Mineral water composition. Discussion of the optimal mineral composition of drinking water. The benefits and harms of mineral water

The most valuable information about the effects of low calcium concentrations in drinking water on an entire population of people came from studies conducted in the Soviet city of Shevchenko (now Aktau, Kazakhstan), where the city water supply used desalination plants (water source - the Caspian Sea). Decreased alkaline phosphatase activity, decreased plasma calcium and phosphorus concentrations, and increased decalcification were observed in the local population bone tissue. These changes were most noticeable in women, especially pregnant women, and depended on the length of residence in Shevchenko. The need for calcium in drinking water is also confirmed in a one-year experiment on rats that were provided with a completely adequate diet in terms of nutrients and salts, but were fed distilled water to which 400 mg/l of calcium-free salts and one of these calcium concentrations were added: 5 mg/l, 25 mg/l or 50 mg/l. Rats fed water with 5 mg/l calcium showed a decrease in hormone functionality thyroid gland and other related functions in comparison with the rest of the animals participating in the experiment.

It is believed that overall change composition drinking water affects human health after many years, and a decrease in the concentration of calcium and magnesium in drinking water affects well-being almost instantly. Thus, residents of the Czech Republic and Slovakia in 2000-2002 began to actively use reverse osmosis systems in their apartments for the purification of city water. Within a few weeks or months, local doctors were inundated with complaints indicating acute magnesium (and possibly calcium) deficiency: cardiovascular disorders, fatigue, weakness and muscle cramps.

3. The risk of a deficiency of vital substances and microelements when drinking low-mineralized water.

Although drinking water, with rare exceptions, is not the main source of vital elements for humans, it can make a significant contribution to their intake for several reasons. First, food of many modern people- rather poor source minerals and microelements. In the case of a borderline deficiency of any element, even its relatively low content in consumed drinking water can play a corresponding protective role. This is due to the fact that the elements are usually present in water as free ions and are therefore more easily absorbed from water compared to food, where they are mainly found in complex molecules.

Animal studies also illustrate the importance of micro-sufficiency of certain elements present in water. Thus, according to V. A. Kondratyuk, a slight change in the concentration of microelements in drinking water dramatically affects their content in muscle tissue. These results were obtained in a 6-month experiment in which rats were randomized into 4 groups. The first group was given tap water, the second - low-mineralized water, the third - low-mineralized water with the addition of iodide, cobalt, copper, manganese, molybdenum, zinc and fluoride. The last group received low-mineralized water with the addition of the same elements, but ten times more high concentration. It was found that low-mineralized water affects the process of hematopoiesis. In animals that received demineralized water, the average hemoglobin content in erythrocytes was 19% lower compared to rats that were given tap water. The differences in hemoglobin content were even higher compared to animals receiving mineral water.

Recent epidemiological studies in Russia, conducted among population groups living in areas with varying salinity water, indicate that low-mineralized drinking water can lead to hypertension and coronary heart disease, stomach ulcers and duodenum, chronic gastritis, goiter, pregnancy complications and a number of complications in newborns and infants, including jaundice, anemia, fractures and growth disorders. However, the researchers note that it remains unclear to them whether it is drinking water that has such an effect on health, or whether it’s all about the general environmental situation in the country.

Answering this question, G.F. Lutai conducted a large cohort epidemiological study in the Ust-Ilimsk district of the Irkutsk region in Russia. The study focused on the morbidity and physical development of 7658 adults, 562 children and 1582 pregnant women and their newborns in two areas supplied with water differing in total salinity. The water in one of these areas had a total salt content of 134 mg/l, of which calcium 18.7 mg/l, magnesium 4.9 mg/l, bicarbonates 86.4 mg/l. In another area, the total mineralization of water was 385 mg/l, of which calcium 29.5 mg/l, magnesium 8.3 mg/l and bicarbonates 243.7 mg/l. The content of sulfates, chlorides, sodium, potassium, copper, zinc, manganese and molybdenum in water was also determined. The population of these two areas did not differ from each other in social and environmental conditions, time of residence in the respective areas, eating habits. Among the population of the area with less mineralized water, more high performance incidence of goiter, hypertension, coronary disease heart, stomach and duodenal ulcers, chronic gastritis, cholecystitis and nephritis. Children living in this area showed slower physical development and exhibited growth abnormalities. Pregnant women were more likely to suffer from edema and anemia. Newborns in this area were more susceptible to disease. The lowest incidence was observed in areas with hydrocarbonate water, having a total mineralization of about 400 mg/l and containing 30-90 mg/l calcium and 17-35 mg/l magnesium. The author came to the conclusion that such water can be considered physiologically optimal.

