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How much does it cost to buy a diploma in Ukraine? Lead in water Regions with high levels of lead in water

In the Ryazan region, 20 out of 25 existing districts were noted where the maximum permissible concentration of harmful chemical elements was exceeded. The cleanest water, according to the compilers of the map, flows in the south of our region - in the Alexander Nevsky, Sapozhkovsky, Sarajevo, Ukholovsky and Pronsky districts.

"Iron" Ryazan residents

In Ryazan, water samples showed the presence of microbes that can cause acute intestinal infections.

This may be due to fecal contamination, such as sewage discharge into the water, or other reasons that lead to the water becoming contaminated with microbes, the researchers note.

The concentration of iron in Ryazan water is also almost 5 times higher (1.4350 mg/l). “Iron” water increases the risk of developing diseases of the digestive system, blood, and skin among Ryazan residents, decreased immunity, and hair loss.

To disinfect water from germs, experts recommend drinking only boiled water. For cleaning, it is also recommended to use a filter jug ​​with a special cartridge to remove bacteria (with 100% protection), a filter system with a separate tap based on reverse osmosis or ultrafiltration. It is important that the packaging of the filter or replacement cartridge must have a special mark “100% protection against bacteria”, or “Reverse osmosis filter”, or “The filter uses the ultrafiltration method”.

Boron, fluorine, lead...

In the Zakharovsky district, the water also contains iron concentrations 3.5 times higher than normal. In the Kasimovsky district, in addition to microbial contamination, the concentration of lead in the water is almost 4 times higher. In Kasimov itself, water can cause acute intestinal infections due to unsatisfactory bacteriological tests. The presence of harmful bacteria in water also increases the risk of developing diseases of the digestive system. Bacteriological water samples in the Miloslavsky district were significantly exceeded. Microbial water pollution is also present in the Pitelinsky district.

In the Rybnovsky district, in addition to microbial water pollution, an excess of the maximum permissible concentrations of iron was found by 4 times, fluorine by 2 times, lead by 1.5 times, boron by 1.16 times. In addition, water hardness is more than 10 mg/eq/l with a standard value of 7 mg/eq/l. All this threatens infertility and intrauterine deformities in the fetus, cancer, the development of diseases of the digestive system, blood, nervous and endocrine systems, kidneys, teeth and bones, skin, reduces immunity and promotes hair loss.

In the Ryazan region, in addition to microbial pollution, the iron content in water was 5 times higher and the fluorine content was 2 times higher.

In Skopin, in addition to microbial contamination, the water contains almost 5 times more iron and 1.15 times more lead. Lead concentrations also 5 times higher than normal were found in the water of the Starozhilovsky district. Slightly less lead was found in the water of the Skopinsky district (1.11 times), where microbes and iron were also higher than normal (1.16 times higher than normal).

In the Spassky region, the maximum permissible concentration of boron and fluorine in water is almost 2 times higher than the norm. The same elements are exceeded in the water of the Chuchkovsky and Shilovsky districts, plus the life-giving moisture there is contaminated with microbes. The boron content in the water of the Shatsk region is 4 times higher, and the fluorine content is 3 times higher. Boron content in the water of the Sasovo district is 2 times higher than the norm, which is also contaminated with microbes. Also 2 times higher than the norm of boron in the water of the Ryazhsky region. In the Putyatinsky district, the iron content in the water was 1.03 times higher. Microbial contamination was detected in the water of the Mikhailovsky district, and the maximum permissible concentration of iron was exceeded 2.5 times. In the Korablinsky district, the maximum permissible concentration of iron (4 times higher than normal) and lead (1.5 times) is exceeded in the water.

In addition to microbial contamination, the water in the Ermishinsky district contains 3.5 times higher levels of boron, 2 times higher levels of fluorine, and 1.61 times higher levels of iron. In the Klepikovsky district, the water is also polluted by microbes, and the maximum permissible concentration of fluorine is exceeded by 2 times, iron by 0.5 times, boron by almost 2 times, and lead by 1.33 times higher than the norm. In addition, the water in this area is highly hard. In the Kadoma region, in addition to microbial contamination, the water content was 4.5 times higher than the boron content and 3 times higher than the iron and fluorine content.

BY THE WAY

A filter system with a separate tap based on reverse osmosis will help reduce the concentration of boron in water. To reduce lead in water, filter jugs, nozzles, and a system with a separate tap are used. The filter packaging must have a special note “Water purification from heavy metals”, or “The filter uses an ion exchange resin”, or “Filter based on ion exchange”.

