Environmental pollution.Pollution in the narrow sense is understood as the introduction into some environment of new physical, chemical, and biological agents not characteristic of it, or the exceeding of the natural level of these agents in the environment.

3.1. Chemical pollution of the environment

Substances that adversely affect organisms and lead to disease are usually grouped into several categories. The most important of these are:

a) carcinogens - (Lat. cancer ~ crab/cancer, genesis—origin) cause malignant tumors. About 500 such substances are currently known. Among the strongest of them are benzo(a)pyrene and other polycyclic aromatic hydrocarbons, as well as ultraviolet rays, X-rays, radioactive isotopes, epoxy resins, nitrites, nitrosamines, asbestos, etc.;

b) mutagens ~ (Lat. mutatio - change, alteration) cause changes in the number and structure of chromosomes. These include: X-ray irradiation, gamma rays, neutrons, benzo(a)pyrene, colchicine, certain viruses, etc.;

c) teratogens (Greek teras, teratos — monster, deformity) - substances that cause defects in individual development and deformities. Virtually any factor whose effect exceeds the optimal level can be a teratogen. Mutagens often act as teratogens, as do pollutants such as pesticides, fertilizers, noise, etc.

Sometimes embryogens (Greek embryon — embryo) are also distinguished - substances that cause disturbances in embryonic development. Teratogens, mutagens, and other substances (for example, alcohol, drugs, etc.) often act as embryogens.

1. Hazardous inorganic substances

Aluminum - Death of nerve cells, paralysis of the heart muscle.

Arsenic - Cancers, skin cancer

Cadmium – paralysis, diseases of the CNS, liver cirrhosis. Exposure to cadmium disrupts kidney function and causes irreversible changes in the skeleton. Its earliest symptoms are damage to the kidneys, nervous system, and reproductive organs. Later, acute bone pain occurs in the back and legs. Impaired lung function is also typical.

Copper – brain function disorders, schizophrenia, malignant neoplasms,

Chromium (hexavalent) - disruption of carbohydrate metabolism, malignant neoplasms,

Fluorine – tooth caries or fluorosis,

Lead – diseases of the CNS, encephalopathy, leukemia.

Human poisoning by mercury is known as Minamata disease.

2. Organic substances hazardous to health

1. The harmful effect of nitrates on the human body

1. Under the action of the enzyme nitrate reductase, nitrates are reduced to nitrites, which react with hemoglobin in the blood and oxidize its divalent iron to trivalent iron. This produces a substance called methemoglobin, which is no longer able to carry oxygen. As a result, normal respiration of the body's cells and tissues is disrupted (tissue hypoxia), causing lactic acid and cholesterol to accumulate and protein levels to drop sharply.

2. Nitrates are especially dangerous for infants, since their enzymatic system is immature and the reduction of methemoglobin back to hemoglobin proceeds slowly.

3. Nitrates promote the development of pathogenic (harmful) intestinal microflora, which releases toxic substances — toxins — into the human body, resulting in toxication, i.e., poisoning of the organism. The main signs of nitrate poisoning in humans are:

a) blueness of the nails, face, lips, and visible mucous membranes;

b) nausea, vomiting, abdominal pain;

c) diarrhea, often with blood, enlargement of the liver, yellowing of the whites of the eyes;

d) headaches, increased fatigue, drowsiness, decreased working capacity;

e) shortness of breath, increased heart rate, up to loss of consciousness;

f) in severe poisoning — death.

1. Nitrates reduce the content of vitamins in food, which are part of many enzymes, stimulate the action of hormones, and through them affect all types of metabolism.

2. In pregnant women, miscarriages occur, and in men — a decrease in potency.

3. With prolonged intake of nitrates into the human body (even in small doses), the amount of iodine decreases, which leads to enlargement of the thyroid gland.

4. It has been established that nitrates significantly contribute to the occurrence of cancerous tumors in the gastrointestinal tract.

5. Nitrates can cause sharp vasodilation, resulting in a drop in blood pressure.

Scientists believe that in the human body nitrates are converted into other nitrogen compounds, primarily nitroamines.

Nitroamines promote the formation of malignant tumors and may be the cause of 70 — 90% of cancer cases, the occurrence of which is attributed to environmental factors.