4. Washing useful substances from food prepared in low-mineralized water.

It has been found that when softened water is used for cooking, significant loss food products (meat, vegetables, cereals) micro- and macroelements. Up to 60% of magnesium and calcium, 66% of copper, 70% of manganese, 86% of cobalt are washed out of products. On the other hand, when hard water is used for cooking, the loss of these elements is reduced.

Since most nutrients are supplied to the body through food, the use of low-mineralized water for cooking and processing food products can lead to a noticeable deficiency of some important micro- and macroelements. Most people's current menu usually doesn't contain everything necessary elements in sufficient quantities, and therefore any factor that leads to the loss of essential minerals and nutrients during the cooking process further aggravates the situation.

5. Possible increase entry of toxic substances into the body.

Low-mineralized, and especially demineralized water is extremely aggressive and can leach heavy metals and some organic substances from materials with which it comes into contact (pipes, fittings, storage containers). In addition, calcium and magnesium contained in water have to some extent an antitoxic effect. Their absence in drinking water, which also got into your tin mug through copper pipes, can easily lead to heavy metal poisoning.

Among eight cases of intoxication drinking water, registered in the USA in 1993-1994, there were three cases of lead poisoning in infants, in whose blood lead levels were found to be 1.5, 3.7 and 4.2 times higher, respectively. In all three cases, lead leached from lead-soldered seams in storage tanks for reverse osmosis drinking water used for baby formula.

It is known that calcium and, to a lesser extent, magnesium have antitoxic activity. They prevent the absorption of ions into the blood from the intestines heavy metals, such as lead and cadmium, by competing for binding sites. Although this protective effect is limited, it cannot be dismissed. At the same time, other toxic substances may enter into chemical reaction with calcium ions, forming insoluble compounds and thus losing their toxic effect. Populations in areas supplied with low-salinity water may be at increased risk of toxic poisoning compared to those in areas where regular hard water is used.

6. Possible bacterial contamination of low-mineralized water.

This point in the original article is a little far-fetched, but still. Any water is susceptible to bacterial contamination, which is why pipelines contain a minimum residual concentration of disinfectants - for example, chlorine. It is known that reverse osmosis membranes are capable of removing almost all known bacteria from water. However, reverse osmosis water also needs to be disinfected and a residual concentration of the disinfectant must be kept in it to avoid secondary contamination. A case in point is the outbreak of typhoid fever caused by reverse osmosis treated water in Saudi Arabia in 1992. They decided to abandon the chlorination of reverse osmosis water, because, in theory, it was obviously sterilized by reverse osmosis. Czech national institute Public Health in Prague tested products intended to come into contact with drinking water and found, for example, that the pressure tanks of household reverse osmosis units were susceptible to bacterial growth.

Drinking water with low mineralization leads to the leaching of salts from the body. Because the side effects such as violation water-salt metabolism, were observed not only in experiments with completely demineralized water, but also when using low-mineralized water with a total salt content in the range from 50 to 75 mg/l, Yu. A. Rakhmanin’s group in its report to WHO recommended setting a lower limit for the total mineralization of drinking water at the level of 100 mg/l. The optimal level of salt content of drinking water, according to these recommendations, should be about 200-400 mg/l for chloride-sulfate waters and 250-500 mg/l for hydrocarbonate waters. The recommendations were based on extensive experimental studies conducted on rats, dogs and human volunteers. Moscow tap water was used in the experiments; desalinated water containing approximately 10 mg/l of salts; laboratory prepared water containing 50, 100, 250, 300, 500, 750, 1000 and 1500 mg/l of dissolved salts with the following ionic composition:

• among all anions there are 40% chlorides, 32% bicarbonate anions, 28% sulfates;
• among all cations there is sodium 50%, calcium 38%, magnesium 12%.

