WATER that we drink

It is impossible to overestimate the importance of such an environmental factor as water, which is rightfully considered the basis of life of all things on Earth.

The most important factor in preserving and strengthening people's health is providing them with high-quality drinking water. Therefore, issues of improving the water supply of the population have always been a priority in government policy to protect the health of citizens.

The value of water. Three quarters of the Earth’s surface are occupied by water - oceans, seas, lakes, rivers, and a fifth of the land is covered with snow and ice. Animals and plants are mostly composed of water, including humans: water makes up 70% of our body mass.

The second most important property is the ability of water to dissolve substances. Water is a universal solvent. Water contains almost all the elements of the Periodic Table, as well as gases, bases, acids, salts and organic substances.

The third unique property of water is that on Earth it is present simultaneously in three states or in three phases - gaseous, liquid and solid (water vapor, water, ice).

The composition of the water. Water - a solution consisting of many chemicals of technogenic and natural origin. In water there are:

· Separate chemical elements (more precisely, their ions) - light metals (lithium, sodium, potassium, magnesium, calcium), heavier metals (chromium, manganese, iron, zinc, mercury, etc.) and even silver, gold and radioactive elements. There is carbon, phosphorus, sulfur, iodine;

· Gases - oxygen, ozone, fluorine, chlorine; may be methane, hydrogen sulfide, radon. Gases give water a particular odor;

· Inorganic substances - salts, acids, alkalis;

· Organic matter; some of them are relatively harmless to humans, others are undesirable, and still others are real poison;

· Insoluble organic impurities of organic and inorganic origin - sand, silt, rust, clay particles and so on. They impart turbidity to the water and precipitate upon sedimentation.

Water classification.

From ancient times, waters have been divided into salty and fresh. Salt waters contain an increased concentration of salts, primarily sodium. They are unsuitable for drinking and industrial use.

Fresh water . It differs in two main organoleptic indicators - smell and taste. Fresh water, depending on the composition, is divided into two large groups: plain water and mineral , that is, water with a high content of useful inorganic components. Moreover, within each group, water is very different in composition due to geological and geographical reasons. This is a classification of waters of natural origin, but there are artificial waters created by humans purposefully: artificial mineral water, distilled water, as well as special waters saturated with one or another component, such as silver. Recently, water from various springs, which is considered to be pure and harmless by definition, has been very popular among the population. Some springs were declared saints, and their popularity reached unprecedented proportions.

According to Vsevolod Chaplin, an employee of the Department for External Church Relations of the Moscow Patriarchate, there is no special procedure for declaring a source a saint. Recognizing the source as holy does not mean that the water from it is safe. Honoring the source is a matter of faith, not an assessment of water quality.

Distilled water   - water with insignificant, practically undetectable chemical and physical methods, impurities of foreign substances. It is used for medical and research purposes. EE is produced by evaporation of ordinary fresh water followed by condensation of steam. Distilled water cannot replace ordinary drinking water, since vital minerals are not absent in it. With prolonged use of only distilled water, especially against fasting, functional disorders will occur: heart rhythm disturbances, headaches, muscle cramps, as well as problems with the teeth and bone system.

Normal fresh water.   There are several important indicators of fresh water quality: pH, hardness and organoleptic.

pH is related to the concentration of hydrogen ions in the medium and gives us an idea of \u200b\u200bthe acid or alkaline properties of water

pH less than 7 - acidic environment;

pH \u003d 7 - neutral medium;

pH greater than 7 - alkaline environment.

Hardness is the property of water, due to the content of calcium and magnesium ions in it.

Organoleptic characteristics of water are understood to mean its smell, color, and turbidity.

Drinking water   must meet the standards. There are several standards for drinking water: the Russian standard defined by the relevant GOSTs, the WHO standard, the US standard and the EU standard.

The parameters of drinking water are divided into three groups: organoleptic properties, indicators of bacterial and sanitary-chemical pollution. About organoleptic properties was mentioned above. The remaining parameters are determined by components that may be present in water and in what quantities (MPC - maximum permissible concentration). MPC is defined as the dose of a harmful substance that can be taken without consequences with water every day throughout life. At the same time, it is taken into account that a person drinks 2 - 2.5 liters of water per day. MPC standards are calculated for the average person - an adult and relatively healthy. However, more than half of the world's population are children, the elderly and the sick. These categories are the most vulnerable, and the effect of harmful substances on them is the least studied.

High quality drinking water indicators:

· Organoleptic characteristics of water - transparent, odorless and with a pleasant taste;

· This is water with pH \u003d 7 - 7.5 and hardness not higher than 7 mmol / l;

· This is water in which the total amount of useful minerals is not more than 1 g / l;

· This is water in which harmful chemical impurities either make up tenths or hundredths of their maximum permissible concentration or are completely absent

· This is water in which there are practically no pathogenic bacteria and viruses.

Water purification.

Water purification in order to prepare it for drinking, household and industrial purposes is a complex of physical, chemical and biological methods of changing its initial composition. By water purification is understood not only its purification from a number of undesirable and harmful impurities, but also the improvement of natural properties by enriching it with the missing ingredients. The whole variety of water treatment methods can be divided into the following main groups:

· Improvement of organoleptic properties of water (lightening and discoloration, deodorization, etc.),

· Ensuring epidemiological safety (chlorination, ozonation, ultraviolet radiation, etc.),

· Conditioning of the mineral composition (fluorination and defluorination, extraction of heavy metal ions, iron removal, softening or desalination, etc.).

The method of water purification is chosen on the basis of a preliminary study of the composition and properties of the water of the source intended for use, and their comparison with the requirements of the consumer.

Water disinfection (water disinfection) - a set of measures taken to purify water from microorganisms (viruses, bacteria, cysts, etc.). As numerous studies show, the quality of drinking water largely depends on the method and mode of disinfection. Existing methods of disinfection of drinking water are divided into reagent, reagent-free and combined.

In combined water disinfection methods, two disinfection methods or two disinfectants are used, one of which is able to maintain its activity in water for a long time.

Ozonation of water is a more high-tech way of treating water. Ozone is an allotropic modification of oxygen. At normal temperature, it spontaneously dissociates, especially in water. With increasing water temperature, the decomposition of ozone increases. The bactericidal effect of ozone is associated with the active penetration of this chemically active form of oxygen through cell membranes and the subsequent oxidation of organic substances, which causes the death of a bacterial cell. Along with disinfection, ozonation leads to improved taste and the elimination of water odors.

The interest in the use of ozone in the preparation of drinking water is explained by the fact that ozone as a strong oxidizing agent has several advantages over other reagents. Ozonation not only provides quick and reliable disinfection, but also causes a very significant improvement in the organoleptic properties of water, because as a result of treatment with ozone, tastes and odors, water color are eliminated. In addition, the content of dissolved oxygen increases, which returns purified water to one of the main properties that characterize pure natural sources.

Ozonation also allows you to remove iron and manganese from water in cases where other well-known methods do not give satisfactory results.

From a physical point of view, water after ozonation undergoes significant qualitative changes. In a sufficiently large layer, the water acquires a beautiful bluish color, characteristic of spring water. During ozonation, water is well aerated, which makes it more digestible and pleasant for drinking consumption ..

From the organoleptic point of view, in ozonized water not only no tastes and smells arise (which is inevitable during chlorination), but, on the contrary, any traces of taste and odor that previously existed in the treated water are eliminated.

From a chemical point of view, mineral substances dissolved in water and determining to some extent the nutritional properties do not change after ozonation. At the same time, ozone treatment does not give water any additional foreign substances and chemical compounds.

In an ozone water treatment plant, water goes through several stages of purification and becomes a natural disinfector. Such purification does not lead to the formation of dangerous carcinogenic and mutagenic substances in water, as is the case with water chlorination. And it is even healing, as it is saturated with oxygen! The crystals of ozone-purified water are very different from ordinary drinking. After ozone purification, the physiological usefulness of water is preserved with respect to micro and macro elements necessary for the human body, such as in rain water. Therefore, for about 30 years in Europe, people have been drinking ozone-purified water.

Purification of drinking water at home.

Post-treatment, which is also called finishing cleaning, or cleaning "on the tap."

Simple ways to purify water.

· Discharge of stagnant water. It is better to collect water for drinking for the future in the amount of 5 -10 liters in the evening, when the water does not stagnate in the pipes.

· Water sedimentation. The water collected in the evening must be allowed to settle overnight - best in closed glass, ceramic or enameled containers (but not in aluminum or steel). The lower third of the water volume (through a tube) merges into which during the settling time impurities of heavy metals have dropped.

· Boiling water. Boiling kills microorganisms, and at the same time almost all chlororganic matter leaves the water along with steam. Boil water for 5 to 7 minutes in a container without a lid. It is necessary to store treated water in a sealed container and preferably in a refrigerator.

Mineral water.

WHO experts believe that mineral concentration is not important for mineral water, but its origin.

And if the water is extracted from a specific source, which is well studied, and without being subjected to any further processing, is bottled, then this is mineral water.

Natural water with a high content of mineral components is classified into four groups.

1. Mineral healing water with high salinity of more than 8 g / l. Take as directed by a doctor.

2. Mineral table water with a total salinity of 2 - 8 g / l. Accepted as prescribed by the doctor, but can be used as a dining room.

3. Mineral table water with a salinity of 1 - 2 g / l.

4. Table water with a salinity of less than 1 g / l.

The name of water may include the definition of "hydrocarbonate" and "sodium", etc., depending on the predominance of certain mineral components. Mineral water may be acidic, neutral, or alkaline. The effect of each on the gastrointestinal tract and the body as a whole will be different.