Routes by which nitrates enter the human body

Nitrates enter the human body in various ways:

1) through food:

a) of plant origin,

b) of animal origin;

1. through drinking water;

2. through medications.

Some nitrates can form within the human body itself during metabolism. Nitrates also enter the human body with water, which is one of the basic conditions for normal human life. Contaminated drinking water causes 70 — 80% of all existing diseases, which shorten human life expectancy by 30%. According to WHO data, more than 2 billion people on Earth fall ill for this reason, of whom 3.5 million die (90% of them being children under 5 years old). Drinking water from underground sources contains up to 200 mg/l of nitrates, much less in water from artesian wells.

Nitrates also enter the human body through tobacco. It has been found that some tobacco varieties contain up to 500 mg of nitrates per 100 g of dry matter.

Ways to reduce the influence of nitrates in plants on the human body

1. The amount of nitrates decreases with heat treatment of vegetables

1. Since there are more nitrates in the peel of vegetables and fruits, they (especially cucumbers and zucchini) should be peeled, and for aromatic herbs, the stems should be discarded and only the leaves used.

2. Vegetables and fruits should be stored in the refrigerator, since at a temperature of 2 "C the conversion of nitrates into more toxic substances — nitrites — is impossible.

3. To reduce the content of nitrites in the human body, one should consume sufficient amounts of vitamin C (ascorbic acid) and vitamin E, since they reduce the harmful effects of nitrates and nitrites.

Organic substances hazardous to health

Among organic compounds, halogenated hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) are the most dangerous.

Halogenated hydrocarbons. This group includes organic compounds in which one or more carbon atoms are replaced by chlorine, bromine, iodine, or fluorine. Chlorinated hydrocarbons are the most common. Many of them are quite stable, are readily absorbed by organisms, and accumulate intensively in individual organs and tissues. These include polyvinyl chloride, or PVC; polychlorinated biphenyls, or PCBs, DDT (a pesticide), tetrachlorophenol, and tetrachloroethylene (solvents). This group also includes highly toxic substances — dioxins. Let us briefly consider some of the hydrocarbons named.

The most common polymer — polyethylene (about 40% of plastics production) is used for packaging goods, in the production of dishware, canning lids, and in the manufacture of toys, furniture, and building materials. It does not decompose for a long time.

It is not recommended to pour hot water into polyethylene items, since at elevated temperatures low-molecular-weight compounds migrate more actively and their quantity may exceed the permissible level, i.e., make the water unsafe for human health. It is also inadvisable to store bread and bakery products, especially dark bread, in polyethylene.

Another synthetic polymer — polyamide is used for the production of textile fibers and as a component of rigid plastics.

Polystyrene (15% of plastics production) is used to make dishware, toys, facing tiles, soap dishes, rulers, etc.

Teflon — one of the trade names for polytetrafluoroethylene. Frying pans with Teflon coating must not be overheated (toxic fumes are produced). Pans with a scratched coating should not be used, since Teflon particles can get into food from such dishware, and moreover, areas where the Teflon coating is damaged overheat especially easily.

Second in importance after polyethylene is polyvinylchloride (PVC).

PVC products pose a great health hazard: flooring, windows, doors, blinds, cables, pipes, tablecloths, packaging material, dishware, toys, insulating materials, various stationery and school supplies, some car parts, medical instruments, etc. About 40% of plastic products are made of PVC. Vinyl chloride is an occupational carcinogen; it is officially recognized as a first-hazard-group substance whose effects can lead to cancerous tumors in humans (in particular, tumors of the brain, liver, and lungs). Vinyl chloride is also a neurotropic poison that has a harmful effect on the nervous system.

When PVC burns, particularly in a fire, carbon monoxide is released first, then hydrochloric acid vapors, and finally dioxins. Toxic dust settles on walls and ceilings and remains in the air for a long time. Burning 1 kg of PVC produces about 50 µg of dioxins. This amount is enough to cause cancerous tumors in 50 thousand laboratory animals. That is why many countries (the USA, France, Switzerland, Belgium) have already abandoned the use of PVC packaging in the food industry and trade, and prohibit the use of PVC materials in residential construction.