In addition to the level of total mineralization, this report justifies the minimum calcium content in drinking water - not lower than 30 mg/l. This requirement was introduced after studying the critical effects resulting from hormonal changes in the metabolism of calcium and phosphorus and a decrease in bone mineralization when drinking calcium-deprived water. The report also recommends maintaining bicarbonate anion content at 30 mg/L to maintain acceptable sensory characteristics, reduce corrosivity, and establish an equilibrium concentration for the recommended minimum calcium concentration.

Later research led to the emergence of refined requirements. Thus, one of them studied the effect of drinking water containing different concentrations of hardness salts on the health of women aged 20 to 49 years in four cities of Southern Siberia. Water in city A had the lowest content of these elements (3.0 mg/l calcium and 2.4 mg/l magnesium). The water in city B was harder (18.0 mg/l calcium and 5.0 mg/l magnesium). The highest hardness was observed in cities C (22.0 mg/l calcium and 11.3 mg/l magnesium) and D (45.0 mg/l calcium and 26.2 mg/l magnesium). Women living in cities A and B were more likely to be diagnosed with the disease of cardio-vascular system(data obtained using ECG), higher blood pressure, somatoform autonomic dysfunctions, headache, dizziness and osteoporosis (data obtained using X-ray absorptiometry) compared with those in cities C and D. These results indicate that the minimum magnesium content in drinking water should be 10 mg/l, and the minimum calcium content can be reduced to 20 mg/l l (compared to WHO recommendations 1980).

Based on currently available data, various researchers have ultimately come to the following recommendations regarding the optimal hardness of drinking water:

A. magnesium - at least 10 mg/l, optimally about 20-30 mg/l;
b. calcium - at least 20 mg/l, optimally 40-80 mg/l;
V. their sum (total hardness) is 4-8 mEq/l.

At the same time, magnesium is limited from below in its effect on the cardiovascular system, and calcium is limited as a component of bones and teeth. The upper limit of the optimal hardness range was set based on concerns about the possible influence of hard water on the occurrence of urolithiasis.

The effect of hard water on the formation of kidney stones

Based on their chemical composition, there are several types of urinary stones, however, due to the hardness of the water, they are mainly of interest to phosphates and oxalates. In case of disturbance of phosphorus-calcium metabolism or in case of hypervitaminosis of vitamin D, phosphate stones. An increased content of oxalic acid salts - oxalates - in food can lead to the appearance of oxalate stones. Both calcium oxalate and calcium phosphate are insoluble in water. By the way, there are a lot of oxalates not only in sorrel, but also in chicory, parsley, and beets. Oxalates are also synthesized by the body.

The effect of water hardness on the formation of urinary stones is difficult to determine. Most studies assessing the effect of water hardness on the occurrence and development of urolithiasis use medical data. inpatient institutions. In this sense, the study conducted by Schwartz et al. , differs significantly in that all data were collected in an outpatient setting, with patients remaining in their natural environment and going about their normal activities. This work presents the largest cohort of patients to date, allowing us to evaluate the effect of water hardness on various components of urine.

Scientists have processed extensive material. Protection Agency environment The United States (EPA) provided information on the chemical composition of drinking water in the United States with geographic reference. This information was combined with a national database of outpatients suffering from urolithiasis(it contains the patient's zip code, so geo-referencing was possible). In this way, 3270 were identified outpatient with calcium stones.

In the minds of most people, increased water hardness is synonymous with increased risk development of urolithiasis (kidney stones - special case urolithiasis). The content of minerals, and especially calcium, in drinking water appears to be perceived by many people as a health threat.

Despite these common concerns about water hardness, no research supports the idea that drinking hard water increases the risk of developing urinary stones.

Sierakowski et al. studied 2,302 medical records from inpatient hospitals throughout the United States and found that patients who lived in areas with hard water had a lower risk of developing urolithiasis. Similarly, in the cited work it was found that the hardness of drinking water is inversely proportional to the incidence of urolithiasis.

In this study, the incidence of urolithiasis was slightly higher in patients living in areas with softer water, which is consistent with data from other authors, but contrary to public perception. It is known that in some cases, such as those suffering from hypercalciuria, increased oral calcium intake may aggravate the formation urinary stones. In patients with hyperoxaluric calcium nephrolithiasis, in contrast, increased oral calcium supplementation can successfully inhibit stone formation by binding oxalic acid salts to calcium in the intestine and thus limiting the entry of oxalates into the urinary system. Calcium intake from drinking water may potentially have an inhibitory effect on calcium urinary stone formation in some patients and promote stone formation in others. This theory was tested in a study by Curhan et al., which assessed the effect of calcium intake in 505 patients with recurrent stone formation. After 4 years of observation, the group of patients taking calcium had the least number of episodes of urinary stones. The researchers concluded that high dietary calcium intake reduces the risk of symptomatic urolithiasis.