Artificial water.

These are waters made with the help of various technologies.

Water with "wonderful" properties.

Melt water . It cannot be made of snow and ice in the city - it is life threatening, as it is very dirty.

Home cooking method: freeze 0.5 containers until ice forms, pour out the remainder.

Shungite water . Shungite is a rock formation. Natural water with a high iron content. The healing properties of artificial shungite water are doubtful. Adding shungite to the filters is not effective as it is very short-lived.

Silver water . The bactericidal properties of silver have been known since antiquity and are confirmed by modern science. On an industrial scale, disinfection of water by the method of electrolytic saturation of water with silver ions is not used because of the high cost (silver is a precious metal) and the difficulty of maintaining strict parameters for the concentration of silver in water. It must be remembered that silver is a heavy metal and its saturated solutions are harmful to health. The maximum concentration limit of silver in water is 0.05 mg / l.

None of the serious scientific sources classifies silver as a vital bioelement. And, in addition to its beneficial properties, there are also harmful ones. Especially if there is an excess of silver.

"Living" and "Dead" water   it is nothing more than a poetic metaphor. Modern science does not have reliable data on the unusual properties of this water.

"Structured" water or magnetized water.   This is water passed through a magnetic field and attributed to its amazing healing properties. However, modern medicine and biology denies the presence of these properties in water. When a magnetic field acts on water, its structure changes, but for a very short time. Remove this field, and in billions of a second, the water will be in its original state.

10 reasons to drink more water

Thirsty, mankind for many centuries quenched it with ordinary drinking water. Now they are trying to replace her. And many do not even suspect how important water is for health, beauty and figure.

Thirsty, mankind for many centuries quenched it with ordinary drinking water. But not everything is so simple in the modern world ruled by carbonated drinks, alcohol and caffeine. By washing down our thirst with them, we forget that ordinary drinking water is not only useful, but also vital for the body. Many do not even suspect how important water is for health, beauty and figure. Quality drinking water:

1. Improves and rejuvenates the skin

Modern women of fashion spend fortunes on cosmetics for face and body skin care, while completely ignoring the cheapest and most effective product - water. Daily use of drinking water leads to an improvement in the vital functions of cells, moisturizes the skin from the inside, increases its elasticity, and prevents dryness.

2. Removes toxins from the body

Water helps remove toxins from the digestive tract. As you know, the kidneys are a natural "filter" of the body and this ability depends on the amount of water consumed.

3. Reduces the risk of heart attack

A recent study showed that people who drink at least 5 glasses of plain water per day have a lower risk of heart attacks compared to those who drink 2 glasses of water per day.

4. Is a “lubricant” for joints and muscles

Water is the main material for the formation of a special fluid, which is a kind of "lubricant" for joints and muscles. Athletes (especially those who have devoted themselves to power sports) have long known that a lack of water in the body leads to muscle cramps. Even if your acquaintance with sports comes down to daily morning exercises, remember that to prevent muscle cramps, you should drink water before, during and after sports.

5. Restores energy

On average, during the day a person loses about 10 (!) Glasses of liquid (during the processes of sweating, breathing, urination and defecation). Even the slightest dehydration can result in loss of concentration, headaches, irritability and fatigue.

The body needs water to function properly. The oxygen level in the circulatory system directly depends on the amount of water we drink. The more oxygen in the body, the more fat will be burned for energy. With a small amount of oxygen, the body cannot "utilize" fat and turn it into energy.

Researchers have confirmed that water is also necessary for the proper functioning of the brain.

6. Supports the digestive system

Water not only prevents the formation of constipation, but also participates in the digestion process and the formation of chemical reactions of this process. The carbohydrates and proteins that our body uses as food are absorbed and transferred to the circulatory system using water. Using the same water, waste products are excreted from the body (urination process).

7. Reduces the risk of diseases and infections.

Lack of water in the body can lead to a dangerous disease - chronic dehydration of cells. The cells of the body constantly do not get the right amount of water, which leads to a decrease in their vital activity and opens the way to the occurrence of various diseases due to a general decrease in immunity.

8. Regulates body temperature

Water regulates the "cooling system" of the body. After active sports, steamed and sweaty athletes often attack the so-called "sports" drinks. However, many experts agree that water as a temperature regulator "works" better than widely advertised soda with sugar.

You will be surprised, but water is the nutrient that the body needs in the greatest amount. From 55% to 75% of the weight of an average adult is precisely water, which is involved in the process of thermoregulation.

9. Burns fat and sculpts new muscles

As mentioned above, dehydration slows down protein synthesis, which is crucial for muscle formation. The process of formation of new muscle tissue is energy-intensive. The fewer calories burned and converted into energy to create new muscles, the more calories will be "deposited" in the body in the form of excess fat.

10. Improves overall health

The traditional wording of the local doctor pronounced at the bedside of a patient with acute respiratory infections or the flu - "and drink plenty of fluids" - must be taken with all seriousness. Water helps control heat by replenishing fluid lost by the body and removing mucus.

Water is an important part of our life. Try to drink more water before, during and after physical exertion, on hot days, at low humidity, at a high altitude, experiencing an attack of nausea, diarrhea, with an increase in body temperature. However, it is important to remember that the body is able to absorb about 120 milliliters of water every 10 minutes, so do not overdo it.

Accustom yourself to drink a glass of water every hour. Make this process fun:

- Add a little mint, slices of fresh strawberries, apple, lemon or lime to a glass of clean water. Drink “fruit water” chilled.

- Instead of regular black tea, drink herbal infusions. Try rosehip, chamomile, apple, menthol tea, mate and traditional Chinese green tea.

- Add a little juice of fresh lemon to a glass of clean water. Warm water with lemon, drunk in the morning on an "empty stomach" removes toxins from the liver and helps to fight excess weight.

Remember that high-quality drinking water should be free from foreign matter, active, vibrant, capable of assimilating useful ingredients.

Water purification for cooking

It is possible that we never tasted the real taste of the prepared dishes, literally never in our lives. What we eat, products only in a defective, distorted form. No vegetables, no fish, no meat.

We rightly care about the origin, quality and purity of each ingredient that forms our dishes. However, there is a component that we use daily, without paying any attention to it. This is water. Its properties are usually for some reason not questioned. But if we make a chemical analysis of the water that we pour into the pan, for example, from a jug filter, from a bottle bought in a store or directly from a water tap, it turns out that we are dealing with different water each time. And each of these waters in its own way affects the cooking process.

It is in the water that many, many dishes are formed - from the daily potatoes to the anniversary Finnish soup. Water acts as a universal medium that combines all the components of a future dish, extracting various substances from them and ... adding to them their own - those that were in it itself - by the will of fate. In the test of my grandmother’s pie there is a pinch of sodium hypochloride, cheaply and angrily thrown at the city water treatment station - against dysentery. In the borsch - pieces of rust almost invisible to the eye, but palpable to taste, from the walls of pipes laid even decades ago. And almost certainly - brown flakes of iron, which managed to oxidize from a divalent state to a trivalent state and precipitate - just at that time, while they cooked delicious trout grown in ecologically clean conditions of trout farming. Hardness salts, forming a well-known scale, not only on the surface of pots and dummies, but also - naturally! - on every slice of cabbage, carrots and meat that we threw into the soup. The list of impurities can be continued for a very long time, but the appetite for this is unlikely to improve.

Cooking foods with impurities is about the same as watching a TV show with noise and interference. Foreign substances mask the true taste of the food and distort it. In order to fully reveal and feel the organoleptic properties of your favorite product or dish - its taste, smell and, importantly, color - you need to cook it in perfectly clear water. The formation of taste and smell is a complex process. This is precisely the culinary art. And the art of maintaining health is the constant use of purified water.

About the benefits of drinking water.

Everyone knows that the human body consists of about 80% of water, and this water must be updated every 7 to 10 days! Therefore, not only the renewal of our body, but above all our health depends on the quality of drinking water.

It has long been talked that a person should drink 2 to 3 liters of water per day. It is pure drinking water! Pure mountain drinking water is characterized by a low salt content and a balanced composition of trace elements, which helps to improve the body's vital functions.

Drinking water is a determining factor in your health! Why is drinking water considered a useful and indispensable product? Here are a number of factors that drinking water has:

1. Helps to eliminate toxins and toxins;
2. Increases vitality of your body;
3. The prescribed amount of drinking water per day helps to reduce weight;
4. Thanks to drinking water, digestion and blood circulation improves;
5. It does not contain chlorine and therefore helps strengthen tooth enamel.

Pure drinking water is not only high-quality and mild-tasting water, but also the key to your health.

People are often addicted to the use of mineral water, not taking into account that its composition includes its own unique set of chemical elements, which determines its benefit or harm. However, before ordering mineral water, you should know what it is in its composition:

1. medical;
2. medical and dining room;
3. canteen.

Mineral water is very useful for:

1. peptic ulcer and gastritis;
2. chronic liver disease;
3. pancreatitis;
4. improper metabolism.

For everyday use, drinking table water is used.
In case of non-compliance of water with standards, it is cleaned and disinfected. Water purification implies the release of water from suspended particles, turbidity, from unusual colors, odors and flavors, from excess salts and gases. Water purification and disinfection is carried out by various means, filters from a porous substance (coal, calcined clay) are used; ionizers, etc.

In order to feel good, a person should only use clean, high-quality drinking water. Scientists have long established a direct relationship between the quality of drinking water and life expectancy. According to the World Health Organization, about 80% of human diseases are caused by drinking poor-quality water for drinking needs.

High-quality drinking water should not have substances harmful to humans, and should contain useful minerals that are necessary for the normal functioning of our body.