To soften water, filter jugs with a special cartridge for purifying hard water are used, as well as a filter system with a separate tap equipped to reduce water hardness. The filter packaging should have a special mark “For purifying hard water” or “Reducing water hardness”.

Skin rashes and stains on teeth are the most innocent things that bad tap water can give us. In every region of Russia, tap water has its own disadvantages: it does not hurt citizens to learn more about them.

Text: Ruslan Bazhenov

WITH sulfates

Exceeding the maximum permissible concentration (hereinafter referred to as MPC) of sulfates in drinking water leads to a decrease in the acidity of gastric juice and diarrhea. When the norm is five times higher (MPC - up to 500 mg/l), they accelerate significantly. It is this excess that is typical for tap water in the Rostov, Samara, Kurgan regions and Altai Territory.

In regions with even a twofold excess of sulfates (for example, in Central Asia), the local population gets used to them, while visitors immediately experience “interruptions” in the functioning of the gastrointestinal tract.

Nitrates and nitrites

In the human body, nitrates are reduced to nitrites, and they, in turn, interact with hemoglobin, forming a stable compound - methemoglobin. As you know, hemoglobin carries oxygen, but methemoglobin does not have this ability. As a result, tissues begin to experience oxygen starvation, and a disease develops - nitrate methemoglobinemia. Outbreaks of this disease, mostly among children, have been reported around the world in regions with high levels of nitrates in water. All sick children drank water containing nitrates from 18 to 257 mg/l (in Russia, the maximum permissible concentration for nitrates is 45 mg/l). The content of nitrates in drinking water, three or more times higher than the norm, occurs in the Rostov, Lipetsk, Bryansk, Tula and Voronezh regions.

F torides

For Russia, the problem is exactly the opposite - an excess of fluorine. Studies have shown that when the fluorine content in water is 5-7 mg/l, pronounced osteosclerosis (bone tissue thickening) develops, and at 10-20 mg/l children experience significant

Fluorosis is caused by residents who drink water containing 2 mg/l of fluoride, while the World Health Organization (WHO) recommended level of fluoride in drinking water is 1.5 mg/l. A number of cities and districts of the Moscow, Tver, Penza and Vladimir regions, the Republic of Bashkortostan, Mordovia and the Krasnodar Territory, where the fluoride content in water exceeds the norm, fall into the risk zone. For example, in such cities of the Moscow region as Vidnoye, Podolsk, Yegoryevsk, Odintsovo, Krasnogorsk, fluorosis was detected in 25 percent of the population.

The press, manufacturers of bottled water and fluoride-containing toothpastes willingly exaggerate the alleged problem of lack of fluoride in Russian tap water. But in fact, the amount of fluoride (0.01 mg/l), which, being insufficient, leads to caries, is practically not found in the water sources of our country. This is evidenced by research data from Gorno-Altai State University. To be fair, we would like to add that on the question of how much fluoride is required to prevent caries, the scientific community has not yet reached a consensus.

Iron

Iron in a concentration three times higher than the norm (MPC - 0.3 mg/l) is present in the water supply systems of the Tomsk, Vologda, Tambov, Arkhangelsk, Chelyabinsk, Tver, and Novosibirsk regions. This excess leads to itching, dryness and rashes on the skin; the likelihood of development increases.

Iron of natural origin enters drinking water from underground sources in the central and southern regions of Russia, as well as the Siberian region. In addition, an increased concentration of iron occurs when using steel and cast iron water pipes, which are destroyed due to corrosion. St. Petersburg is especially unfavorable in this regard, where soft water increases corrosion.

Iodine

Sad fact: 65% of the Russian population drinks water with insufficient iodine content. The average iodine consumption in our country is 40-80 micrograms per day per person, which is half the physiological requirement. Lack of iodine leads to the development of Graves' disease, delays in physical and mental health. Water iodization, which they tried to put forward as a countermeasure, turned out to be ineffective, as did iodization of salt.

B rum

The bromine content in the underground springs of the Eastern Trans-Urals exceeds the standards by 40 times (MPC - 0.2 mg/l) - in such concentrations it contributes to the development of pathologies of the cardiovascular system. Analysis of statistical data revealed a direct relationship between the overall mortality rate of the population and the bromine content in drinking water in this region.

M arganese

Manganese is found in a concentration three times higher than the norm (MPC - 0.1 mg/l) in tap water in the Tomsk, Vologda, Tambov, Arkhangelsk, Chelyabinsk, Tver, and Novosibirsk regions. A number of scientific studies have found that such an amount of manganese has a negative effect, has a toxic and mutagenic effect on the human body. The manganese content in drinking water directly depends on the activities of nearby industrial enterprises.