Despite public concern about the potential lithogenesis of hard tap water, existing scientific evidence suggests that there is no relationship between water hardness and the prevalence of urinary stones. There appears to be a correlation between water hardness and urinary calcium, citrate and magnesium levels, but the significance of this is unknown.

By the way, the author makes an interesting comparison: consuming one glass of milk can be equivalent to two liters of tap water in terms of calcium content. So, according to the Ministry Agriculture USA (USDA), 100 g of milk contains 125 mg of calcium. The same amount of city water contains only about 4-10 mg of calcium.

Conclusion

Drinking water produced by industrial desalination plants is usually remineralized, but reverse osmosis water is usually not mineralized at home. However, even with the mineralization of desalinated waters, their chemical composition may remain unsatisfactory from the point of view of the body's needs. Yes, calcium salts can be added to the water, but it will not contain other essential microelements- fluorine, potassium, iodine. In addition, desalinated water is mineralized more for technical reasons - to reduce its corrosiveness, and the importance of substances dissolved in water for human health is usually not thought about. None of the methods used for remineralizing desalinated water can be considered optimal, since only a very narrow set of salts is added to the water.

The effect of hard water on the formation of kidney stones has not been scientifically proven. There are concerns that increased consumption of oxalic acid salts or phosphates together with calcium may lead to crystallization of insoluble substances in the urinary system. calcium salts phosphoric or oxalic acids, however, the body of a healthy person, according to existing scientific data, is not subject to such a risk. Persons suffering from kidney disease, hypervitaminosis of vitamin D, disorders of phosphorus-calcium, oxalate, citrate metabolism or consuming significant amounts of oxalic acid salts may be at risk. It has been established, for example, that healthy body without any consequences for itself, it is able to process up to 50 mg of oxalates per 100 g of food, however, spinach alone contains oxalates 750 mg/100 g, so vegetarians may be at risk.

In general, demineralized water is no less harmful than waste water, and in the 21st century it is high time to move away from rationing water quality indicators only from above. Now you also need to install lower limits content of minerals in drinking water. Physiologically, only a narrow corridor of concentrations and composition of drinking water is optimal. The currently available information on this issue can be presented in the form of a table.

Table 1. Optimal mineralization of drinking water

From the history of the use of mineral waters to treat diseases

“Mineral waters of salt, ferruginous, sulfuric, iodide, carbonic acid, etc. There are as many ways to cure ailments as there are sand on bottom of the sea», – wrote a hundred years ago, M. Platen in his “Guide to living according to the laws of nature, to maintain health and to treat without the help of drugs.” The term “ mineral water" came into use in the 16th century, but in everyday life the word " water", and, just like in Ancient Rome « aquae", - in plural. Origin of the word " aquae" refers to the time when Thales of Miletus (c. 624 - c. 546 BC) - a Greek philosopher and mathematician from Miletus, trying to determine the basis of the material world, came to the conclusion that it was water. Word " aqua" - water, consists of two Greek words - "a" and "qua", the literal translation is from which (implies omnia constant- everything happened, everything is complete).

The first attempt to classify mineral waters by composition belongs to the Greek scientist Archigen (II century). He identified four classes of waters: aquae nitrose, aluminose, saline and sulfurose (alkaline, ferruginous, salty and sulphurous). L.A. Seneca identified sulfur, iron, and alum waters and believed that taste indicated their properties. Archigen recommended sulfur baths for gout, and for bladder diseases he prescribed drinking mineral waters up to 5 liters per day. He believed that it was enough to know the composition of water to prescribe it for treatment. It should be noted that the composition of the water at that time could not be known even approximately.

G. Fallopius, the author of one of the first manuals on mineral waters that have survived to our times, published after his death, speaks about the composition of mineral waters (“ De thermalibus aquis atque metallis", 1556). However, the composition of the waters of Italy, described by Fallopius, was far from true, since the science of the 16th century. many were not yet known chemical elements. A real breakthrough in the study of mineral waters occurred in the 18th century, after revolutionary discoveries in chemistry, which are mainly associated with the name of A. Lavoisier. The very concept of “mineral waters” (from Lat. minari- dig) was formed during the 19th-20th centuries, when the foundations of balneology (health resorts) and scientific basis use of groundwater for medical purposes.