Water is the source of life, a determining factor in your health and longevity. Water accompanies a person throughout the day and therefore its presence is natural, habitual, and therefore invisible.

GBUZ "Center for Medical Prevention"

Water, as you know, is not only the most common substance in nature, but also a universal solvent. More than 2000 natural substances and elements were found in water, of which only 750, mainly organic compounds, were identified. However, water contains not only natural substances, but also toxic technogenic substances. They fall into water basins as a result of industrial emissions, agricultural drains, household waste. Thousands of chemicals with unpredictable environmental effects fall into water sources every year, hundreds of which are new chemical compounds. In water, elevated concentrations of toxic heavy metal ions (for example, cadmium, mercury, lead, chromium), pesticides, nitrates and phosphates, oil products, surfactants can be detected. Every year, up to 12 million falls into the seas and oceans. tons of oil. Acid rains in industrialized countries also make a certain contribution to the increase in the concentration of heavy metals in water. Such rains can dissolve minerals in the soil and increase the content of toxic heavy metal ions in water. Radioactive waste from nuclear power plants is also involved in the water cycle. Discharge of untreated sewage into water sources leads to microbiological contamination of water. According to the World Health Organization, 80% of diseases in the world are caused by low quality and unsanitary conditions of water. The problem of water quality is especially acute in rural areas - approximately 90% of all rural inhabitants in the world constantly use polluted water for drinking and bathing.

For several reasons. First, the formation of standards for drinking water is based on an expert assessment based on several factors that often do not take into account technogenic pollution of the water and have some uncertainty in substantiating conclusions about the concentrations of pollutants affecting a living organism. As a result, the recommendations of the World Health Organization allow, for example, one cancer in one hundred thousand people due to water. Therefore, WHO experts already on the first pages of the Guidelines for the Control of Drinking Water Quality (Geneva, WHO) declare that “despite the fact that the recommended values \u200b\u200bprovide the quality of water acceptable for consumption throughout life, this does not mean that the quality of drinking water can be reduced to the recommended level. In reality, constant efforts are required to maintain the quality of drinking water at the highest possible level ... and the level of exposure to toxic substances should be as low as possible. ” Secondly, the possibilities of states in this regard (the cost of treatment, distribution and monitoring of water) are limited, and common sense suggests that it is unreasonable to perfect all the water supplied to the house for household and drinking needs, especially since approximately one percent of all water used. Thirdly, it happens that efforts to purify water at wastewater treatment plants are neutralized due to technical violations, accidents, replenishment of contaminated water, and secondary pipe pollution. So the principle of "protect yourself" is very relevant.

Recently, in scientific and practical circles in the field of water treatment at conferences and symposia, the question of the effectiveness of a particular method of water disinfection has been quite actively discussed. There are three most common methods of water inactivation - chlorination, ozonation, and ultraviolet (UV) irradiation. Each of these methods has certain disadvantages that do not allow completely abandoning other methods of water disinfection in favor of any chosen one. The most preferable from a technical, operational, economic and medical point of view could be the UV irradiation method, if not for the absence of an extended disinfecting effect. On the other hand, improving the chlorination method based on bound chlorine (in the form of dioxide, sodium hypochlorite or calcium) can significantly reduce one of the negative side effects of chlorination, namely, reduce the concentration of carcinogenic and mutagenic organochlorine compounds by five to ten times. Nevertheless, the problem of viral water pollution remains unresolved - the chlorine effectiveness against viruses, as you know, is low, and even hyperchlorination (with all its disadvantages) is not able to cope with the task of complete disinfection of the treated water, especially with a high concentration of organic impurities in the treated water. The conclusion suggests itself - to use the principle of the combination of methods when the methods are mutually complementary, solving the set task in a complex. In this case, the consistent application of UV irradiation methods and the dosed introduction of bound chlorine into the treated water most effectively meet the main purpose of the disinfection system - the complete inactivation of the disinfection treatment object with a prolonged aftereffect. An additional bonus in the tandem UV-linked chlorine is the ability to reduce the power of UV radiation and chlorination doses compared to those used separately when using the above methods, which gives an additional economic effect. The proposed combination of disinfection methods is not the only one possible today and work in this direction is encouraging.

Nitrogen compounds are present in water, mainly from surface sources, in the form of nitrates and nitrites and are substances with a sanitary-toxicological indicator of harmfulness. According to SanPiN 10-124 RB99, the MPC of nitrates for NO3 is 45 mg / l (hazard class 3), and nitrites for NO2 is 3 mg / l (hazard class 2). Excessive amounts of these substances in water can cause oxygen starvation due to the formation of methemoglobin (a form of hemoglobin in which the heme iron is oxidized to Fe (III), unable to carry oxygen), as well as diseases of some forms of cancer. The most susceptible to methemoglobinemia are infants and newborns. The issue of purification of drinking water from nitrates is most acute for rural residents, since the widespread use of nitrate fertilizers leads to their accumulation in soil, and then, as a result, in rivers, lakes, wells and shallow wells.

Today, there are two methods to remove nitrates and nitrites from drinking water - on the basis of reverse osmosis and on the basis of ion exchange. Unfortunately, the sorption method (using activated carbon) as the most affordable is characterized by low efficiency.

The reverse osmosis method is extremely effective, but its high cost and total desalination of water should be considered. To prepare water for drinking needs in small quantities, it should still be considered the most suitable way to purify water from nitrates, especially since there is the possibility of connecting an additional stage with a mineralizer.

The ion exchange method is implemented in practice in installations with strongly basic anion exchange resin in the Cl form. The process of removing dissolved nitrogen compounds consists in replacing Cl– ions on the anion exchange resin with NO3– ions from water. However, in this case, SO4–, HCO3–, Cl– anions also participate in the exchange reaction, moreover, sulfate anions are more efficient than nitrate anions and the capacity for nitrate ions is low. When implementing this method, one should additionally take into account the limitation of the total concentration of sulfates, chlorides, nitrates, and bicarbonates by the MPC value for chloride ions. To overcome these shortcomings, special selective anion-exchange resins have been developed and are offered, the affinity of which with respect to nitrate ions is the highest.

The action of oxygen dissolved in water in the form of O2 molecules is reduced mainly to the effect on redox reactions involving metal cations (for example, iron, copper, manganese), nitrogen and sulfur-containing anions, and organic compounds. Therefore, when determining the stability of water and its organoleptic qualities, along with measuring the concentration of organic and inorganic substances, pH, it is important to know the oxygen concentration (in mg / l) in this water.

The water of underground sources, as a rule, is extremely depleted of oxygen, and the absorption of oxygen in the air during its extraction and transportation in water distribution networks is accompanied by a violation of the initial anionic-cationic balance, leading, for example, to precipitation of iron, a change in the pH of the water, and the formation of complex ions. Manufacturers of mineral and drinking bottled water, extracted from great depths, often have to deal with such phenomena. In the water of surface sources, the oxygen content varies greatly depending on the concentration of various organic and inorganic substances, as well as the presence of microorganisms. The oxygen balance is determined by the equilibrium of the processes leading to the flow of oxygen into water and its consumption. The increase in the oxygen content in water is facilitated by the processes of oxygen uptake from the atmosphere, the release of oxygen by aquatic plants during photosynthesis, and the replenishment of surface sources with oxygenated rain and melt water. The speed of this process increases with decreasing temperature, with increasing pressure and lowering mineralization. In underground sources, a small oxygen content can be caused by vertical thermal convection. Chemical oxygenation of substances (nitrites, methane, ammonium, humic substances, organic and inorganic waste in wastewater of anthropogenic origin), biological (respiration of organisms) and biochemical consumption (respiration of bacteria, oxygen consumption during decomposition of organic substances). The rate of oxygen consumption increases with increasing temperature and the number of bacteria. A quantitative characteristic of chemical oxygen consumption is based on the concept of oxidizability - the amount of oxygen in mg spent on the oxidation of organic and inorganic substances contained in 1 liter of water (the so-called permanganate oxidation for slightly polluted waters, and bichromate oxidation (or COD - chemical oxygen consumption). Biochemical oxygen consumption (BOD, mg / l) is considered as a measure of water pollution and is defined as the difference in the oxygen content in water before and after it is kept in the dark in those 5 days at 20 ° C. Water with a BOD of not higher than 30 mg / l is considered to be practically pure.

Although WHO experts do not provide a quantitative description of the oxygen in drinking water, they nevertheless recommend "... to maintain the concentrations of dissolved oxygen as close to the saturation level as possible, which in turn requires that the concentrations of biologically oxidizing substances ... be as low as possible." From a technical point of view, oxygenated water exhibits corrosive properties to metal and concrete, which is undesirable. A compromise is the degree of saturation (relative oxygen content as a percentage of its equilibrium content) of 75% (or equivalent from 7 in summer to 11 in winter mg O2 / l).

In drinking water, the hydrogen indicator for sanitary standards should be from 6 to 9, and in some soft drinks there are 3-4. What is the role of this indicator and is it not harmful to drink drinks with such a low value of hydrogen?

In the WHO recommendations, the value of the hydrogen index is in an even narrower range of 6.5-8.5, but this is due to certain considerations. The hydrogen index is a value that characterizes the concentration of hydrogen ions H + (hydroxonium H3O +) in water or in aqueous solutions. Since this value, expressed in g-ions per liter of aqueous solution, is extremely small, it is customary to define it as the negative decimal logarithm of the concentration of hydrogen ions and denote it by pH. In pure water (or a neutral solution) at 250 ° C, the hydrogen index is 7 and reflects the equality of the H + and OH- ions (hydroxyl group) as components of the water molecule. In aqueous solutions, depending on the H + / OH– ratio, the hydrogen index can vary from 1 to 14. At a pH of less than 7, the concentration of hydrogen ions exceeds the concentration of hydroxyl ions and water has an acid reaction; at pH greater than 7 there is an inverse relationship between H + and OH- and water has an alkaline reaction. The presence of various impurities in water affects the pH value, determining the rates and directions of chemical reactions.