Plasticizers — substances from the phthalate group, usually diethyl phthalate or dibutyl phthalate. They «float» in PVC without forming strong chemical bonds, so they are easily released, in particular when a child licks a toy made of this material. The maximum permissible level of phthalates in the human body is about 45 µg per 1 kg of body weight. A child gnawing on a PVC teething ring, however, consumes 2219 µg of phthalates per 1 kg of body weight in 3 hours, i.e., 50 times the norm.

Phthalates negatively affect the nervous system — the child becomes nervous, irritable, sometimes even aggressive. By acting on the respiratory tract, substances from the phthalate group cause spasms and can contribute to the occurrence of chronic tonsillitis (inflammation of the tonsils) and asthma. Doctors have found that phthalates entering children's bodies lead to chronic diseases that manifest in adulthood. Phthalates provoke serious damage to the liver and kidneys, the immune and reproductive systems: a decrease in sperm count, infertility and miscarriages, cancer, and even genetic changes.

Polychlorinated biphenyls (PCBs). Only in the 1960s were the strongly pronounced toxic properties of PCBs and their ability to accumulate in various organs (kidneys, spleen, liver) and in mother's milk discovered. This pollutant often leads to death. - The latter manifested itself as a severe skin disease known as chloracne. This disease is accompanied by prolonged suppurative processes, damage to the liver, kidneys, pancreas, and nervous system. The possibility of mutagenic processes, as well as changes in skin pigmentation in newborns (dark skin), cannot be excluded.

Dioxins. Substances of this group are a product of the transformation of halogenated hydrocarbons. This most powerful of known poisons has recently attracted increasing attention. To date, the carcinogenic, mutagenic, and teratogenic effects of dioxin have been established. In addition, dioxin seriously affects the ability to reproduce. The poison enters the human body in various ways: through the skin, through breathing, with food. It is among the most toxic and dangerous organic substances. Its half-life is 10 to 20 years (somewhat less in the human body). Dioxin accumulates mainly in fatty tissues and most intensively affects the skin, liver, and certain tissues. In addition, it causes a disease known as «chloracne».

Phenol and its derivatives. These substances also belong to the group of widely distributed, highly toxic compounds. Inhaling phenol vapors usually irritates the mucous membranes, and contact with skin causes burns. Phenol poisoning often results in damage to the liver and kidneys and changes in blood composition. It has a negative effect on heredity. There is evidence of its carcinogenic and teratogenic properties.

3. 2. PHYSICAL FACTORS OF THE ENVIRONMENT

1. RADIATION POLLUTION OF THE ENVIRONMENT

One of the powerful factors undermining human health is elevated radioactive radiation.

Humans are accustomed to living under conditions of natural background radioactive irradiation. However, elevated irradiation leads to reduced immunity, cancer, and radiation sickness. Consuming food contaminated with radioactive substances has an even stronger effect on health.

Let us give some data on the level of radioactive irradiation under modern conditions:

watching (1.5 h) one hockey match on television — 1 µrem;

background radiation per year (F = 15 µR/h) — 130 mrem;

background radiation over 70 years of life — 9.2 rem;

permissible population exposure per year — 500 mrem;

fluorography — 0.05 rem;

lower threshold for development of mild radiation sickness — 100 rem;

severe radiation sickness (50% of exposed die) — 450 rem.

The annual dose of radioactive exposure of the population exceeds its background exposure dose by a factor of 5.

Radon

The inert radioactive gas radon is formed by the decay of uranium-238, thorium-232, and radium-226 contained in soils and many minerals. The ground on which houses stand and the building materials from which they are made can act as powerful sources of radon. Seeping through the foundation and floor from the soil, or being released from materials used in construction, it accumulates in premises, especially on lower floors, often resulting in rather high radiation levels. In Sweden and Finland, buildings were discovered in which the radon concentration was 5000 times higher than its content in outdoor air. Not only radon itself is dangerous, but also its decay products — natural radioactive aerosols. When breathed in, they enter the lungs and attach to tissues; internal irradiation of the person by alpha particles occurs. The medical consequences of this are expressed in an increase in the number of oncological diseases. According to the UN Scientific Committee on the Effects of Atomic Radiation, about 20% of all lung cancer cases may be due to exposure to radon and its decay products.

2. Electromagnetic pollution of the environment

Over the past few decades, a new environmental factor has formed — electromagnetic fields (EMF) of anthropogenic origin — electrosmog.