Accumulating in brain tissue, mercury leads to severe nerve damage and contributes to disruption of the cardiovascular system. Even small doses are dangerous: the lower limits of mercury content in drinking water, at which it would not accumulate in the body, have not yet been established. One of the main sources (85%) of mercury in the environment is the activity of industrial enterprises. Exceeding hygienic standards was revealed in the Belgorod and Vologda regions. However, the natural high content of mercury in the water of some regions, for example in the Altai Mountains, also plays a role.

Lead

Lead is most dangerous for children and pregnant women. In children, it reduces IQ and provokes the development of heart defects. In women, it increases toxicosis and the birth of children with developmental defects, and in addition, leads to infertility.

Exceeding the maximum permissible concentration (norm - 0.03 mg/l) of lead is observed in drinking water in the Kaluga and Ryazan regions. The main source of lead in tap water is the destruction of lead-containing elements of water supply networks (solders, brass alloys).

And aluminum

Has a significant neurotoxic effect causing early onset. In addition, aluminum leaches calcium from the body, which is especially dangerous for a growing body. Exceeding the MPC of aluminum (norm - 0.5 mg/l) was recorded in drinking water in the Arkhangelsk, Samara and Omsk regions. The main source of aluminum in tap water are substances used during water treatment at treatment plants - coagulants.

X loroform

American researchers have established a direct relationship between the content of chloroform in drinking water and the increase in the number of cancer diseases.

During the chlorination of tap water, chloroform is formed, and in fairly high concentrations. WHO sets the maximum permissible concentration for chloroform at 0.03 mg/l, which, according to many researchers, is an outrageous underestimation of the danger of this substance. But the situation is even worse in Russia, where the maximum permissible concentration for chloroform is many times higher than WHO standards - 0.2 mg/l!

Exceeding the maximum permissible concentration of organochlorine compounds was recorded in drinking water in the Kemerovo, Nizhny Novgorod, Perm, Sverdlovsk regions, and St. Petersburg.

P surfactants (surfactants)

They have a lot of negative qualities: from heavy metals; dissolve liquid and solid pollutants, which, if not for surfactants, would settle on the filters; serve as a breeding ground for dangerous microorganisms. An increased level of surfactant content was noted in the rivers: Volga, Oka, Kama, Irtysh, Don, Northern Dvina, Ob, Tom, Tobol, Neva.


Lead- one of the most important types of mineral raw materials and at the same time - a global pollutant of the environment. Native metal is rare in nature, but is found in large quantities of mineral deposits and ores.

How does lead get into water?

Lead compounds enter natural bodies of water with precipitation due to the leaching of rocks and soils. But the biggest contribution to the pollution of water sources comes from human activities. A huge amount of lead enters water with wastewater from industrial and mining enterprises. The use of tetraethylene lead in automobile fuel, household waste, and coal combustion are also some of the most common ways that heavy metals enter ground and open waters.


There are frequent cases of the presence of lead in centralized water supplies. In many old-style houses, there are still lead pipes or pipeline elements, particles of which, during the process of corrosion of their surfaces, fall directly into the apartments.

Why is lead in water dangerous?

According to SanPin requirements, the concentration of lead compounds in drinking water should not exceed 0.03 mg/l. However, this substance is extremely toxic and tends to accumulate in the body, which, with regular use of even microscopic doses, can cause severe poisoning in both acute and chronic forms.

The first symptoms of lead intoxication are insomnia, lethargy, weakness in the limbs, headaches, irritability, dizziness, nausea, depression, loss of appetite and others. If you do not consult a doctor in time, the symptoms only intensify and new ones appear, such as impaired coordination of movements, speech, cramps and muscle pain. More severe forms of intoxication can lead to coma and even death.

In chronic forms, poisoning with lead compounds can provoke diseases such as encephalopathy (damage to the cerebral cortex), iron deficiency anemia and oxygen starvation of tissues, nephropathy (damage to the kidney tubules), and primary infertility. This dangerous metal tends to block the body's production of vitamin D and the absorption of calcium from food. Accumulating mainly in bone tissue, it causes brittle bones and damage to teeth, hair and nails.

Lead in water is especially dangerous for young children and pregnant women. Research confirms that it negatively affects the child’s mental abilities and the normal development of the fetus.