The first resort in Russia was built by Decree of Peter the Great on the sources of ferruginous Martial waters. Peter I upon his return from Belgium, where he was successfully treated with the waters of the Spa resort. In honor of Russian Emperor A drinking pavilion was built at the resort - “Pouhon Pierre Le Grand”. Peter I called the waters of the Belgian resort a source of salvation, and upon returning to Russia he issued a decree to look for key waters in Russia that can be used to treat diseases. The first Russian resort was built in Karelia on the Olonets waters, called Marcial. Marcial waters exceed all known ferrous sources in the world in terms of the content of divalent ferrous iron - up to 100 mg/l. The iron content in the waters of the Belgian ancestor of resorts – Spa, is only 21 mg/l (ferruginous waters – Fe 10 mg/l).

The first cadastre of mineral waters in Russia was compiled by scientists of the Mineralogical Society, created in 1817 in St. Petersburg. Among its founders were academician V.M. Severgin and Professor D.I. Sokolov. According to studies of numerous academic expeditions of the late 18th and early XIX centuries V.M. Severgin described the mineral springs and lakes of Russia, classified them according to a set of characteristics and compiled instructions for their research. The results of the research were summarized in the book “A Method for Testing Mineral Waters, Compiled from the Latest Observations on the Subject,” published in St. Petersburg in 1800. In 1825, the work of the Russian chemist G.I. Hess "Study chemical composition And healing effect Mineral Waters of Russia", which became the basis of his dissertation for the degree of Doctor of Medicine.

An important role in the study of medicinal mineral waters was played by the founding in 1863 of the Russian Balneological Society in the Caucasus on the initiative of the director of the Caucasian Mineral Waters resort management, Professor S.A. Smirnova. After 1917 (after the nationalization of resorts), the intensive development of balneology began. In 1921, the Balneological Institute was created in the Caucasian Mineral Waters (in , in 1922 - the Tomsk Balneophysiotherapeutic Institute, and in 1926 the Central Institute of Balneology and Physiotherapy was opened in Moscow.

Chemical composition of mineral waters

Mineral water– complex solutions in which substances are contained in the form of ions, undissociated molecules, gases, colloidal particles.

For a long time, balneologists could not come to a consensus on the chemical composition of many waters, since the anions and cations of mineral waters form very unstable compounds. As Ernst Rutherford said, “ions are cheerful little kids, you can almost see them with your own eyes.” Back in the 1860s. chemist O. Tan pointed out the incorrectness of the salt image of mineral waters, which is why Zheleznovodsk has long been considered a resort with an “unestablished reputation.” At first, the mineral waters of Zheleznovodsk were classified as alkali-ferrous, then they began to combine carbonates with alkalis, and sulfates with alkaline earths, calling these waters “alkali-ferrous (containing sodium carbonate and iron) with a predominance of gypsum (calcium sulfate) and soda (sodium bicarbonate ). Subsequently, the composition of waters began to be determined by the main ions. The unique Zheleznovodsk springs in composition belong to carbon dioxide, bicarbonate-sulfate, calcium-sodium, high-thermal waters, containing little sodium chloride, which eliminates the risk of irritation renal tissue when used for drinking purposes. Currently, Zheleznovodsk is considered one of the best “kidney” resorts. The mineral waters of this resort contain relatively little iron, up to 6 mg/l, i.e. less than in specific ferruginous waters, which must contain at least 10 mg/l.

In the German “Spa Book”, published in 1907, water analyzes mineral springs were first presented in the form of ionic tables. The same book about Austrian spas was published in 1914. This type of presentation of mineral waters is currently accepted in Europe. As an example, we give the ionic composition of the waters of one of the most popular springs of the French resort of Vichy, known since the times of the Roman Empire - Vichy Celestins (M - 3.325 g/l; pH - 6.8).

Criteria for classifying waters as “mineral”

Criteria for classifying waters as “mineral” vary to varying degrees among different researchers. They are all united by their origin: that is, mineral waters are waters extracted or brought to the surface from the bowels of the earth. At the state level, in a number of EU countries, certain criteria for classifying waters as mineral waters have been legislatively approved. National regulations regarding the criteria for mineral waters reflect the hydrogeochemical features of the territories that are inherent in each country.