The field intensity has grown especially sharply near power transmission lines, radio and television stations, radar and radio communication equipment (including mobile and satellite), various power and energy-intensive installations, and urban electric transport. In recent years, the number of various EMF sources in cities across the entire frequency range (up to tens of GHz) has increased sharply. These include radiotelephones (cellular communication systems), traffic police radars, microwave ovens, computers, and so on.

Effects

Among the recorded consequences of electromagnetic pollution's effect on humans are damage to basic body functions, including impairment of the cardiovascular and digestive systems, the development of mental disorders, and others.

Prolonged exposure to EMF, even at a relatively weak level, can result in cancer, behavioral changes, a tendency to develop stress reactions, insomnia, memory loss, Parkinson's and Alzheimer's disease, bronchitis, asthma, suppression of sexual function, arrhythmia, migraine, chronic fatigue, and many other conditions, including an increase in the suicide rate in large cities. It has been proven that EMF exposure negatively affects cerebral blood circulation.

According to some data, a significant portion of myocardial infarction cases in large cities is caused by surges of powerful low-frequency man-made electromagnetic fields.

Hygienic standards allow a worker to stay in the exposure zone of an electric field with a frequency of 50 Hz and E = 10 kV/m for no more than 3 hours, and for E = 20 kV/m and above, no more than 10 minutes a day. Living close to power lines is dangerous.

Scientists have established that constant presence of people in conditions of a low-frequency magnetic field with an induction of 0.3 — 6 µT leads to asthenia, decreased libido, melancholy, and the appearance of depression and irritability.

The sources of dangerous magnetic fields in our homes are all high-current appliances: grills, irons, range hoods, refrigerators, televisions, computers and power supplies, and the common power cable of the entrance or elevator.

1. First place among dangerous appliances belongs to appliances for cooking food — the electric stove and microwave oven. High magnetic field values are also recorded for dishwashers and washing machines with a drying function.

Risk zone of household appliances

2. In electric trains (commuter trains, metro, trams, trolleybuses), the EMF level exceeds the natural background hundreds of thousands of times, and the magnetic field strength can reach 10 mT and exceed the safe level by 5000 times. Exposure to such fields can serve as a trigger mechanism for pathological processes in people suffering from cardiovascular diseases and can lead to a heart attack.

Electromagnetic radiation of ultra-high frequencies poses a certain danger, contributing to increased fatigue or, depending on individual characteristics of the organism, excessive excitability, as well as, when the eyes are exposed to ultra-high-frequency (microwave) radiation, the development of cataracts.

3. The next source of powerful electromagnetic radiation is pocket cellular radiotelephones. Household cordless phones do not pose a danger. For handheld radiotelephones, the radiation power ranges from tenths of a watt to 10 W. Exposure of the brain to such EMF leads to brain cancer (this was encountered in the USA in the early 1990s), hormonal diseases, increased blood pressure, cardiovascular effects, and behavioral changes.

An experiment was conducted over the course of a month, in which 20 volunteers used a standard cell phone 6 days a week for 2 hours a day. As a result, they showed a steady decrease in the hormone responsible for thyroid function. At the same time, oxygen consumption decreased and the rate of metabolic processes slowed. External signs of this — hair loss, dry puffy skin with a yellowish tint, hoarse voice.

4. Computers create electromagnetic radiation across a wide spectrum: X-ray, ultraviolet, high-frequency (10 — 300 MHz), low-frequency (5 Hz—300 kHz), and an electrostatic field.

The main danger for users is the electromagnetic radiation from the monitor in the frequency range of 20 Hz—300 MHz and the static electric charge on the screen. According to aggregated data, among those working at a monitor 2 to 6 hours a day, functional disorders of the central nervous system occur on average 4.6 times more often than in control groups; cardiovascular diseases — 2 times more often; upper respiratory tract diseases — 1.9 times more often; musculoskeletal system diseases — 3.1 times more often.

The nervous, immune, and reproductive systems are most vulnerable to electromagnetic fields. Moreover, the harmful effect, like radiation, accumulates over the years. At the very least, experiments on animals have shown that prolonged contact with an intense source of electromagnetic radiation causes serious diseases of the central nervous system, leukemia, brain tumors, and hormonal disorders.