Purification of drinking water from toxic substances is very important for human health and life. Lead concentration can be determined by

- 1.2900 mg/l which is 4.30 times higher than normal. (Normal: 0.3000 mg/l)

Description of the chemical element

Iron (Fe)- chemical element of group VIII of the periodic table, atomic number 26. It is one of the most common metals in the earth’s crust. Iron is usually called its alloys with a low content of impurities: steel, cast iron and stainless steel.

Functions of iron

  • The main source for the synthesis of hemoglobin, which is the carrier of oxygen molecules in the blood.
  • Participates in the synthesis of collagen, which forms the basis of the connective tissues of the human body: tendons, bones and cartilage. Iron makes them strong.
  • Participates in oxidative processes in cells. Without iron, the formation of red blood cells, which regulate redox mechanisms already at the embryonic stage of brain development, is impossible. If this process fails, the child may be born defective.

Iron intake standards

  • Physiological requirement for adults per day: for men 10 mg; for women – 15 mg.
  • The physiological need for children per day is from 4 to 18 mg.
  • The maximum permissible daily dose is 45 mg.

Dangerous doses of iron

  • Toxic dose – 200 mg.
  • Lethal dose – 7-35 g.

Maximum permissible concentration (MPC) of iron in water – 0.3 mg/l

Iron hazard class – 3 (hazardous)

High concentration

In this area, there is a high iron content in the water, which significantly worsens its properties, giving an unpleasant astringent taste, and makes the water of little use. Exceeding the maximum permissible concentration of iron in water carries the following health risks:

  • allergic reactions;
  • blood and liver diseases (hemochromatosis);
  • negative impact on the reproductive function of the body (infertility);
  • atherosclerosis and heart attack;
  • toxic effects with a complex of symptoms: diarrhea, vomiting, a sharp decrease in blood pressure, inflammation of the kidneys and paralysis of the nervous system.

Exceeding the concentration of this element leads to risks: , ,


The presence of these elements in water increases health risks:


The water in this area does not exceed the content of chemical elements:

Description of the chemical element

Chromium (Cr)- chemical element of group VI of the periodic table, atomic number 24. It is a solid metal of bluish-white color. Is a microelement.

May be present in water in the form of Cr3+ and toxic chromium in the form of dichromates and chromates.

Chrome functions

  • Regulates carbohydrate metabolism: together with insulin, it participates in the metabolism of sugar.
  • Transport of proteins.
  • Promotes growth.
  • Prevents and reduces high blood pressure.
  • Prevents the development of diabetes.

Chromium consumption standards

  • For adult men and women, the required daily dose of chromium is 50 mg.
  • The required daily dose of chromium for children from 1 year to 3 years is 11 mg;
    • from 3 to 11 years – 15 mg;
    • from 11 to 14 years – 25 mg.

There are no official data on the maximum permissible daily intake of chromium.

Maximum permissible concentration (MPC) of chromium in water – 0.05 mg/l

Chromium hazard class – 3 (hazardous)

Low concentration

In this area, the chromium content does not exceed the maximum permissible concentration in water. A deficiency of chromium consumed in water and food can lead to the development of the following pathological conditions:

  • changes in blood glucose levels;
  • may contribute to the development of atherosclerosis and diabetes.

Description of the chemical element

Cadmium (Cd)- chemical element of group II of the periodic table, atomic number 48. It is a soft, malleable, malleable metal of silver-white color.

In water, cadmium is present in the form of Cd2+ ions and belongs to the class of toxic heavy metals.

In the body, cadmium is found in a special protein called metallothionein.

Functions of cadmium

  • The function of cadmium in thionein is to bind and transport heavy metals and detoxify them.
  • Activates several zinc-dependent enzymes: tryptophan oxygenase, DALK dehydratase, carboxypeptidase.

Cadmium consumption standards

The following doses of aluminum compounds are considered toxic to humans (mg/kg body weight):

  • An adult’s body receives 10-20 mcg of cadmium per day. However, it is believed that the optimal intensity of cadmium intake should be 1-5 mcg.

Maximum permissible concentration (MPC) of cadmium in water – 0.001 mg/l

Cadmium hazard class – 2 (highly dangerous)

Low concentration

In this area, the cadmium content does not exceed the maximum permissible concentration in water. Cadmium deficiency in the body can develop with insufficient intake (0.5 mcg/day or less), which can lead to growth retardation.

Health risks

  • risk of developing diseases of the nervous system
  • risk of developing kidney disease
  • risk of developing heart and vascular diseases
  • risk of developing blood diseases
  • risk of developing dental and bone diseases
  • risk of developing skin diseases and hair loss

Description of the chemical element

Lead (Pb)- chemical element of group IV of the periodic table, atomic number 82. It is a malleable, relatively low-melting gray metal.