In natural waters, the ratio of the concentrations of carbon dioxide CO2, carbonic acid, carbonate and bicarbonate ions significantly affects the pH value. The presence of humic (soil) acids, carbonic acid, fulvic acids (and other organic acids as a result of decomposition of organic substances) in water lowers the pH value to 3.0 - 6.5. Groundwater containing calcium and magnesium bicarbonates is characterized by a pH close to neutral. The noticeable presence of sodium carbonates and bicarbonates in water increases the hydrogen index to 8.5–9.5. The pH of the water of rivers, lakes, groundwaters is usually in the range of 6.5-8.5, atmospheric precipitation 4.6-6.1, marshes 5.5-6.0, sea water 7.9-8.3, and gastric juice - 1.6-1.8! Technological requirements for water for the production of vodka provide a pH value of 8, the efficiency of the chlorine disinfection process decreases, and conditions are created for the precipitation of hardness salts. As a result, WHO experts conclude that "in the absence of a water distribution system, the permissible range of pH values \u200b\u200bmay be wider" than the recommended 6.5-8.5. It should be noted that when determining the pH range, diseases of the human gastrointestinal tract were not taken into account.

Still, it would seem, quite recently, the process of converting tap water into drinking water did not cause much thought among the city dweller. Not everyone considered mandatory even such a simple preparatory procedure as boiling tap water for drinking. And cooking on tap water seemed so natural that no thoughts arose about what could be somehow different.

Now about 80% of the population is provided with centralized water supply in Ukraine. However, few residents of large and not very large cities consider tap water to be quality and safe drinking water, and in any case, the use of tap water as drinking water is not included in the concept of a healthy lifestyle.

Why has the consumer attitude to tap water changed? Several global and specifically local causes can be mentioned, in particular:

• natural waters, which are sources of water supply, become dirtier; clean water reserves on the planet are drastically reduced;
• the quality of water treatment at domestic utilities in dire economic conditions raises great doubts (no matter how we treat water chlorination, but sometimes chlorine is sometimes not enough to disinfect the water supplied to the city water supply);
• consumers learned more about the composition of tap and natural waters, about the presence of pollutants of different nature in them. New, more sensitive and selective methods of analytical control have appeared, which make it possible to determine such impurities at such a level of concentrations that it was not possible to control them before;
• both information on home water purification means and the means themselves - household filters, water purifiers, as well as all kinds of improving and cleaning additives have become more accessible;
• the public is now better aware of how the problem of drinking water is solved abroad.

For the mass domestic consumer, the main source of knowledge about drinking water is, of course, advertising. Household water purification systems or water purifying additives are distributed mainly through various marketing networks, and each network accompanies its product with explanatory and persuasive leaflets, booklets, and video tapes. The very principle of network marketing - hand-to-hand dissemination - gives the perception of advertising information personal shades, and, apparently, increases its significance for the consumer compared to impersonal advertising in the media.

Regardless of the type of product and the level of argument literacy, the general meaning of this kind of information is the same: the good quality of drinking water is the care of the one who drinks this water. Without disputing this conclusion, we consider some aspects of water quality from the point of view of a chemist.

World Water Reserves

The mass of water on the Earth's surface is 1.39 * 1018 tons, the bulk of it is contained in the seas and oceans. About sixty of the total reserve are glaciers of Antarctica, Antarctica and highlands (2.4 * 1016 tons), about the same amount of groundwater, but only a small part of them are fresh. Only one ten thousandth part of the total amount is fresh water available for use in rivers, lakes, swamps and reservoirs - 2 * 1014 tons. Another approximately one hundred thousandth part is in the atmosphere - 1.3 * 1013 tons.

Fresh water supplies are unevenly distributed. Nine countries, including Russia, Canada and the United States, but excluding Western Europe, account for 60% of the world's fresh water reserves. According to the definition of the United Nations Economic Commission for Europe, a state is not provided with water, the water resources of which do not exceed 1.5 thousand cubic meters m per inhabitant. In Ukraine, in dry years, 0.67 thousand cubic meters per inhabitant m of river flow. It is the river runoff that makes up the bulk of the total water supply. Even taking into account natural reservoirs, reservoirs and groundwaters, Ukraine belongs to low-income countries by the reserves of water available for use.

What is contained in natural water?

Water, the best natural solvent, is never completely pure. Water dissolves the solids with which it is in contact - soils, rocks, minerals, salts. Atmospheric gases and gases from the depths of the earth dissolve in water, for example, hydrogen sulfide, carbon monoxide, hydrogen, methane. Natural waters, especially surface waters, also contain significant amounts of organic substances - waste products and decomposition of aquatic organisms. Substances of natural origin are added substances of anthropogenic origin, the assortment of which covers almost all classes of inorganic and organic compounds.

The qualitative and quantitative chemical composition of natural waters is very diverse and is determined by physical and geographical conditions. The content of dissolved substances in water is usually expressed in mg / l. In foreign literature, other units are also used:

Ppm (part per million, parts per million) - corresponds to 1 mg / l;
   ppb (part per billion, parts per billion) - corresponds to 1 μg / l or 0.001 mg / l;
   ppt (part per trillion, parts per trillion) - corresponds to 0.001 μg / l.

1. Dissolved gases - oxygen, nitrogen, carbon dioxide, hydrogen sulfide, methane, etc.
2. The main ions (salt components) are the anions of carbonate, bicarbonate, chloride, sulfate; cations of potassium and sodium, magnesium, calcium. In surface waters, their content is expressed in tens and hundreds of mg / L. The combination of these components creates the mineralization of water, measured in g / l. For fresh water, mineralization is 0.2-0.5 g / l, for weakly mineralized - 0.5-1.0 g / l, for brackish - 1-3 g / l. Next come the salt water; waters with a salinity of more than 50 g / l are called brines.

   The presence of cations of calcium and magnesium gives water a combination of properties called water hardness. In our country, water hardness is measured in mmol equiv / l: 1 mmol equiv / l corresponds to 20.04 mg / l of calcium or 12.16 mg / l of magnesium. In other countries, the so-called degrees of hardness are used: German (10 mg of calcium oxide in 1 l of water, corresponding to 0.357 mmol equiv / l); English (1 g of calcium carbonate in 1 gallon, i.e. in 4.546 liters of water, corresponds to 0.285 mmol equiv / l). The smallest degree is American, it corresponds to 0.020 mmol equiv / l.

3. Biogenic elements - nitrogen (in the form of ammonia, ammonium, nitrite, nitrate and nitrogen of organic compounds); phosphorus (in the form of phosphates and organic compounds), silicon (in the form of orthosilicates), iron (II and III). These elements are necessary for the nutrition and development of living organisms. However, some of the compounds at high concentrations have a toxic effect, for example, inorganic nitrogen compounds, especially ammonium nitrogen. For fishery waters, the maximum permissible concentration (MPC) of ammonia is 0.08 mg / l, ammonia - 2 mg / l.
4. Trace elements are metals and some non-metals (bromine, iodine, boron), the content of which in the waters is in the range of several tens or less μg / l. Some metals - manganese, zinc, molybdenum and cobalt belong to the so-called biometals, which are involved in the biochemical processes of living organisms and without which living things cannot develop. Other trace elements, such as cadmium, lead, mercury, chromium are anthropogenic pollutants and exhibit strong toxicity, they are precisely what they mean when talking about heavy metal pollution. Microconcentrations of radionuclides of strontium, cesium, plutonium represent a particular danger to life. However, biometrics, when exceeding the MPC, also have a toxic effect on living organisms. In addition, the toxicity of trace elements depends on what chemical forms they are in. Organometallic compounds, for example diethyl mercury, have the highest toxicity.
5. Organic matter Their content is sometimes characterized by the total content of bound organic carbon. However, such an indicator does not mean much when assessing the degree of pollution of natural waters. Organic substances contained in natural waters should be divided into two groups. The first includes organic compounds of natural origin, mainly humic and fulvic acids, carboxylic and amino acids, carbonyl compounds, esters (the carbon bound in them is 1.5-30 mg / l) and some other compounds with 0.2- 12 mg / l. The second group of organic components of natural waters consists of numerous compounds of anthropogenic origin, the content of which depends on the intensity of water pollution and varies over a very wide range, up to several mg / l. These are aromatic hydrocarbons (benzene, toluene, phenols, naphthalene), halogen-containing compounds (chloroform, dichloroethane, dichlorvos), nitrogen-containing compounds (amines, pyridine, polyacrylamide, urea), methanol, benzyl alcohol, oils, oil products, dyes, synthetic surface-active substances (SAS).

The components of natural waters can be in various aggregate states: in solution in the form of molecules and ions; in the colloidal state - in the form of particles ranging in size from 0.001 μm to 1 μm, invisible during normal observation; in the form of suspensions - larger particles that add turbidity to the water. A significant proportion of trace elements is found in colloidal and suspended particles. Microparticles also include various microorganisms.

Like all environmental objects, natural water is polluted in the process of human economic activity. On December 18, 1962, at the 27th session of the UN General Assembly, a resolution “Economic Development and Nature Conservation” was adopted, which laid the foundation for the environmental movement. Estimates made at that time indicated that there would be enough reserves of clean water and clean air on the planet for three decades. They have already passed, and analysis of the state of water sources leads to the disappointing conclusion that this forecast came true.