Even low-intensity electromagnetic waves disrupt «communication» between brain cells — neurons. It has long been noted, for example, that people living near high-voltage power lines and repeater towers often complain of irritability and impatience. Some develop a feeling of internal tension and fussiness. Attention and memory are impaired. Complaints of insomnia and rapid fatigue arise, immunity decreases, and infectious diseases proceed more severely. Adrenaline levels in the blood increase, blood clots more intensively — and this is a direct path to strokes and heart attacks.

Recent studies have shown that electromagnetic fields provoke autoimmune diseases (these include psoriasis, vitiligo, multiple sclerosis, and many other ailments, more than twenty of which are known in total), in which antibodies mistake the body's «own» cells for «foreign» ones and begin to destroy them.

Electromagnetic radiation negatively affects sexual function. There is evidence that intense fields can cause premature birth, developmental disorders, and even congenital deformities if the expectant mother was exposed to them in early pregnancy. Men may experience potency problems.

In addition, cell phone users are in a risk group. There is evidence of possible tumor damage to the brain, with the side of the lesion correlating with the location where the cell phone is held. People who talk on a cell phone inside a car are at particular risk, since the metal body of the car acts as a resonator and repeatedly amplifies the absorbed radiation dose.

3. Noise pollution

Significant and prolonged noise leads to decreased labor productivity, premature disruption and destruction of the hearing apparatus, cardiovascular diseases (hypertension, arrhythmia), damage to the nervous system, peptic ulcer disease, and other disorders. The most common symptoms of noise exposure are irritability, fatigue, absent-mindedness, and, as a consequence, neurosis. Noise exacerbates chronic diseases. Curiously, noise has an even more negative effect during sleep than during waking hours.

The intensity of acoustic sound vibrations is measured on a logarithmic scale in decibels (dBA) and reflects the amount of pressure that sound waves exert on the human eardrum. Noise of 0 dBA is created by a winter forest in calm weather. Rest and sleep are considered adequate when noise does not exceed 25 — 30 dBA. In institutions and enterprises, noise reaches 40 — 60 dBA. At noisy enterprises, some categories of people work at noise levels of up to 70 dBA. Noise of 80 dBA is permissible for short periods. Louder noise is harmful. The pain threshold usually lies within 120 — 130 dBA, beyond which direct damage to the hearing apparatus is possible.

In accordance with sanitary standards, the noise level near buildings during daytime should not exceed 55 dBA, and at night (from 23:00 to 7:00) — 45, in apartments — 40 and 30 dBA respectively.

The pitch of a sound is determined by the frequency of sound vibrations and is measured in hertz (Hz), i.e., the number of periods (oscillations) per second. Within the range of sounds audible to humans (from 16 to 20 thousand Hz), the most unfavorable effect on a person is exerted by noise in whose spectrum high frequencies predominate (above 800 Hz); ultrasound (vibrations with frequencies above 20 kHz) and infrasound (vibrations with frequencies from 1 to 16 Hz) are not perceived by the human ear, but they too can have an unfavorable effect. According to Austrian researchers, «noise pollution», now characteristic of large cities, shortens the life expectancy of their residents by 10—12 years.

Body's response to acoustic exposure of varying intensity

It has been established that the noise intensity (in dBA) of vehicles is as follows:

passenger car — 65 — 80;

bus — 80 — 85;

truck — 80 — 90;

ordinary train — 95—100;

aircraft at takeoff — 110—130;

large jet aircraft — 155—160.

Healthy eardrums can withstand personal music player noise of 110 dB without harm for a maximum of 1.5 minutes. French experts note that hearing impairments in the age of personal music players are actively spreading among young people, and after using such players, these people will be forced to switch to hearing aids. Even a low volume level interferes with concentration during mental work. Music, even quite quiet, reduces a student's attention while doing homework. When sound intensifies, the body produces large amounts of stress hormones, such as adrenaline. This narrows blood vessels and slows intestinal function. In the long run, all this can lead to disruptions in heart function and blood circulation. These overloads are the cause of every 5th to 10th heart attack.

The first symptom of hearing deterioration is called the «cocktail party effect». At a crowded evening gathering, a person stops distinguishing individual voices and cannot understand why everyone is laughing. The person begins to avoid crowded gatherings, which leads to social isolation. Many people with impaired hearing fall into depression and sometimes even suffer from persecution mania.