Lead is present in water in the form of Pb2+ cations and belongs to the class of toxic heavy metals.

Lead functions

  • Affects growth.
  • Participates in metabolic processes of bone tissue.
  • Participates in iron metabolism.
  • Affects hemoglobin concentration.
  • Changes the actions of some enzymes.

Lead consumption standards

It is believed that the optimal rate of lead intake into the human body is 10-20 mcg/day.

Dangerous doses of lead

  • Toxic dose – 1 mg.
  • Lethal dose – 10 g.

Maximum permissible concentration (MPC) of lead in water – 0.03 mg/l

Lead hazard class – 2 (highly dangerous)

Low concentration

In this area, the lead content does not exceed the maximum permissible concentration in water. Lead deficiency in the body can develop with insufficient intake of this element (1 mcg/day or less). There is currently no data on the symptoms of lead deficiency in the human body.

Description of the chemical element

Fluorine (F)- chemical element of group VII of the periodic table, atomic number 9. It is a chemically active non-metal and the strongest oxidizing agent, and is the lightest element from the halogen group. Very poisonous.

In the body, fluorine is in a bound state, usually in the form of sparingly soluble salts with calcium, magnesium, and iron. Fluorine is the main component of mineral metabolism; fluorine compounds are found in all tissues of the human body. The highest fluoride content is in bones and teeth.

Functions of fluorine

  • Depends on fluorine:
    • condition of bone tissue, its strength and hardness;
    • proper formation of skeletal bones;
    • condition and growth of hair, nails and teeth.
  • Fluoride, together with calcium and phosphorus, prevents the development of caries - it penetrates microcracks in tooth enamel and smoothes them out.
  • Participates in the process of hematopoiesis.
  • Supports immunity.
  • Provides prevention of osteoporosis, and in case of fractures accelerates bone healing.
  • Thanks to fluoride, the body better absorbs iron and gets rid of heavy metal salts and radionuclides.

Fluoride consumption standards

  • For adult men and women, the daily dose of fluoride is 4 mg.
  • Daily dose of fluoride for children:
    • from 0 to 6 months – 1 mg;
    • from 6 months to 1 year – 1.2 mg;
    • from 1 year to 3 years – 1.4 mg;
    • from 3 to 7 years – 3 mg;
    • from 7 to 11 years – 3 mg;
    • from 11 to 14 years – 4 mg.
  • The maximum permissible daily dose is 10 mg

Dangerous doses of fluoride

  • Toxic dose – 20 mg.
  • Lethal dose – 2 g.

Maximum permissible concentration (MAC) of fluorine in water:

  • Fluorine for climatic region I-II – 1.5 mg/l;
  • Fluorine for climatic region III – 1.2 mg/l;
  • Fluorine for climatic region IV is 0.7 mg/l.

Fluorine hazard class – 2 (highly dangerous)

Low concentration

In this area, the fluorine content does not exceed the maximum permissible concentration. It should be remembered that a deficiency of fluoride consumed in water and food can lead to the following diseases and conditions:

  • the appearance of dental caries (when the fluorine content in water is less than 0.5 mg/l, the phenomenon of fluoride deficiency develops and caries occurs);
  • bone damage (osteoporosis);
  • underdevelopment of the body, in particular the skeleton and teeth.

Description of the chemical element

Boron (B)- chemical element of group III of the periodic system, atomic number 5. It is a colorless, gray or red crystalline or dark amorphous substance.

Boron functions

  • Participates in the metabolism of calcium, magnesium, phosphorus.
  • Promotes growth and regeneration of bone tissue.
  • It has antiseptic and antitumor properties.

Boron consumption standards

The daily intake of boron is 2 mg.

The upper acceptable intake level is 13 mg.

Dangerous doses

  • Toxic dose – from 4 g.

Maximum permissible concentration (MAC) of boron in water – 0.5 mg/l

Boron hazard class – 2 (highly dangerous)

Low concentration

In this area, the boron content does not exceed the maximum permissible concentration in water. Water does not pose any health risks. However, a lack of boron consumed through water and food can lead to:

  • to deterioration of mineral metabolism of bone tissue;
  • growth retardation;
  • osteoporosis;
  • urolithiasis;
  • decreased intelligence;
  • retinal dystrophy.