In the regulations of a number of European countries and international recommendations - the Codex Alimentarius, Directives of the European Parliament and the European Council for EU member countries, the definition of “mineral waters” has acquired a broader content.

For example, " Codex Alimentarius" gives the following definition of natural mineral water: natural mineral water is water that clearly differs from ordinary drinking water because:

• it is characterized by its composition, including certain mineral salts, in a certain ratio, and the presence of certain elements in trace quantities or other components
• it is directly obtained from natural or drilled sources from underground aquifers, for which it is necessary to observe all precautions within the protection zone to avoid the entry of any contamination or external influence on the chemical and physical properties of mineral waters;
• it is characterized by the constancy of its composition and stability of flow rate, a certain temperature and corresponding cycles of minor natural fluctuations.

In Russia, the definition of V.V. Ivanov and G.A. Nevraev, given in the work “Classification of underground mineral waters” (1964).

Healing mineral waters are called natural waters, which contain in elevated concentrations certain mineral (less often organic) components and gases and (or) have some physical properties(radioactivity, environmental reaction, etc.), due to which these waters have an impact on the human body therapeutic effect to one degree or another, which differs from the action of “fresh” water.

Mineral drinking waters (in accordance with) include waters with a total mineralization of at least 1 g/l or with less mineralization, containing biologically active microcomponents in quantities not lower than balneological standards.

Mineral composition of drinking water

Water is suitable for drinking if its total mineralization does not exceed 1000 mg/l. Very low mineralization of water (up to 100 mg/l) also worsens its taste, and water devoid of salts - distilled - is harmful to human body, since its use disrupts digestion and the functioning of the glands internal secretion. In accordance with hygienic requirements for water quality, total mineralization should not exceed 1000 mg/l. In agreement with the sanitary and epidemiological authorities, for a water supply system supplying water without appropriate treatment (for example, from artesian wells), an increase in mineralization to 1500 mg/l is allowed.

They usually say: clean water is the key to health. There is a lot of tasty water in nature, but it is not and cannot be ideally pure. Water is one of the best solvents, so drops of rain or snow, before falling on the ground, are enriched with nitrogen, oxygen, carbon dioxide, dust and other components found in the atmosphere. Thus, in one of the cleanest areas, in the Yenisei sector of the Arctic, far from the Arctic Ocean, 1 liter of water obtained from snow contains an average of 93 mg of mineral salts , oxygen, sodium and sulfur . Even distilled water from pharmacies and laboratories is not perfectly pure. The famous scientist F. Kohlrausch distilled water 42 times in a special glass vessel under reduced pressure, but perfectly clean water never received due to the penetration of carbon dioxide, oxygen and nitrogen impurities from the air.

To date, it has been established that water with an increase in the content of chlorides and sulfates, in addition to bad taste, also acquires the ability to negatively affect the functions of the digestive system. Increased calcium content promotes stone formation in the kidneys and bladder. Latest Research showed that long-term drinking water of the chloride-sulfate class with mineralization increased to 3 g/l has a very negative effect on the course of pregnancy and childbirth, on the fetus and newborn, and on gynecological morbidity.

Comparative data on maximum permissible concentrations of mineral salts and some metals acting in different countries, are given in table. 5.6.

Table 5.6 - MPC of some chemical substances in drinking water, mg/l

The content of large amounts of soluble calcium and magnesium salts in drinking water not only negatively affects the taste, but also causes its hardness. Hard water is unfavorable in many respects: it makes it more difficult for vegetables and meat to boil, their nutritional value decreases, cleaning ability sharply deteriorates and soap consumption increases. Hard water forms scale, which damages kettles and boilers and clogs water pipes. According to the latest scientific data, drinking hard water contributes to the development of a number of diseases. Thus, with excess calcium and magnesium salts in drinking water, the colloid-crystalloid balance of urine is disturbed, which contributes to the occurrence of urolithiasis. In real living conditions Most often, urolithiasis is probably caused not by any one cause, but by several. However, the salt composition of drinking water is one of the factors contributing to the development of this disease. The positive role of hard drinking water is that there are fewer cases of heart attacks and attacks of hypertension.