As studies have shown, inaudible sounds can also have a harmful effect on human health.

Thus, infrasound has a special effect on the human psyche: all types of intellectual activity are impaired, mood worsens, and feelings of horror, confusion, anxiety, fright, and fear appear. Scientists believe that it is precisely infrasound, silently penetrating through the thickest walls, that causes many nervous disorders among residents of large cities. It has long been noted that animals begin to become agitated long before the first signs of an earthquake or volcanic eruption. Scientists believe that this behavior is based on infrasound emitted by underground forces, which causes panic in animals.

Ultrasound, which occupies a notable place in the range of industrial noises, is also dangerous. The mechanism of its action on living organisms is extremely diverse. Cells of the nervous system are especially strongly affected by its negative effects.

Noise has a cumulative effect, meaning that acoustic irritation, accumulating in the body, increasingly suppresses the nervous system. Despite the fact that over time a habituation to noise develops (in people connected with «noisy production», as well as in residents whose windows face busy streets, or whose homes are located near railway stations or airports), physiological-biochemical adaptation of the human body to noise is impossible. This means that noise carries out its destructive effect regardless of the fact that a person has become accustomed to it and seemingly does not notice it.

Noise has become a scourge of the modern world and, in the opinion of a number of scientists, the most undesirable product of technical civilization. In terms of its effect on the body, it is sometimes even more harmful than chemical pollution.

3. Biological pollution

1. Extremely dangerous are biological pollutants caused by pathogenic microorganisms. Epidemics such as cholera, smallpox, and plague are caused by bacteria, while influenza and AIDS are caused by viruses. Insufficiently treated and neutralized domestic wastewater contains a large complex of pathogenic microorganisms causing skin, intestinal, and helminthic diseases. However, bacteria are present everywhere, and life on Earth would be impossible without these single-celled microorganisms, which help decompose and utilize organic remains.

2. Moreover, there are non-pathogenic or opportunistically pathogenic microorganisms that have chosen the human body as their biotope (habitat). Thus, the oral cavity, nose, large intestine, and vagina are habitats for many microorganisms that not only do no harm to humans but also stimulate the body's defenses, help digest food remnants, and produce vitamins. However, exceeding the normal quantity of these microorganisms under conditions unfavorable to humans (changes in ambient temperature, decreased immunity, etc.) alters the balance of microorganisms, leading to dysbacteriosis, which is itself a disease. In this case, opportunistic organisms that are normally saprophytes (such as yeast-like fungi — candida — and certain viruses) cause diseases — candidiasis and acute respiratory viral infections, respectively.

3. Pharmaceutical pollutants should be classified as a separate group. Some medications, even in therapeutic doses, have an unfavorable effect on the human body. Drugs such as aminopyrine and phenacetin are banned from production because they are pronounced carcinogens. Tetracycline-class antibiotics have an ototoxic effect. If the dosage is chosen incorrectly, by damaging the auditory nerve, they cause deafness. And taking tetracycline during pregnancy can cause deafness in a newborn child. In addition, many antibiotics damage the biocenosis of the intestines and other internal environments of the body, causing dysbacteriosis and candidiasis.

A special type of pollution includes contamination of the body's internal environment due to the consumption of non-traditional food products, including protein of microbial origin grown on various raw materials. The opportunistic fungus candida albicans is proposed for use as the producer microbe, and normal petroleum paraffins as the cultivation medium. In this case, the internal environment of the human body may be contaminated with fatty acids with an odd number of carbon atoms, which are not typical for it, amino acids atypical for the macroorganism, residual amounts of the cultivation medium, as well as antigenic determinants of the producer microbe, which can lead to various diseases, including candidiasis.

Recently, the issue of contamination of the human internal environment with foreign genetic material obtained by the body when consuming products obtained using genetic engineering technology has been widely discussed.

These products are called transgenic. They are obtained from plants into whose cell a foreign gene has been inserted. These plants are no different from their «relatives», except for one gene, which endows the plant with some new quality. In particular, thanks to the «special» gene, the Colorado potato beetle does not eat the potato, the plants do not get sick, tomatoes hang on the bush for a long time without overripening, etc.