Water sources of water supply is usually divided into categories depending on the degree of pollution - from clean water (I class of quality) to polluted (IV class) and dirty (V class). In the 50-60s of the twentieth century, when the currently used water purification technologies were developed, surface sources were assigned to quality class I.

Now, out of 50 water bodies of Ukraine, on which hydrobiological and chemical studies were carried out, there was not one corresponding to the concept of "clean water".

Despite the decline in production, which led to a slight reduction in industrial wastewater, in the Danube, Dniester, Western and Southern Bug and Seversky Donets basins there is an increased content of nitrogen compounds, phenols, oil products, and heavy metals. The water of these sources is classified as polluted and dirty (IV and V quality classes).

The condition of small rivers and natural reservoirs is assessed as catastrophic; groundwater quality is constantly deteriorating. And the technology of water treatment and water treatment has remained virtually unchanged.

Xenobiotics and supertoxicants. Environmental pollution is the reverse side of progress in chemical synthesis. Now the number of chemical compounds created by humans reaches 7 million. About 70 thousand chemical products are used in everyday practice, and their nomenclature is expanding by 500-1000 units per year.

Substances of anthropogenic origin are distinguished by the fact that, in relation to them, the human body (and not only humans) does not have the genetic memory of an appropriate reaction. These are substances alien to living nature - xenobiotics, for them in living organisms by nature there are no ways of processing and elimination. Therefore, xenobiotics tend to accumulate in organisms and distort natural biochemical processes.

The effect of pollutants on the body can be actually toxic and organoleptic. The latter is manifested in the form of an unpleasant odor or taste. Toxic effects can be environmental, carcinogenic, mutagenic, cause occupational or specific diseases.

Among the many pollutants, supertoxicants stand out - substances that even in minimal amounts have a direct or indirect effect on human health. The World Health Organization (WHO) has identified a list of such supertoxicants. This includes, first of all, those substances that were synthesized and produced precisely as poisonous - insecticides, pesticides, zoocides, etc. The other group consists of substances formed as by-products in various processes - fuel combustion, decomposition or synthesis of organic substances, work of automobile engines, etc. Of particular danger are:

• aromatic hydrocarbons (AC) - substances containing a benzene ring;
• polyaromatic hydrocarbons (PAHs) - substances containing condensed benzene rings:

Benzene

• polychlorinated biphenyls (PCDF).

What happens to water during water treatment?

Before supplying water to centralized water supply systems, it is first brought to the condition stipulated by regulatory documents. During water treatment, special chemicals are added to the water.

1. Clarification consists in the removal of coarse and colloidal impurities, causing color and turbidity of the water. For this, coagulants (aluminum or iron sulfates, ferric chloride) and flocculants (polyacrylamide, finely divided silicic acid, etc.) are added to water and precipitated flakes are separated.
2. Water disinfection is necessary for the destruction of pathogens and viruses, as well as certain types of microorganisms (for example, filamentous, zoogley, sulfate-reducing bacteria, iron bacteria), which cause biological fouling and corrosion of pipelines. The most common chlorination of water. Other methods of disinfection include the use of ozone or ultraviolet radiation.
3. Stabilization. Stable is called water, which does not emit and does not dissolve scale, consisting mainly of calcium carbonate. Water dissolving scale causes corrosion of steel and other metals. To stabilize such water, it is treated with alkaline reagents: hydrated lime, soda ash. Water prone to scaling is stabilized by the addition of acids, polyphosphates, treated with carbon dioxide.
4. Water softening involves the removal of hardness salts formed by cations of calcium and magnesium. When reagent softening is used, the above slaked lime and soda ash. Another method of softening is associated with the passage of water through a layer of granular cation exchanger, while the cations of calcium and magnesium are absorbed by the cation exchanger, exchanging for sodium, hydrogen or ammonium ions.

Some types of water require additional operations - iron removal, demineralization, also associated with the use of chemicals.

Some of the reagents used for water treatment (soda, lime, iron compounds) consist of components that were also present in the source water. But in general, it is obvious that at the water treatment plants, the qualitative composition of the water is replenished with new chemical components. Here and the impurities contained in the reagents, and what was formed in the side reactions that accompany the water treatment.

Many of the by-products of chlorination and ozonation are on the list of priority toxicants by WHO. Toxicological studies have shown that they are carcinogenic and (or) adversely affect the reproduction or development of laboratory animals.

Rationing water quality, or what kind of water is called drinking?

Providing the population with high-quality and safe drinking water is a matter of national importance. On January 10, 2002, the Verkhovna Rada of Ukraine adopted the Law on Drinking Water and Drinking Water Supply. It applies to all drinking water suppliers that provide settlements and individual facilities with drinking water through a centralized water supply or through water spills, including mobile ones (remember tankers?).

According to the Law, drinking water is water that, according to its organoleptic properties, chemical and microbiological composition and radiological indicators, meets state standards and sanitary legislation. In Ukraine, the state standard that existed in the USSR (GOST) 2874-82 “Drinking water. Hygiene requirements and quality control. ” The standard normalizes microbiological, toxicological and organoleptic indicators of drinking water at a safe level. The indicators of the last two groups relate to the chemical composition and include standards for substances:

• found in natural waters;
• added to water during processing in the form of reagents;
• emerging as a result of industrial, domestic, agricultural pollution of water sources.

The harmlessness of the chemical composition of water is characterized by toxicological indicators. The limits for a number of toxicants in drinking water (mg / l) have been established, for example:

The concentrations of substances affecting the organoleptic properties of water are also normalized, for example, according to GOST 2874-82, should not exceed the following standards:

The dry residue characterizing the presence of mineral salts and non-volatile substances in water should not exceed 1 g / l; therefore, drinking water that meets regulatory standards can be classified as low mineralized.

The organoleptic properties of water are expressed by indicators of smell, taste, color and turbidity, which are also normalized by GOST.

How do these standards relate to the actual quality and safety of tap water? Three types of situations can be distinguished here.

Situation 1. The water supplied by Vodokanals does not comply with the regulations. According to the chief state sanitary doctor of the Russian Federation G. G. Onishchenko (Ecology and Life, 1999, 4), in Russia as a whole, 20.6% of the samples taken from the water supply do not meet the hygienic requirements for drinking water in terms of sanitary and chemical indicators and 10.6% microbiological. In Ukraine, in 2000, in samples taken from the water supply system, the deviation of the water composition from the current standards averaged about 12%. At the same time, in some areas, for example, Lugansk, only 10% of drinking water sources comply with the standards.

Situation 2. The water supplied to the centralized water supply systems is in compliance with the standards, but not reached the consumer. An additional source of pollution are water pipes. Most often, the low quality of tap water is associated with an increased content of iron and manganese in it. The concentration of iron increases due to corrosion of steel and cast-iron water pipes. Soft water contributes to corrosion. According to the regional bodies of the Sanitary and Epidemiological Service of Russia, about 50 million people, that is, a third of the country's population, drink water with a high iron content.

During operation, water pipes are coated inside with plaque, sediment, consisting mainly of mineral salts. This precipitate serves as a kind of “accumulator” of all kinds of impurities: it absorbs them when polluted water flows through the pipes, and releases it when more pure water is supplied to the pipes. Those who had to be present when replacing water pipes could see on the surface of such a sediment a mucous layer similar to silt. It contains microorganisms - algae, bacteria, viruses that multiply in the enclosed space of water pipes. The presence of some of them in tap water, as well as the pathogenic effect of others, became known relatively recently. The US Environmental Protection Agency, by raising the requirements for the safety of drinking water, expects to supplement the new standards with 36 pollutant control rules, divided into three lists. List 3 is made up of pollutants recently identified in drinking water: algae and toxins; Echoviruses; Coxsackieviruses; Helicobacter pylori; Microsporidia; Caliciviruses; Adenoviruses. Of course, it is advisable to control them not at the water treatment station, but at the place of consumption. Analytical methods for them are still at an early stage of development.

Situation 3. Both supplied by Vodokanal and piped water reached the consumer comply with GOST standards. Does this mean that it is really clean enough to drink and harmless to health? The current GOST provides for the control of 10 toxicological and 9 organoleptic indicators, but among the normalized toxicity indicators, the content of only one organic substance is mentioned - residual polyacrylamide, used to clarify water during water treatment. GOST does not provide for the definition of other organic substances related to toxicants and supertoxicants. Even the control of by-products of chlorination of water is not even provided. But for drinking water there are MPCs for petroleum products, surfactants, phenols, 6 aliphatic and 23 cyclic hydrocarbons (this class includes the super toxicant benz (a) pyrene), 78 halogen-containing compounds and MPCs for more than six hundred different organic substances.

For the introduction of the new standard, a “transition period" from 2000 to 2005 has been allocated. State control over water quality is assigned to the sanitary and epidemiological service laboratory. However, neither they, nor Vodokanals now have the material base to work in accordance with SanPiN, and its formation in the current economic conditions is very problematic. The fact is that water analysis according to GOST 2874-82 standards was carried out using the most affordable instruments - photocolorimeters, pH meters, or chemical methods that did not require special equipment at all. Organic pollutants by these methods are either impossible or very difficult to determine. For modern control of the composition of water, more sensitive and selective methods of analysis are needed that distinguish between substances of similar structure, but of different toxicity and which allow determining low and very low concentrations of pollutants - at the MPC level. One method that meets these requirements is chromatography. Unfortunately, the chromatographic instruments themselves and their maintenance during operation are very expensive.