The total liquid of water is determined by the sum of calcium ion concentrations (calcium liquid) and magnesium ions (magnesium water hardness). It consists of carbonate(temporary, eliminated by boiling) and non-carbonate(constant) water hardness. The first is caused by the presence of Ca and Mg hydrocarbonates in water, the second by the presence of sulfates, chlorides, nitrates, phosphates and silicates of these metals. When boiled for 1 hour, Ca and Mg bicarbonates decompose

and water hardness decreases. Therefore, the term “temporary hardness” is sometimes adopted, meaning the presence of bicarbonates removed from water when it is boiled. The remaining hardness of water after boiling is called constant rigidity.

In Ukraine and Russia, water hardness is expressed in moles per 1m3. The numerical value of hardness, expressed in mol/m 3 , is equal to the numerical value of hardness, expressed in mEq/l. One mole per m 3 corresponds to a mass concentration of equivalent calcium ions (1/2 Ca +2) 20.04 g/m 3 and magnesium ions (1/2 Mg +2) 12.15 g/m 3 . The total hardness of the liquid consists of calcium and magnesium hardness, i.e. total concentration in the form of Ca +2 and Mg +2 ions:

.

(5.1)

Hardness of water softened for feeding steam boilers high pressure, expressed in mcg-eq/l (1 mcg-eq = 0.001 mg-eq).

In other countries, water hardness is measured in degrees of hardness. Thus, in Germany, 10 hardness expresses the content of 0.01 g of CaO in 1 liter of water; in Great Britain, water hardness is measured in degrees of hardness, expressing the content of CaCO 3 in grains (1 grain = 0.0648 g) in 1 gallon (4.546 l) of water; in France, 1 0 hardness is equal to 1 g of CaCO 3 in 100,000 g of water. Comparative data on units of measurement of water hardness in different countries are given in table. 5.7.

Table 5.7 - Comparative data on water hardness units

The value of total hardness in drinking water should not exceed 7 mg. eq/l; only in some cases, in agreement with the Chief State Sanitary Doctor, a total water hardness of up to 10 mg- is allowed for a specific water supply system. eq/l

Water hardness varies widely. Water with a hardness of less than 4 mg-eq/l is considered soft, from 4 to 8 mg-eq/l – medium hard, from 8 to 12 mg-eq/l - hard and above 12 mg-eq/l - very hard. In surface water sources, where, as a rule, carbonate hardness predominates (up to 70% of the total), and magnesium hardness usually does not exceed 30% (less often 60% of the total: Donbass, Krivoy Rog), highest value Water hardness reaches its lowest point at the end of winter, during the flood period. In groundwater, water hardness is more constant and changes less throughout the year.

Rigidity sea ​​water: Black Sea – calcium 12 mg-eq/l, magnesium 53.5 mg-eq/l, total 65.5 mg-eq/l; oceans – calcium 22.5 mg-eq/l, magnesium 108 mg-eq/l, total 130.5 mg-eq/l.

Currently, a large amount of statistical material has shown the existence of a correlation between cardiovascular diseases and the hardness of drinking water: The softer the drinking water, the greater the likelihood of the population developing cardiovascular diseases. In particular, in the USA and Canada it has been established that among the population consuming soft drinking water containing less than 75 mg/l of calcium, mortality is 15...20% higher than among the population consuming hard water. For the UK this difference is 40%.

It should be noted that there is no generally accepted point of view on the mechanism of the impact of drinking water hardness on the activity of the cardiovascular system: different researchers assess the actions of this mechanism differently, and they also disagree on the degree of danger of soft drinking water for human health.

There are several groups of hypotheses that explain the mechanism of action of drinking water quality on the functions of the cardiovascular system of the human body.

According to first group of hypotheses, hard water has certain protective properties associated with the presence of magnesium and calcium cations in drinking water. According to this hypothesis, an increase in calcium content in water prevents the formation of cholesterol in the body, while magnesium prevents the accumulation of lipids in the arteries and also has anticoagulant properties, which helps reduce the likelihood of thrombosis.

Thus, an epidemiological survey of the population drinking water with low magnesium content (Ohio, USA) revealed a higher incidence of coronary disease, as well as cases of sudden death, compared to areas where the population drinks water with normal content. of this microelement. The magnesium content in the myocardium of people who died from heart attacks was reduced by 12...15%.