Russia, Ural Federal District, Chelyabinsk region, Kopeysk

These samples exceeded the maximum permissible concentration:


This leads to the following health risks.

Are we always aware of what water means to us - this colorless, odorless and tasteless liquid? Scientists have long discovered a direct connection between the quality of drinking water and human life expectancy. Have you ever thought about what kind of water you drink every day? Most of us, despite the warnings of doctors, prefer tap water - which has gone through several levels of purification and flows through pipes to the tap.
According to the laboratory of drinking water supply of the Research Institute of Human Ecology and Environment of the Russian Academy of Medical Sciences, 90% of water supply networks supply water to homes that does not meet sanitary standards. The main reason for the presence of nitrates, pesticides, petroleum products and heavy metal salts in tap water that are harmful to health is the catastrophic state of the water supply systems.
According to the State Sanitary and Epidemiological Supervision Service, the quality of drinking water is very low in Buryatia, the Primorsky Territory, and the Arkhangelsk, Kaliningrad, Tomsk, Kemerovo, Kurgan, and Yaroslavl regions.
With centralized water supply, it is legally determined that the water supplied to the consumer must be safe for health; it is understood that the content of harmful substances in water should not exceed maximum permissible concentrations. Lead compounds remain one of the most important factors in contamination of tap water. The main source is water pipes and lead solder when joining pipes. Although many countries have long banned the industrial production of pipes containing lead. In fact, manufacturers still use lead solder today. As a result of the consumption of these materials, lead appears in drinking water.
Lead has neither taste nor smell; you can determine whether it is in drinking water by conducting a chemical analysis. Although, visually, you can do without it: by looking at your water pipes, you yourself, without difficulty, can determine whether you should fear for your health. If the pipes are gray in appearance and can be easily scratched with a sharp object, this is lead, and the natural corrosion that occurs in the water supply will certainly lead to it getting into the drinking water. Water with high lead content can cause acute or chronic poisoning in humans.
In this regard, research into the quality of tap water, which can have not only positive but also negative effects on human health, is relevant. We find the topic interesting because the water we drink has a great impact on our health. And we wanted to be sure that home water would not harm the health of our families and friends.
There is a significant amount of literature devoted to this topic. The most detailed material on the requirements for the quality of drinking tap water and the effect of its composition on human health is presented in the book by Itskova A.I. “Our life through the eyes of a doctor.” A serious study devoted to the problem of drinking water quality is reflected in the materials of Mikhail Akhmanov’s book “The Water We Drink.” The author pays special attention to methods of water purification at home, evaluates the effectiveness and usefulness of filters offered by domestic and foreign companies. While working on the book, the researcher collected information about the quality of drinking water in different regions of Russia and received advice from leading experts. We consider this material particularly interesting and informative, and we recommend it for reading to everyone who cares about their own health.

Novelty: Identification of the characteristics of lead content in tap drinking water on human health

Target: Study of the influence of lead in tap water on human health.

Tasks:
find sources of information and analyze data on the impact of lead in tap water on human health;
Having studied literary sources, select a method for detecting lead in tap water, and conduct research;
conduct a survey of classmates and friends about their knowledge of the composition of drinking water and its impact on our health;
develop recommendations for improving water at home in accessible ways, inform friends and classmates.

Object of study: tap water from the water utility of the central district of the city of Kiselevsk.

Subject of study: lead content in tap water.

Hypothesis: Let’s assume that studying the impact of lead in tap water on health will be effective if we study modern literary and Internet sources devoted to this problem, select an accessible method for research for identifying lead in tap water, develop recommendations for improving water at home, and inform classmates.

Research methods: analysis of literary and information sources, sociological survey, observation, analysis, experiment (research of the composition of drinking water using selected methods), interviews, self-analysis.

Practical significance: The results of our activities will provide information on the state of the quality of tap water regarding the content of lead impurities. The materials and results of the work can be used in extracurricular classes on ecology, as well as to inform students and their parents.

