Mineral Waters

subterranean (sometimes surface) waters characterized by a high content of biologically active mineral components (less frequently, organic components) and/or having specific physicochemical properties, such as chemical composition, temperature, and radioactivity, as a result of which they exert a therapeutic effect on the human body. Mineral waters may be used as external or internal therapeutic agents, depending on their chemical composition and physical properties.

Principles of formation and distribution. The process of formation of mineral waters is extremely complex and has not yet been sufficiently studied. In characterizing the genesis of mineral waters, the origin of the subterranean water itself and of the gases present in it, and also the formation of its ion and salt composition, is distinguished.

Processes that participate in the formation of mineral waters are infiltration of surface waters, burial of seawater during accumulation of sediment, freeing of waters of constitution in regional and contact metamorphism of rock, and volcanic processes. The composition of mineral waters is conditioned by the history of geological development, the character of the tectonic structures, lithology, geothermal conditions, and other features of the territory. The most powerful factors in the formation of the gas composition of mineral waters are metamorphic and volcanic processes. The volatile products (CO₂, HC1, and so on) that are evolved during these processes enter subterranean waters and impart high aggressiveness to them, which fosters the leaching of surrounding rock and the formation of the chemical composition, mineralization, and gas saturation of the water. The ion-salt composition of mineral waters is formed with the participation of processes of dissolution of salt-bearing and carbonate deposits, and also of cation exchange.

The gases dissolved in mineral waters are indicators of the geochemical conditions under which the formation of the waters took place. In the upper zone of the earth’s crust, where oxidative processes predominate, mineral waters contain gases of atmospheric origin, such as nitrogen, oxygen, and carbon dioxide (in insignificant volumes). Hydrocarbon gases and hydrogen sulfide attest to the chemical reduction conditions characteristic of the deeper strata of earth; a high concentration of carbon dioxide permits the assumption that the water containing it was formed under metamorphic conditions.

On the surface of the earth, mineral waters appear in the form of springs; they may also be brought up from the depths through boreholes up to several kilometers deep. Sources of subterranean mineral waters with a strictly determined use potential (usable reserves) are developed for practical use.

Mineral-water provinces, each of which is distinguished by the hydrogeological conditions, features of geological development, origin, and physicochemical characteristics of its mineral waters, are set aside in the USSR and foreign countries.

Isolated stratal systems of artesian wells consist of provinces of salty and brackish waters of varied ionic composition, with mineralization up to 300–400 grams per liter (g/l), and sometimes up to 600 g/l, they contain gases of reduction conditions (hydrocarbons, hydrogen sulfide, and nitrogen). Plicated regions and areas of rejuvenated platforms correspond to provinces of cold and thermal carbonic-acid mineral waters of various degrees of mineralization. Areas with manifestations of the most recent tectonic movements belong to the province of nitrogenous, slightly mineralized, alkaline, often siliceous thermal springs. The USSR is especially rich in carbonic-acid mineral waters (the Caucasian, Transbaikalia, Primor’e, and Kamchatka provinces).

In the USSR, the following types of mineral-water deposits are distinguished, depending on the structural confinement and associated hydrodynamic and hydrogeochemical conditions: platformlike artesian wells (Kashin, Staraia Russa, Tiumen’, and Sestroretsk), foothill and intermontane artesian wells arid slopes (Chartak, Tbilisi, and Nal’chik), artesian wells connected with zones of ascending discharge of mineral waters (Nagut, Essentuki, and Dzhalal-Abad), interstitial-vein waters of hydrogeological massifs (Istisu, Kul’dur, and Belokurikha), hydrogeological massifs associated with zones of ascending discharge of mineral waters into strata of groundwater (Kurort-Darasun, Shivanda, and Shmakovka), and ground mineral waters (Martial’nye Vody, Uvil’dy, Kisegach, and Borovoe).

Therapeutic effects. Mineral waters exert a therapeutic effect on the human body by means of the entire complex of substances dissolved in them, and the presence of specific biologically active components (such as CO₂, FhS, and As) and special properties often determines the methods of their therapeutic use. In Soviet health resort science the basic criteria that have been accepted for evaluating therapeutic mineral waters are the particular features of their chemical composition and physical properties, which simultaneously serve as the most important indexes in classifying them.

The mineralization of mineral waters—that is, the sum of all water-soluble substances (ions and biologically active elements, except gases)—is expressed in grams per liter of water. The following degrees of mineralization are distinguished: weak (1–2 g/l), low (2–5 g/l), medium (5–15 g/l), high (15–30 g/l), brackish (35–150 g/l), and highly brackish (150 g/l and more). Mineral waters for internal use usually have a mineralization of 2–20 g/l.

Mineral waters are classified according to ionic composition as chloride (Cl^-), hydrocarbonate (HCO₃^-), sulfate (SO₄^2-), sodium (Na⁺), calcium (Ca²⁺), and magnesium (Mg²⁺), with various combinations of anions and cations. The following mineral waters are distinguished according to the presence of gases and specific elements: carbonic-acid, sulfide (hydrogen sulfide), nitrogen, bromine, iodine, ferriferous, arsenical, siliceous, and radioactive (radon). Mineral waters are classified according to temperature as cold (up to 20°C), warm (20°-37°C), hot (thermal; 37°-42°C), and very hot (42°C and up). The content of organic matter in waters with low mineralization takes on great significance in medical practice, since it determines their specific properties. A content of organic substances of more than 40 mg/l makes the waters unsuitable for internal use.

