springs is considering), the bicarbonate is reduced, and as long as the pH levels are kept up, copper, lead, iron and even cement linings won’t be corroded and leached into water, Schock said. In addition, lime softened water doesn’t need as much chlorine disinfection as hard water. Schock’s opinion is that softened water may be preferable for health.
“In summary there may not be as much hardness and magnesium as would be optimum for the cardiovascular system, but from a water quality, corrosion and infrastructure standpoint, the lime-softened [water] would be better,” he said.
Most studies on hard water and health compare the health of those who drink water that is naturally hard with those who drink naturally soft water. What if Yellow Springs’ naturally hard water was then softened? Would it retain some of its health benefits or cause less corrsion? Naturally soft water and softened water have vastly different properties, including different levels of alkalinity, pH and dissolved solids.
Geologist Townsend cautioned that since local water is vastly harder than any that has been studied systematically over the last few decades, it’s difficult to know exactly how beneficial local hard water could be. However, with such high levels, he said he believes that it is likely keeping villagers healthy.
“The benefits to the cardiovascular system are huge to drinking our water,” Townsend said. “To get as much as we now drink you’d have to up your caloric intake hugely.”
Visit ysnews.com for more information, including an expert opinion from Schock on hard water pipe leaching in Yellow Springs.