Location of the study: Central district of Kiselevsk

Literature review
During the research work, a literature review was conducted on the research topic, the influence of drinking water quality on health, and drinking water quality standards were studied.
We found that lead compounds in tap water remain one of the most important factors harmful to human health. One of the main sources is old water pipes. Lead is a heavy metal that can accumulate in the human body and lead to severe poisoning, the maximum permissible value of which in water should not exceed 0.01 - 0.03 mg/l. In nature, lead occurs in the form of various compounds, the most important of which is the lead luster PbS. The abundance of lead in the earth's crust is 0.0016 wt. %.
Lead is a bluish-white heavy metal with a density of 11.344 g/cm3. It is very soft and can be easily cut with a knife. The melting point of lead is 327.3 °C. In air, lead quickly becomes covered with a thin layer of oxide, protecting it from further oxidation.
The Department of Environmental Protection has set the maximum permissible level of lead in drinking water at 15 parts per billion.
It is especially dangerous for children. According to statistics, about 4 million children in the world suffer from the consequences of lead poisoning. Its toxic effect is associated with the suppression of hemoglobin reproduction and the deactivation of enzymes in the brain and nervous system. Depending on the concentration of lead in the body, this leads to pathology of varying severity.
Sources of lead (Pb) in tap water:
- old water pipes;
- lead contained in water pipe adapters
- lead soldered seams for pipes;
- “soft” solders (the most famous is “tertiary” - an alloy of lead and tin) - a method of connecting pipes to each other;
- lead dissolved in natural water; lead pollutants that enter natural waters in various ways (for example, gasoline);
Constantly ingesting small doses of lead into the body is dangerous, since this metal tends to accumulate in organs and tissues, causing chronic poisoning. There are practically no organs in which lead does not accumulate, but most of all it settles in nails, hair and gums. Traces of poisoning begin to appear when the amount of lead exceeds 40-60 mg/100 ml. This affects the peripheral nervous system, liver and kidneys.
Lead has a detrimental effect on red blood cells, so long-term consumption of water, even with small doses of lead, can lead to anemia over time, as red blood cells lose their ability to carry oxygen.
In addition, lead blocks the body's intake of vitamin D, which promotes the accumulation of calcium in the bones. Drinking water containing lead is especially dangerous for young children and pregnant women. The latter may be at risk of premature birth or fetal deformities.
To detect lead, we were looking for a technique based on a color reaction - qualitative analysis. The main selection criterion was that the technique was easy to implement and could be performed in a school laboratory.

Research methodology
Most modern homes have non-metallic pipes installed, but there are still many homes that have old pipes that are causing higher levels of lead in the water. Activities carried out in recent years by various structures have made it possible to significantly reduce the lead content in water. But metal taps and pipes connecting houses to the main water pipe and household taps sometimes still exacerbate this problem. Water that lingers in pipes and taps for several hours absorbs lead particles that are formed as a result of corrosion of the pipe itself or the seams on it.
There is no more accurate way to determine the level of lead in your drinking water than to test its chemistry.
Based on literature data, the most convenient and optimal method for determining lead in tap water was selected.
We used the laboratory work methodology, which is available for conducting experiments in the school laboratory (the methodology was borrowed from foreign experience in teaching chemistry).
The proposed method for detecting lead is based on a color reaction, which results in the formation of a precipitate of lead iodide.
If sediment does not form and the water does not change color, it means that the tap water does not contain lead in appreciable quantities. The sensitivity of the method is 0.1 mg in 5 ml of solution.
Evaluation of results: water sediment is characterized: quantitatively - by layer thickness; in relation to the volume of the water sample - insignificant, insignificant, noticeable, large; qualitatively - in composition: amorphous, crystalline, flocculent, silty, sandy.
Reagents and equipment:
- clean test tubes;
- potassium iodide solution;
- acetic acid;
- alcohol lamp or gas burner;
- ice or container with cold water;
- sulfuric acid;
- measuring cylinder with a capacity of 10 ml;
- milliliter glasses (glassware is washed with distilled water).

Operating procedure:
Purpose: Determination of lead content in samples of tap water from three sources of residential premises in the central area of ​​the city, taking into account the installed water pipes. We examined water samples from three water supply sources: water was collected from Municipal Budgetary Educational Institution Secondary School No. 14, Municipal Budgetary Educational Institution DO TsDT; residential building on st. Unzhakova, 16. It is necessary to establish whether the water contains soluble lead compounds.
There is a very characteristic and highly sensitive reaction, which can rightfully be called one of the most beautiful in chemistry. It is based on the ability of lead to interact with iodine, forming the poorly soluble compound PbI2.
Experimental part:
Progress:
1) pour water samples into numbered test tubes;
2) preparation of the reagent solution;
3) conducting the experiment.

Experience No. 1. Determination of lead compounds in water using a solution of potassium iodide - KI.
1. Transfer 10 ml of water sample from bottle No. 1 into a clean test tube made of refractory glass;
2. Added 1 ml of reagent solution (potassium iodide solution - KI, acidified with a few drops of acetic acid, for better reaction).3
3. Study of changes in water sample. Shake the contents of the test tube. If the water contained soluble lead compounds, a yellow precipitate of lead iodide will form. He is unremarkable in appearance. But if you heat the test tube well on the flame of an alcohol lamp or gas burner (the precipitate should dissolve), and then quickly cool it, for example, by placing it in ice or a container with cold water, then the PbI2 precipitate will fall out again, only now in the form of beautiful golden crystals.

