Water softeners can seriously harm health – by promoting cardiovascular disease – and the environment. The risk concerns the ion exchange systems installed everywhere – houses and offices, bars and restaurants, hotels – to remove limescale. An in-depth study.
The ‘limestone problem’
Almost all drinking water in Italy is characterized by a high ‘hardness’. That is to say the presence of significant quantities of mineral substances, particularly ions of calcium and magnesium. And the combination of these two ions generates limescale deposits when the water is heated above 40 °C.
Limescale buildup is a problem for the proper functioning of pipes and appliances in contact with hot water, boilers and water heaters (in primis). This tends to cause malfunctions and a reduction in the energy efficiency of the appliances, which require periodic maintenance interventions.
The use of softeners is undoubtedly useful in the treatment of water for technical use (e.g., heating systems, professional coffee machines, dry cleaners). And yet it can pose serious health risks, where the water is instead intended for human consumption.
Water softeners with ion exchange and demineralization
The ion exchange softeners are the most common systems in domestic and professional areas. These systems consist of a container for the resins, one for the salt – which is used to regenerate the resins – and an electronic device. Which starts (with a frequency that generally does not exceed 4 days) the regeneration process of the resins, otherwise subject to bacterial proliferation.
Limestone formation is inhibited through ion exchange. The calcium (Ca) and magnesium (Mg) ions are in fact retained in the resins and replaced by the release of sodium ions into the water, which do not produce encrustations. A saving exchange for the serpentines of the boiler and boiler exchangers, which can however cause various damage to health and the environment.
Ion exchange and demineralization, the risks
The ministerial guidelines on drinking water softening systems call for attention ‘to the potential risks of excessive demineralization of water and consequent lower intake of micronutrients and mineral salts for the consumer that could be associated with certain treatments’. (1)
In fact, it is precisely calcium and magnesium – the main determinants of the ‘hardness’ of drinking water – that play a crucial role in the diet. And water represents a primary source of it, particularly for lactose intolerant individuals and vegans.
‘Users of these devices must be informed of the changes in mineral composition caused by the treatments and of the possible consequences on the total nutrient intake ‘ (World Health Organization, WHO. See footnote 2).
In addition to the risk of mineral depletion, waters treated with an ion exchange softener are enriched in sodium (an ion added to annihilate calcium and magnesium). An element known to be harmful to the cardiovascular system.
Precisely for these reasons the standards that set the drinking water parameters establish minimum hardness thresholds and maximum sodium concentration thresholds. Without limiting the presence of mineral salts, as fundamental trace elements that the human body does not produce, of which water is the most precious source of daily intake. (3)
The benefits of calcium and magnesium
The health effects of limestone precursors are beneficial to the general population. In fact, minerals dissolved in drinking water are essential elements to the body.
‘The Calcium ion is the second most common messenger in eukaryotic cells. In fact, it has been seen that a great variety of stimuli, ranging from growth factors to neurotransmitters, are transmitted inside the cell through variations in the calcium concentration inside the cells. (…) Calcium therefore plays a role of fundamental importance in all biological systems’, (prof. Paolo Pinton, University of Ferrara. Extract from the report given at the ‘Labirinto D’Acque’ Conference on 24.03.2018).
On the cardio-circulatory system moreover, the two minerals that make water hard have had a protective effect known since the late 1950s. Hundreds of epidemiological studies, conducted ‘in different periods, geographical areas and populations have reaffirmed the existence of a protective effect of the dissolved calcium and magnesium contents against the occurrence of CVDs’. (4)
The negative impact on the environment
Another problem caused by ion exchange softeners is the environmental impact. The treatment processes in fact return acidic water, with a high concentration of chlorides, highly corrosive and polluting.
For this in many countries water softeners are only permitted for very specific technical uses and in any case for the treatment of water not intended for human consumption. In many states of the US federation, where this technology has had the greatest development, such systems have been banned for some years due to their devastating impact on the environment.
Provisional conclusions and new horizons
The water is our body’s primary nutrient, and the minerals it contains are critical to our health. Never before has our body needed trace elements that it is unable to produce and they play vital roles. Those who have equipped their homes or offices with ion exchange softeners should therefore have them checked periodically to ensure the safety of water for human consumption.
The new horizons consist of new ‘physical’ water treatment systems, which can reduce the formation of limestone without however altering the chemical composition of the water. These systems – which consist of magnetic or ultrasonic equipment – break up the molecular bonds of the minerals and prevent the formation of the calcite crystal when the water reaches 40 degrees. The water thus treated forms instead aragonite crystals, which:
– are harmless, for plumbing as well as for health, and
– remain in suspension in the water, thanks to their very small size, without being able to aggregate or give rise to encrustations.
Marta Strinati and Dario Dongo
Footnotes
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Ministerial Decree. (2012, February 7). Guidelines on water treatment devices intended for human consumption pursuant to ministerial decree February 7, 2012, n. 25.
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See note 1.
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Italian Republic. (2001). Legislative Decree 31/2001 and subsequent amendments concerning the quality of water intended for human consumption. Official Journal of the Italian Republic.
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Ottaviani, M., Achene, L., Ferretti, E., & Lucentini, L. (2007). The hardness of water intended for human consumption: effects on human health. Newsletter of the Higher Institute of Health, 20(3), March
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