Only when in Ukraine there are funds to equip all laboratories carrying out the current mass analysis of water with similar equipment, more objective information will appear about what flows from the water tap. This information is needed not only by the consumer; any projects in the field of ecology, water resources rehabilitation, modernization of water supply enterprises should be based on reliable data on the chemical composition of water.

What water is drunk in Western Europe and North America?

In Western Europe and North America, a different culture of drinking water consumption has developed.

Residents of Western Europe were the first to replace tap water with bottles of natural natural water, the first to use home-based water purification systems on a massive scale.

Then these products appeared in the USA, about ten years ago - in Russia and Ukraine.

According to foreign data, in Europe the consumption of bottled water is 100 liters per person per year, in the USA - 43 liters, in Canada - 20 liters, in Russia so far less than 1 liter, but the consumption growth rate is one of the highest in the world.

Why did Western Europe stop counting drinking tap water before everyone else? In densely populated Western Europe, fresh water supplies are limited (as in Ukraine). Here, rivers and lakes, earlier and stronger than in North America, experienced the consequences of intensive economic activity and lost their purity. The greater pollution of surface waters in Europe compared with North America is illustrated by data on the content of carbon tetrachloride, one of the priority pollutants in the waters of these regions (it is used as a solvent in the chemical industry and for dry cleaning):

In Europe (Germany, 1976), the highest level of single pollution of river water with carbon tetrachloride was also recorded: from 160 to 1500 mg / l in the Rhine river, on average 75 mg / l in the Main river.

Residents of Western Europe were the first to feel and realize that the water supply is limited, and the more water they use, the more difficult and expensive it is to process it. It is more reasonable to pour water from clean sources into bottles rather than serve in a water supply system.

In the United States, tap water is considered potable. Its quality is protected by the federal law "On the Safety of Drinking Water", the 25th anniversary of which was very widely celebrated in the USA in 1999 by the President, lawmakers, public organizations recognized the effectiveness of the law, its positive impact on the health of the nation. According to this law, city authorities are obliged to inform the public about the quality of centralized water supply, for example, by posting it on the Internet on the municipal website. So, fans of the television series "Santa Barbara" can go to the website www.ci.santa-barbara.ca.us and find out about the quality of the water supplied to the homes of their favorite television heroes. The information reports on the state of the city’s drinking water sources and on the content of substances controlled at the water treatment plant, in the distribution system and in the consumer water supply system. In the distribution system, mainly by-products of water chlorination are controlled.

In the United States, bottled water (mainly imported from Europe) is also quickly becoming popular as the main alternative drink, like soft drinks or iced tea. But here, a water bottle does not replace a water supply system, rather, it is a convenient form of transportation: most of the bottled water is consumed in machines. Municipal information convinces the public that tap water is completely safe to drink and does not need to be replaced with bottled water. Moreover, about 25% of bottled water sold in the USA is municipal tap water, sometimes filtered, sometimes not.

In 2001, the magazine “Drinking Water” began to appear in Russia. The editorial staff of the magazine, discussing the availability of information on the quality of tap water in the United States, expressed its readiness to post on its pages the information of Vodokanals on the quality of the supplied water. The editors also recommend that such information be posted on the Internet, for example, on the corporate website of Vodokanals, which was created in St. Petersburg - http://www.waterandecology.ru/vodokanal. This call has not yet been heard. Among the others, one Ukrainian Vodokanal is also represented on the site - Lutsk.

Features of post-treatment of tap water

For additional purification, water is passed through filters, distilled to obtain distilled water, or treated with sorbents (solids that absorb dissolved impurities).

What should be remembered when using such water for drinking?

Distilled water may contain organochlorines - by-products of the chlorination of water. They are volatile and are distilled off during distillation and then condensed together with water vapor. The content of volatile chlororganic substances in distilled water (as well as tap water) decreases upon boiling or settling. Distilled water contains a noticeable amount of copper compounds because the internal parts of distillation plants are usually brass.

Cleaning on filters is effective until the filter has exhausted its resource, in other words, it is not clogged. Here, the consumer has to rely on the instructions on the resource of the filter manufacturers, as well as on the fact that the treated water is not dirtier than the one on which this resource was installed. It is known that the filter life can vary by tens of times depending on the composition of the water being treated; In addition, different manufacturers have different methods for assessing the resource, which makes it difficult to compare different water treatment devices for efficiency.

When using natural sorbents, such as clays, the question arises of the chemical and bacteriological purity of the sorbent itself.

In all cases, the purified water contains less dissolved substances. Along with pollutants, substances of natural origin, in particular, useful minerals and trace elements, are also removed from the water. Therefore, some Western European, and now domestic consumers, consider the main disadvantage of treated water is that when it is used regularly, the body loses valuable nutrients. However, drinking water has never been and is not the main source of minerals or trace elements necessary for the body. Perhaps the greatest is the contribution of drinking water to providing the body with fluoride - up to half the daily requirement. The need for other elements or trace elements is mainly provided, of course, by food; To do this, one would have to drink too much. This is demonstrated by the following data:

Element	The average daily requirement of an adult, mg	Concentration in water, mg / l	The amount of water containing the daily norm of the element, l	The amount of food containing the daily rate of the element
Calcium				80 g of cheese or 670 g of milk
Phosphorus				240 g of cheese or 343 g of oatmeal or 480 g of fish
Magnesium				223 g of watermelon or 250 g of buckwheat or 343 g of oatmeal
Iron				75 g of pork liver or 220 g of buckwheat or 250 g of beans or 750 g of apricots
Copper				00 g pork liver or 460 g buckwheat or 1 kg of rye bread
Other    micro elements

Brief Summary

There are good reasons to believe that the quality of domestic tap water has deteriorated over the past 30–40 years. The pollution of water supply sources has increased significantly, the range of toxic pollutants has increased, and the technologies for centralized water treatment have remained almost the same, designed for clean water sources. Worn pipes further contaminate tap water. The safety of the use of tap water could be convinced by operational, accessible to the ordinary consumer information on the quality of the supplied water. But complete information that would be consistent with international experience in monitoring the quality of drinking water is not available to the water suppliers themselves.

Perhaps, in the coming years, no significant changes can be expected either in the quality of domestic water treatment or in the awareness of the population about the quality and safety of tap water. The choice of alternative methods of water consumption remains with the consumer.

Literature

1. Chemical Encyclopedia: In 5 vols. - M.: Sov. encycl., 1988. - T. 1–623 c ;. - M .: Owls. encycl., 1990. - T. 2. - 671 c;
2. Water is nutritious. Normative documents: Dovidnik: U 2 t. - Lviv: STC “Leonorm-format”, 2001. - T.1. - 260 s .; T.2. - 234 p.
3. Control of chemical and biological environmental parameters. St. Petersburg, Environmental and Analytical Information Center "Union", 1998. - 896 p.
4. Analytical chemistry of natural remedies / B. Y. Nabivanets, V.V. Sukhan, L.V. Kalabina and іn. - K .: Libid, 1996 .-- 304 p.
5. WHO Carbon Tetrachloride. Environmental Health Criteria No. 208. World Health

L.P. Loginova.All-Ukrainian popular science magazine “UNIVERSITATES. Science and enlightenment "

Mineral water is underground (rarely surface) water that contains in high concentrations biologically active mineral and organic components, which has specific physicochemical properties that have a therapeutic effect on the human body. Depending on these properties and composition, it can be used both as an external and as an internal therapeutic agent.

Medicinal mineral waters are called natural waters, which contain large quantities of certain mineral substances, various gases (carbon dioxide, hydrogen sulfide, nitrogen, and others) or possess unique properties - radioactivity, temperature, and so on.

The process of formation of mineral waters is very complex and still not well understood. Rainwater seeping through the rocks, for centuries accumulated in different layers of the earth's crust. All this time, numerous mineral substances were dissolved in it, and the deeper it penetrated into the earth's crust, the more it was purified, and the more carbon dioxide and useful substances accumulated in it.

Depending on what layers the water passed through, at what depth it lies and how old it is, we get various types of its healing properties. Mineral waters come to the surface in the form of natural mineral springs or are discharged using boreholes.

The chemical composition of mineral water

The chemical composition of mineral water is determined by the salts dissolved in it. They are represented by electrically charged particles - ions with a positive or negative charge. The main ones are: three cations - sodium (Na +), calcium (Ca 2+), magnesium (Mg 2+) and three anions - chlorine (Cl), sulfate (SO 2) and bicarbonate (HCO 3). In small quantities in mineral water contains almost the entire periodic table.

Carbon dioxide is also an important component of mineral water, since due to the interaction of carbon dioxide with underground rocks, the healing properties of water are formed.

CLASSIFICATION OF MINERAL WATERS

The main indicators on which the classification of mineral waters is based are: mineralization, ionic composition, gas composition, temperature, acidity (alkalinity), radioactivity.

Classification of mineral waters by mineralization.
  Mineralization, i.e., the sum of all water-soluble substances - ions, biologically active elements (excluding gases), is expressed in grams per 1 liter of water. Distinguish: weakly mineralized mineral water (1 - 2 g / l), low (2 - 5 g / l), medium (5 - 15 g / l), high (15 - 30 g / l) mineralization, brine mineral water (35 -150 g / l) and hard brine (150 g / l and above).

Classification of mineral waters in terms of balneology.
  Depending on the degree of mineralization, the mineral waters used for drinking treatment are divided into:
  a) canteens - mineralization up to 1 g / l;
  b) medical and canteens - mineralization from 1 to 10 g / l;
  c) therapeutic - mineralization of more than 10 g / l or a high content of biologically active elements: iron, bromine, iodine, hydrogen sulfide, fluorine, etc., while the total mineralization can be low.