The water in test tube No. 1 slightly changed color, the color is light-light yellow, there is noticeable slight turbidity, which indicates insignificant lead impurities in the water, corresponding to the maximum permissible concentration;

The water in test tube No. 3 has not changed its qualities, no turbidity, color change or sediment was detected;

Experience No. 2. Determination of lead compounds using sulfuric acid.
Add 10 ml of the water to be tested into a test tube and add 2-3 drops of sulfuric acid.
1. When interacting with the lead ion Pb^2+, a reaction of the type occurs: K2SO4 + Pb(NO3)2 = PbSO4 + 2KNO3.
2. The resulting lead sulfate precipitates in the form of a dense white precipitate.
3. Control reaction.
It is worth noting that the formation of a precipitate that looks the same is a characteristic reaction to barium ion. How can you be sure that it is not barium sulfate? To do this, you need to carry out a control reaction: add a strong alkali solution to the precipitate, and then heat the test tube. If it is lead sulfate, then the precipitate will gradually disappear due to the formation of a soluble complex salt. The reaction proceeds according to the following scheme: PbSO4 + 4NaOH = Na2 + Na2SO4. Barium sulfate will remain as a precipitate during the same control test.
The experiment was carried out with each of the taken tap water samples, upon completion the following conclusions were made:
In the water from test tube No. 1, slight turbidity was observed, no sediment was detected;
The water in test tube No. 2 has not changed its qualities, no turbidity, color change or sediment was detected;
The water in test tube No. 3 did not change its qualities; no turbidity, color change or sediment was detected.
Evaluation of the results: based on the nature of the sediment that fell and the color of the water, we determined the approximate content of lead ions: in the absence of sediment, the concentration of lead ions is less than 0.01 mg/l; with weakly expressed sediment, or a change in the color of the water that appears after a few minutes - up to 0.3 mg/l; a pronounced sediment indicates a fairly high content of lead ions (more than 0.3 mg/l).
The maximum permissible concentration of lead in tap water should not exceed 0.01-0.03 mg/l.
Conclusion: Experience shows that during observations of three tested water samples, the assumption that tap water may contain lead impurities was confirmed; it is positive that the detected impurities do not exceed the maximum permissible standards. You should pay attention to the quality and material of the water pipes where the water intake for test tube No. 1 was taken.

Results of interviews with specialists from JSC PA Vodokanal
To obtain detailed information about the existence of this problem in our city, we prepared for a conversation with specialists from the service that provides us with water. A list of questions was developed and interviews were conducted with the main specialists of the Kiselevsky Vodokanal:
Pavel Aleksandrovich Saprykin - Deputy Director for Production of the Kiselevsky branch of OJSC PA Vodokanal and Viktor Viktorovich Gaivoronsky - Head of Emergency Repair Work of OJSC PA Vodokanal.
Conclusion: From the answers of the experts, it became clear that this problem does not arise from the urban part of the pipes, which means that lead is released in the pipes located in your home. The main source of lead in tap water is the destruction of lead-containing elements of water supply networks (solders, brass alloys).

Methodology and results of the survey
When carrying out research work, we conducted a survey among students in my class, followed by statistical processing and analysis of the data obtained. 22 people took part in the survey.
The procedure for conducting the survey:
1.Development of questionnaires;
2. Conducting testing, each of the respondents filled out the questionnaire independently to avoid outside influence;
3. Processing and analysis of the results obtained.
Survey results:
In order to determine awareness of the safety of tap water and methods of its purification, we developed survey questions and conducted a survey of friends and classmates, as a result we identified:
1.73% of surveyed classmates drink raw tap water;
2.Only 59% of students know what water pipes are installed in apartments;
3.59% of respondents have suspicions about the quality and safety of the tap water they drink;
4. They do not know about the impurities of heavy metals that are harmful to health, which may be contained in tap water - 73% of respondents;
5. 95% of respondents know about methods of purifying tap water
6.The most popular methods of water purification in the families of classmates are filtering and boiling, 95% prefer boiling. The water settling method is not used.
Conclusion: More than 70% of respondents do not know what harmful impurities may be contained in tap water and effective methods of purifying water at home.