Special standards have been developed that make possible evaluation of the suitability of natural waters for therapeutic purposes (see Table 1).

The composition of mineral waters is indicated according to a formula proposed by the Soviet scientists M. G. Kurlov and E. E. Karstens. The beginning of the formula gives the content of gas (CO₂, H₂S, and so on) and active elements (Br, I, Fe, As, and so on) in grams per liter. Radioactivity is expressed in Maché units or in disintegrations per sec-m³ (1 Mache unit = 1.3 X 10⁴ disintegrations per sec-m³). The degree of mineralization is designated by the symbol M (the sum of anions, cations, and undissociated molecules) and is expressed in grams. The ratio of the predominant anions and cations is represented in the form of a conventional fraction, in which the numerator shows the predominant anions and the denominator shows the cations. At the end of the formula the temperature (T) of the water as it emerges at the spring is indicated in degrees Celsius, and the pH value is shown last.

The following is an example of a formula characterizing Narzan, a potable mineral water from Kislovodsk:

This formula is read as follows: a carbonic-acid-hydrocarbonate-sulfate, calcium-magnesium water with mineralization of 2.3 g/l, temperature of 14°C, and pH of 6.2.

Mineral waters are used at health resorts for beverage therapy, baths, bathing in therapeutic pools, all types of showers, inhalation and gargling in the case of diseases of the throat and upper respiratory tract, and irrigation in the case of gynecological diseases. (For external uses of mineral water, seeBALNEOLOGY, BALNEOTHERAPY, and BATHS.)

Mineral waters are also taken internally outside of health resorts, when imported bottled waters are used. As of 1974 there were more than 100 plants and departments for bottling minera waters in the USSR, with an output of more than 900 million bottles per year. The bottled water is saturated with carbon dioxide to preserve its chemical properties and flavor; it must be colorless and absolutely pure. Bottles of mineral water are stored in a horizontal position in a cool place. Treatment with bottled mineral waters must be combined with observance of a definite regimen and diet and the use of supplementary therapeutic factors (physiotherapy, medication, hormone therapy, and so on).

Mineral waters of predominantly low mineralization, containing ions of calcium, have an a pronounced diuretic effect, and foster the discharge of bacteria, mucus, sand, and even small concretions from the kidneys, renal pelvis, and urinary bladder. The use of mineral waters is contraindicated, for example, in the presence of esophagostenosis and pyloristenosis, severe gastroptosis, cardiovascular disease accompanied by edema, or disturbances of the excretory capacity of the kidneys. Treatment with mineral waters must be conducted according to a physician’s prescription and under a physician’s supervision.

(For detailed information on the principal bottled mineral waters, their chemical composition, and indications for use, seeARSHAN, ARZNI, BATALIN SPRING, BEREZOVSKIE MINERAL’-NYE VODY, BORZHOMI, DILIZHAN, DRUSKININKAI, DZHERMUK, ESSENTUKI, IAMAROVKA, ISTISU, IZHEVSKIE MINERAL’NYE VODY, KARMADON, KASHIN, KISLOVODSK, KRAINKA, KUKA, KURORT-DARASUN, LUGELA, , SAIRME, SHIVANDA, SHMAKOVKA, SLAVIANOGORSK, SMIRNOV SPRING, TRUSKA-VETS, and ZHELEZNOGORSK.)

In Europe, carbonic-acid mineral waters are widespread in central France (Vichy), the Federal Republic of Germany (Bad Nauheim, Bad Ems, and Bad Wildungen), and Czechoslovakia (Karlovy Vary and Marianske Lazne). Hydrosulfite nitrogen warm and hot mineral waters are found on the border of France and Spain in the Pyrenees, in the French health resort of Aix-les-Bains, and in Czechoslovakia (Teplice); hot nitrogen waters are used in Budapest, Hungary, and in the vicinity of Sofia, Bulgaria. There are many outlets of hot nitrogen mineral waters in regions of recent volcanic activity (the USA, Iceland, Italy, New Zealand, and so on). Hydrogen-sulfide mineral waters are found in the Federal Republic of Germany (Aachen), Austria (Baden), Rumania (Baile Herculane), and Turkey (Bursa).

Artificial mineral waters are manufactured from chemically pure salts, according to strict analogy with natural mineral waters. However, complete identity of composition with natural waters is not attainable. Imitation of the composition of dissolved gases and of the properties of colloids presents special difficulties. The only artificial mineral waters that have become widespread are carbonic-acid, hydrogen-sulfide, and nitrogen waters, which are used mainly for bathing. The Central Institute of Health Resort Science and Physiotherapy (Moscow) has proposed methods of producing several beverage mineral waters with high therapeutic value (of the type of Essentuki no. 17, Borzhomi, and Batalin); however, artificial beverage mineral waters have not become widespread in the USSR, since each year the number of balneological and beverage health resorts and boreholes yielding mineral waters increases, and the bottling of mineral waters increases correspondingly.

Some mineral waters are used as refreshing, thirst-quenchin table beverages that promote increased appetite; they are used instead of fresh water, without any medical indications. In a number of regions of the USSR the ordinary drinking water is heavily mineralized, and its use as a table beverage is completely justified. Mineral waters of the chloride-sodium type, with mineralization no higher than 4.0–4.5 g/l (for hydrocarbonate waters, about 6 g/l) may be used as table beverages.