Table mineral water stimulates digestion and does not have medicinal properties. It can be drunk in any quantities. As a rule, it is soft, pleasant to the taste, without foreign smell and taste, many soft drinks are made on its basis.

You cannot cook food in table water. When boiling, mineral salts precipitate or form compounds that are not absorbed by the body.

Medical-table mineral water is drunk both for prevention and as a dining room. But it has a pronounced therapeutic effect only with proper use. When used in unlimited quantities, the salt balance in the body can be disturbed.

Healing mineral waters are used for drinking treatment and for external use - baths, showers, baths, as well as for inhalations. The effect of its use depends on the correct choice of the type of water and on the correct intake - dose, frequency, temperature, food regimen. Therefore, it is necessary to carry out treatment with mineral water under the supervision of a doctor.

Classification of mineral waters by chemical composition:
  a) hydrocarbonate;
  b) chloride;
  c) sulfate;
  g) sodium;
  e) calcium;
  e) magnesium;
  i) mixed.

Bicarbonate mineral water - contains bicarbonates (mineral salts), more than 600 mg per liter. It reduces the acidity of gastric juice. Often used as a remedy for heartburn. It is used in the treatment of urolithiasis. It is recommended for people who are actively involved in sports, infants and patients with cystitis.

Mineral chloride water contains more than 200 mg of chloride per liter. It stimulates metabolic processes in the body, improves the secretion of the stomach, pancreas, small intestine. It is used for disorders of the digestive system. Contraindicated in high blood pressure.

Sulphate mineral water - contains more than 200 mg of sulphates per liter. It stimulates gastrointestinal motility and has a beneficial effect on the restoration of liver and gall bladder function. It has a mild laxative effect, removes harmful substances and impurities from the body. It is used for diseases of the biliary tract, chronic hepatitis, diabetes mellitus, obesity. Sulphate water is not recommended for children and adolescents: sulphates can interfere with calcium absorption.

Sodium, calcium, and magnesium mineral waters are waters with a predominance of Na +, Ca 2+, and Mg 2+ cations, respectively.

Most mineral waters have a complex mixed structure: chloride-sulfate, hydrocarbonate-sulfate, etc. This increases their therapeutic effect.

Classification of mineral waters depending on the gas composition and the presence of specific elements:
  a) carbonic (acidic);
  b) sulfide (hydrogen sulfide);
  c) bromide;
  g) iodine;
  e) arsenic;
  e) glandular;
  i) silicon;
  j) radioactive (radon).

Classification of mineral waters according to temperature: very cold (below 4 ° C), cold - up to 20 ° C, cool - up to 34 ° C, indifferent - up to 37 ° C, warm - up to 39 ° C, hot, or thermal - up to 42 ° С and overheated, or high-temperature - over 42 ° С.

Classification of mineral waters depending on acidity: neutral pH 6.8 - 7.2; slightly acidic pH 5.5 - 6.8; acidic 3.5 to 5.5; strongly acidic - 3.5 and less; slightly alkaline 7.2 - 8.5; alkaline - 8.5 or more.

CHARACTERISTICS OF POPULAR MINERAL WATERS

The mineral waters of Essentuki are extracted from a depth of 1.5 km and have many different types. All sources are located on the territory of the specially protected ecological-resort region of the Caucasian Mineral Waters. Mineral water, poured in a mineral water factory into environmentally friendly glass containers, is certified and complies with the WHO requirements (Geneva 1986) for medicinal table and drinking water.

Essentuki No. 4 - medical-table mineral water has no analogues in its healing and taste properties. This is a carbonic sodium bicarbonate-chloride mineral water of moderate concentration. It is used for diseases of the gastrointestinal tract, liver, kidneys, and bladder. It has a complex effect on various functional systems of the body.

Essentuki No. 17 is the most famous healing mineral water in Russia. It is a carbonic sodium bicarbonate-chloride water. It has a significant concentration of mineral substances. Mineralization 11-14 g / l. It is used for the same diseases as essentuki No. 4, often in combination with it. Essentuki No. 17 has many contraindications for use, so its independent appointment is unacceptable.

Essentuki № 20 table low-mineralized mineral water. It belongs to the type of sulphate-bicarbonate-calcium-magnesium water of low concentration. Its value lies in the fact that it is pure from nature and is not subjected to additional purification using chemical reagents. Favorably affects intestinal function and promotes normal digestion. This is not only table water, but also an effective therapeutic agent that works wonderfully in diseases of the metabolism and urinary tract.

Narzan is a carbonic hydrocarbonate-sulfate-calcium water of the source of Narzan in Kislovodsk. Mineral water "Narzan" has gained worldwide fame as one of the most valuable medicinal-table waters. Mineralization 2 - 3 g / l. It quenches thirst well, slightly tones and increases appetite. Narzan enhances intestinal motility and secretory activity of the digestive glands, increases the amount of urine, and helps dissolve phosphates. The salts of magnesium sulfate and calcium bicarbonate contained in narzan have a beneficial effect on the body with catarrhal diseases of the urinary tract.

Borjomi - carbonic sodium bicarbonate water. Its source is located in Georgia, on the territory of the resort of the same name, at an altitude of 800 m above sea level. This mineral water is world famous. Its mineralization is 5.5 - 7.5 g / l. It belongs to the group of medicinal-table waters and is successfully used in the treatment of gastrointestinal diseases, liver diseases, urinary tract infections, metabolic disorders.

Mineral water Naftusya (Truskavetskaya) - slightly mineralized bicarbonate calcium-magnesium water. It is used to treat the urinary tract, urolithiasis, and stimulates bile formation.

Smirnovskaya - carbonic hydrocarbonate-sulfate-iatrium-calcium water Zheleznovodsk hot spring. It is very effective in the treatment of peptic ulcer of the stomach and duodenum, it also has a beneficial effect in the treatment of the liver, bile and urinary tract.

"Slavyanovskaya". It is obtained in the resort of Zheleznovodsk. Mineralization 3-4 g / l. Useful in the treatment of diseases of the gastrointestinal tract. The low mineralization and the presence of calcium bicarbonate make it also an effective treatment for kidney and urinary tract diseases.

THERAPEUTIC ACTIVITY OF MINERAL WATERS

The healing effect of mineral water depends on its chemical composition, temperature, the presence of minerals and gases. It has a therapeutic effect on the human body with the whole complex of substances dissolved in it. The choice of water for treatment, as well as the frequency of administration, its amount and temperature, is made individually by the doctor.

Mineral waters with a high content of bicarbonate ions (alkaline waters) effectively affect the gastrointestinal tract. They are effective for gastritis, colitis and pancreatitis, peptic ulcer disease and diabetes.

Ferrous mineral waters have a therapeutic effect on the circulatory system, as they promote the formation of red blood cells and increase hemoglobin in the blood. They effectively help with anemia.

Mineral waters with a high iodine content stimulate the activation of metabolic processes, have a calming effect on the nervous system, and positively affect the activity of the thyroid gland.

Siliceous waters soothe and have an anti-inflammatory effect. They are especially useful for older people with diseases of the gastrointestinal tract.

Potassium - strengthens the heart, improves kidney function. Calcium - strengthens bones, muscles, teeth, is useful for the cardiovascular system, establishes ionic balance in the body, has a beneficial effect on blood coagulation. Magnesium - regulates carbohydrate and energy metabolism, helps the nervous system.

Baths with mineral waters have a beneficial effect on the human body, increase its defenses. In therapeutic baths, gas, radioactive, chloride and other waters are used. Each of these baths has individual healing properties and is indicated for certain diseases.

Sulfide (hydrogen sulfide) baths improve heart function, have healing, anti-inflammatory, absorbable and analgesic properties. They are indicated for diseases of the skin, musculoskeletal system, cardiovascular and nervous systems.

Radioactive (radon) baths provide a fairly strong therapeutic effect for dermatoses, psoriasis and other skin diseases, have a sedative and analgesic effect.

Rules for the use of mineral waters

Before using bottled mineral water, you should remove the preservative - carbon dioxide. To do this, open the bottle should be lowered into a container of warm water for 15 to 20 minutes. Heated mineral water leads to the release of excess carbon dioxide.

Drink mineral water should be slowly, slowly, in small sips. Weakly mineralized waters are recommended to be taken in a larger dosage compared to highly mineralized ones. How much and what water should be taken is decided by the attending physician.

The course of drinking treatment is usually not more than 1 month. After a break of 2 to 3 months, it can be repeated.

In chronic gastritis and gastric ulcer, cholecystitis, gallstone disease, intestinal cramps and diarrhea, you need to drink hot water.
  With increased secretion and acidity of the gastric juice, water should be drunk heated.
  For constipation, cold mineral water should be taken.
  Attention. In diseases of the liver and gall bladder, cold water should not be drunk.

It is most often recommended to take mineral water on an empty stomach, but for some diseases, such as diarrhea, drinking water on an empty stomach is not recommended.
  With increased acidity of the gastric juice, water should be drunk 1-1.5 hours before a meal.
  To activate the digestive glands, mineral water should be taken 15 to 20 minutes before a meal.
  With heartburn and pain in the stomach, you should drink alkaline waters of Essentuki, Borjomi after eating 0.25 - 0.3 cups every 15 minutes.
  With increased secretion of gastric juice, water can be taken with food.

Mineral water treatment is incompatible with alcohol. Smoking should also be avoided, since nicotine is a potent irritant, its effect is the opposite of the action of healing water.