Data have been published showing that when water hardness is 7 mEq/L, an additional 27% of magnesium enters the body. The role of “water magnesium” is supported by its better absorption from water (up to 60%) compared to food (30%). Taking this into account, data on the role of magnesium in hard waters in reducing cardiovascular pathology acquire special significance.

Second group of hypotheses claims that hard water contains large quantity other elements (besides Mg and Ca) that perform protective functions. These elements include, first of all, lithium and vanadium, as well as manganese and chromium. Vanadium, according to some data, prevents the formation of cholesterol, lithium can help improve blood circulation in venous vessels hearts.

Third group of hypotheses indicates that soft water, due to its corrosive properties, contains a greater amount of metals that negatively affect the functioning of the cardiovascular system. Among these metals, researchers name cadmium, lead, copper and zinc. Cadmium and lead appear to increase blood pressure.

Mineral water is water saturated with minerals, depending on the different set of components contained and concentration, mineral waters are divided into different types.

Sulfate– acts as a choleretic and laxative. Recommended for use by people with liver problems, gall bladder, obesity and diabetes mellitus.

Chloride– has a beneficial effect on the functioning of the intestines, liver and bile ducts. It is strictly forbidden for people with.

Magnesium– help with stress, but are contraindicated for people who have frequent disorders stomach.

Ferrous, etc.

Depending on the gas composition of mineral water and the presence of certain components, mineral waters are divided into:

Carbon dioxide;

Hydrogen sulfide;

Nitrogen;

Silicon;

Bromide;

Iodide;

Ferrous;

Arsenic;

Radioactive;

The division of mineral water depending on its acidity or alkalinity; mineral water, compared according to the pH criterion, is divided into:

Acidic pH=3.5-6.8

Neutral pH=6.8-7.2

Alkaline pH=7.2-8

BOTTYLATION OF MINERAL WATER

To preserve the salt composition and medicinal properties Mineral water is poured into hermetically sealed containers, having previously been carbonated with carbon dioxide. Carbon dioxide does not allow salts to precipitate.

On the mineral water label you can usually see the chemical composition of the mineral water. However, it is quite difficult for a non-specialist to understand the composition of mineral water and for what medicinal purposes such water can be used.

Mineral water has both natural outlets to the surface and artificially created by man, i.e. wells. For bottling, only water from boreholes is used. This ensures the consistency of the chemical composition of mineral water. To protect the source from depletion or contamination, sanitary zones are established.

HEALING PROPERTIES OF MINERAL WATER

Start off treatment course mineral water is necessary only after a comprehensive examination by a doctor and receiving clear recommendations from him.

Sodium chloride waters are used for gastritis, which is characterized by low acidity gastric juice. These waters improve the secretion of glands, which helps improve digestion, assimilation of fats, proteins and carbohydrates. You need to take this water within 10-15 minutes. before eating, warm it up a little before eating. Most often, such water can be easily distinguished from others by its salty taste.

Not only the type of water is important, but also the temperature. Warm mineral water helps with gastritis with increased acidity and at . Cold water is used for intestinal atony and a tendency to constipation. In other cases, it is necessary to use water with a temperature of 33 to 44 degrees.

The dosage of mineral waters can also vary greatly, because... different diseases require different types mineral waters with different concentrations, dosage and course of application.

BENEFITS AND HARMS OF MINERAL WATER

Mineral water can be used in the treatment of many diseases. However, this cannot act as the main method of treating the disease, but only as helper method. Adding a course of mineral water to the treatment course of a specific disease makes it easier to overcome the disease.

However, mineral water can also be harmful. Carbon dioxide in mineral water increases the secretion of gastric juice, which in case of gastritis with high acidity in the stomach can only aggravate the situation.

TABLE WATER

Most of the bottled water found in stores is table water or also called soda water. This is ordinary fresh water (mineralization up to 1 g/dm3), which is artificially saturated with carbon dioxide with a slight addition calcium chloride and magnesium chloride.

By looking at the label of the bottled water offered in the store, you can determine the type of mineral water. Those. having determined whether the water is more of a table water, thirst-quenching water, or still more of a healing waters. It is necessary to look at the mineral composition of the water; if the label indicates the concentration of various components, then this type of water is mostly classified as medicinal water. If nothing is indicated on the label, then this is ordinary fresh water for table use.

It makes sense to use table water only to quench thirst and not for medicinal purposes.