Quality mineral

According to international standards, natural mineral water must meet the following requirements:
  - come from a natural source, protected from any pollution, and pour directly into bottles at a distance of not more than 50 m from the source;
  - come only from officially registered sources;
  - mined only by an officially recognized method;
  - maintain natural purity.
  It is forbidden to use any methods that can change the original, natural properties of mineral waters.
  The use of filters is allowed only for cleaning from mechanical impurities and, in some cases, from undesirable substances (for example, iron or sulfur compounds).
  If water is taken from a source saturated with carbon dioxide, then it can be partially removed.

To distinguish mineral water from drinking water, you need to focus on GOST or TU. The inscription GOST 13273-88 indicates that it is natural mineral water. Also on the label may be the inscription TU 9185 (further figures are not so important) and the number of the well or the name of the source is indicated. This is also natural mineral water, its composition in the bowels and in the bottle is the same. TU 0131 says that it is not mineral, but drinking water.

Real mineral water, as a rule, contains a label with detailed information about the manufacturer, its location, terms and conditions of storage, well number, as well as the time and date of storage. The labels may even indicate a list of diseases in which this category of water is indicated. Also, the logo of the company may be present on the container or lid.

Storage

Mineral water bottles must be stored horizontally at a temperature of + 4 ° C to + 14 ° C. Separate rust spots on the outer surface of the metal cover are allowed, which do not violate the tightness of the closure.

The shelf life of mineral waters (except ferruginous) in a glass container, subject to the specified conditions, is 1 year from the day of bottling. During this period, mineral waters retain their composition and have the same biological and therapeutic effect on the human body as they are taken directly from the source.

"Water" topics are increasingly heard in the Russian press, and often arguments are given about the advantages or disadvantages of water from the point of view of supplying the body with useful minerals. Some materials published in reputable publications quite peremptorily stated: "As you know, with water we get up to 25% of the daily requirement of chemicals." Moreover, this figure wanders over different publications. However, in the conversations of specialists, the figure is more than 6-8% with reference to WHO (World Health Organization). However, neither in the first nor in the second case did we manage to get to the source. And we decided ourselves to look for the answer to the question: "How much can an average person get minerals from drinking water that meets sanitary standards?" In our reasoning, we were guided by simple everyday common sense and knowledge in the volume of high school. The results we have tabulated. Let us explain the contents of its columns, and at the same time the course of our reasoning.

First you need to decide on several starting positions:

1. What minerals and in what quantities do people need?

First a short digression.

The question of the "mineral composition" of a person and, accordingly, the needs of his body is very complex, one of the fundamental and even philosophical ones (we recommend looking especially inquisitively at the article "Biogenic classification of chemical elements" from the journal "Philosophy of Science"). At the household level, we very easily juggle (unfortunately in the mass media too) the terms “useful elements”, harmful or toxic “elements”, etc. To begin with, the very formulation of the question of the harmfulness-usefulness of chemical elements is the fruit of human majesty mania. The chemical elements are what they are. They were so millions and billions of years ago and will remain so even when there will be not only humanity, but also our entire planet. In other words, what is beneficial to bacteria can be harmful to humans and no one has yet proved that from the point of view of Nature, humans are more important than bacteria. If you still talk about concepts such as "harmfulness" and "utility", then back in antiquity it was known that the whole thing is in concentration. What is useful in minimal quantities may be the strongest poison in large quantities.

But "back to our sheep."

We limited ourselves to a list of the main "essential" (vital) macrocells and several microelements. The list is given in the 1st column.

As the norms of daily needs, we used the data provided in the Popular Medical Encyclopedia. Moreover, for the base we took the minimum value for an adult man (for adolescents and women, especially nursing mothers, these standards are often higher). The indicators are given in the 2nd column.

  2. What is the mineral composition of "medium" water?

It is clear that there is no “average” water and cannot be, therefore it is necessary to “invent” it. As such, we propose using hypothetical water in which the concentration of the elements is consistent with WHO recommendations. This is done because according to the WHO, it is such an extreme content of each of the elements in water that makes its daily use safe for health. In those cases where the relevant WHO standards are not established, we were guided by the norms of the Russian SanPiN "Drinking Water", or, if this parameter is not standardized by Russian standards, then respectively by EU or US standards (see the section "Inorganic Impurities"). The only exception was iodine, where the maximum concentration in natural fresh waters was taken as the limiting concentration. It should be noted that the concentration of some elements (for example phosphorus) was obtained by recalculation from the norms for more chemically complex elements (in this case, phosphates). The fact is that elemental phosphorus is the strongest poison and its MPC (maximum permissible concentration) for drinking water is very small.

Thus, we took some kind of water as consumed, in which the content of the main bio-elements is equal to the maximum acceptable from the point of view of safety for health (3rd column of the table). There probably is no point in saying that in reality the content of most elements in water is much lower than the MPC. We also leave out the brackets of our discussion the rhetorical question whether it is possible with a calm soul to constantly consume water in which a good dozen parameters are at the ultimate level. On the contrary, we will consider that such water is “most useful” in its mineral composition.

Based on these data, it was calculated how much water should be consumed in order to gain a daily rate for each element (4th column of the table). The huge assumption here is that in the calculations we took the digestibility of minerals from water as 100%, which is far from true.

3. What is the daily water consumption of the average person.

We have already answered this question in the section "Drinking regimen and water balance in the body." A day, directly in the form of a liquid (drink and liquid food), a person consumes 1.2 liters of water. It is this figure that formed the basis for calculating the percentage of water intake of each element, which theoretically (taking into account all the above assumptions) can be received by an average person per day. The figure is obtained by dividing 1.2 by the corresponding value from the 4th column.

As a result, we calculated the weighted average percentage of human production of macro- and microelements that water can provide.

In order not to be accused of fraud, we give the calculation in full:

800x15 + 1200x0.12 + 500x12 + 2000x0.72 + 5000x4.8 + 2000x15 + 1000x10 + 10x3.6 + 2x90 + 2x60 + 0.1x89
800 + 1200 + 500 + 2000 + 5000 + 2000 + 1000 + 10 + 2 + 2 + 0,1

That is, even theoretically, water cannot provide the intake of more than 6.7% of the minerals needed by humans.

!!! .!!!

Of course, we in no way pretend to the absolute scientific nature of our conclusions. Moreover, we assume that 10-15% percent were mistaken in a smaller direction. In any case, this just gives those 6-8%, which is rumored by WHO. Moreover, we note that these figures are most likely theoretically possible. In practice, given the real content of macro- and microelements in water, this figure can be reduced by 1.5 - 2 times.

As a matter of fact, even spending a lot of time and studying a lot of materials related to macro- and microelements, you can find only one element - fluorine, about which it is directly indicated that the source of its entry into the body is water. All the others are clearly stated that their source is food.

That is why, for comparison, we provide in the 6th column a mini-list of alternative (food) sources of intake of the same elements. The content of the corresponding element in this product is indicated in parentheses (1 mg% corresponds to the content of the element in milligrams per 100 grams of product). We used a list of several products to illustrate the fact that the body receives one or another macro- or microelement not at the expense of one product, but usually from a little of the different ones.

Column 7 shows the amount of a particular product in grams, the use of which will give the body a day (with the same assumption of 100% digestibility as for water) the same amount of the corresponding macro- or microelement as our hypothetical water (see . above item 2).

Of course the data given in no way serve as nutritional recommendations. This is the whole science of dietetics. This table is intended only to illustrate the fact that it is much easier to obtain macro- and microelements necessary for the body and, most importantly, more real from food than from water.

Element	Daily requirement	MPC    in water	The required amount of water to obtain 100% normal	Theoretically possible % min. substances from water	Alternative source	Amount of product, which makes it possible to obtain bioelements equal to that obtained with water
1
Calcium					Hard cheese (1005 mg%)    Brynza (550 mg%)    Parsley green (245 mg%)    Curd (160 mg%)    Dried apricots (160 mg%)    Beans (150 mg%)    Milk (120 mg%)	12 g    24 g    49 g    75 g    75 g    80 g    667 g
Phosphorus					Dried mushrooms (606 mg%)    Beans (540 mg%)    Hard cheese (500 mg%)    Oatmeal (350 mg%)    Liver (320 mg%)    Fish (250 mg%)    Beef (188 mg%)    Rye bread (158 mg%)	24 g    36 g    29 g    41 g    45 g    58 g    77 g    91 g
Magnesium					Watermelon (224 mg%)    Nuts (200 mg%)    Buckwheat groats (200 mg%)    Oatmeal (116 mg%)    Peas (107 mg%)    Corn (107 mg%)    Millet bread. 2 grade (89 mg%)    Hard cheese (50 mg%)	27 g    30 g    30 g    52 g    56 g    56 g    68 g    120 g
Potassium					Dried apricots (1717 mg%)    Beans (1100 mg%)    Seaweed (970 mg%)    Peas (873 mg%)    Peanuts (732 mg%)    Potato (568 mg%)    Radish (357 mg%)    Tomatoes (290 mg%)    Beetroot (288 mg%)    Apple (278 mg%)	0.86 g    1.31 g    1.44 g    1.66 g    1.87 g    2.53 g    4.03 g    4.97 g    5.00 g    5.18 g
Sodium					Food salt (38710 mg%)    Soft cheese (1900 mg%)    Sheep feta cheese (1600 mg%)    Sauerkraut. (930 mg%)    Cucumber salt. (900 mg%)    Rye bread (610 mg%)    Shrimp (540 mg%)    Seaweed 520    Flounder (200)	0.6 g    13 g    15 g    26 g    27 g    39 g    45 g    46 g    120 g
Chlorine