Ecology and human diseases. Examples of some environmental diseases

Throughout the lifespan of a person, there are quite a few interesting and exciting events that have a direct impact on the lives of many generations. Since ancient times, man has sought to create more comfortable conditions for his existence, was in search of the source of all diseases, disasters and other problems that plague the planet. The life expectancy of ancient people was no more than 20-25 years, gradually this period increased and reached 30-40 years, people received hope that after 100-200 years they would be able to live for 100 or more years and not get sick and completely don't get old. And indeed, the developments of modern medicine make it possible to realize this dream, but one very capricious and righteous force - nature - will not allow it.

Man, in his impulse to transform everything and everything, completely forgot about nature - an invincible force that gave rise not only to all living things, but also to man himself. Huge industrial giants whose chimneys emit incalculable amounts of smoke poisoning the atmosphere, billions of cars, mountains of garbage that accumulate around large cities, waste that hides at the bottom of the seas and deep crevices - all this is detrimental to health. Having been born completely healthy and strong, the child after a while begins to get sick and possibly even dies. According to sad statistics, about 50 million people die every year due to poor ecology in the world, most of them are children who have not reached school age.

We list some diseases associated with poor environmental conditions:

1. Cancer. The main disease of the new century is not AIDS or other rapidly spreading diseases, such a disease is cancer - a small tumor, which is extremely rare to detect in a timely manner. A cancerous tumor appears in any part of the body, affecting the brain and spinal cord, internal organs, vision, chest, and so on. It is impossible to prevent the occurrence of the disease, as well as to reliably predict who will develop it. Thus, all of humanity is at risk.
2. Diseases accompanied by diarrhea, leading to dehydration and severe painful death. Oddly enough, in a world where sanitary conditions are prioritized for everyone else, there is simply a huge number of countries where people have absolutely no idea about hygiene, the need to wash their hands, fruits and vegetables, and wash things. And this is connected, first of all, with the upbringing of a whole separate world, which prefers to get sick and die, rather than learn something new. The cause of these diseases is the same - poisoned air, water and soil heavily watered with pesticides for the speedy growth of plants. Approximately 3 million people worldwide die from these diseases every year.
3. Respiratory infections. The main cause of respiratory diseases, that is, those that are transmitted by airborne droplets, is polluted atmosphere. That is why residents of big cities so often get the flu, pneumonia, and other diseases. It is estimated that pneumonia alone kills 3.5 million children a year.
4. Tuberculosis. Appearing with the advent of machines, this lung disease still remains incurable, although more than one hundred years have passed since its discovery. Large masses of people who work and live in the same room are most susceptible to infection, because every 5th resident of the city is in the infection zone. Statistics say that more than 3 million people die from tuberculosis caused by a lack of clean air every year.

Every year new strains of viruses and diseases appear in the world, the number of forests and fields, uncultivated and untouched areas of nature is decreasing, tuberculosis affects not only some specific people, very soon this disease will affect the entire Earth. The ongoing tree planting activities are nothing compared to how many are cut down in a day. It will take several years for a young tree to grow, during which it will be affected by drought, strong winds, storms and hurricanes. It is likely that out of hundreds of seedlings planted, only a few will reach the state of mature trees, while thousands and thousands of trees will die during this time.

Never before has a world armed to the teeth with weapons and medical supplies been as close to destruction as it is now. It is worth thinking about why high in the mountains people live for more than a hundred years, and at the same time do not get sick. Probably their secret is not in a special diet, but in remoteness from machines and technological innovations, which gradually shorten a person's days.

Svetlana Kosareva "Bad ecology and diseases of the modern world" especially for the Eco-life website.

environmentally dependent diseases- these are diseases for which the state of the environment contributes to their prevalence, the characteristics of their course, but is the only and main reason for their occurrence.

Environmentally driven diseases- this stronger term refers to a narrow range of diseases, the cause of which is quite obviously related to the environment.

Ecotoxicology deals with the identification of a spectrum of anthropogenic chemicals that affect human health, their standardization and identification of maximum allowable concentrations.

The main sources of toxicants entering the environment are:

1. natural toxicants: wind dust, volcanic eruptions, sea salt.

2.anthropogenic, associated with motor transport, industrial production, landfills, wastewater.

The concentration of toxicants in the human body stimulates the mutagenic effect, i.e. change at the gene level. The main toxicants generating the mutation are pesticides- these are organic chemical compounds resulting from the interaction of chemical fertilizers with soil microorganisms, these are genetically modified products, alien chemicals. They adversely affect digestion and assimilation of nutrients, lower the body's immune defenses.

Carcinogenic substances- These are chemical compounds that can cause malignant and benign formations in the body when exposed to it.

Lead: damages the liver, kidneys, causes chronic brain disease, mental retardation.

Chronic mercury poisoning: damage to the central and autonomic nervous system, liver, excretory organs, kidneys, digestive organs.

Cadmium: bone disease, bone fragility and fragility, has carcinogenic properties and stimulates the development of all forms of cancer and acute respiratory diseases.

Phenol: causes irritation of the mucous membranes, constant phenol poisoning destroys the kidneys and liver. Sources in the room: building and finishing materials, chipboard furniture.

Formaldehyde (a preservative in various foods): is a carcinogen; causes severe irritation to the eyes, throat, skin, respiratory tract and lungs.

Ecopathology- causes a violation of the pigmentation process, skin rashes, deterioration of well-being.

Xenobiotics- These are chemical compounds that are synthesized by man himself and have strong toxic mutagenic and carcinogenic effects.

chronic fatigue syndrome: sleep disorder, depressive state, rapid mood swings.

electromagnetic fields cause damage to the central nervous system, cardiovascular. The endocrine and immune systems can cause the growth of cancer cells.

ionizing radiation cause radiation sickness, radiation dermatitis, malignant tumors, leukemia, hereditary diseases.

Anthroecological fatigue- this is the tension of all body systems, aimed at restoring disturbed homeostasis, caused by factors of the environment changed by man.

Biological types of pollution- These are pathogenic microorganisms - viruses, helminths, protozoa, they can be in the atmosphere, water, soil, in the body of other living organisms. The peculiarity of natural focal diseases is that their pathogens exist in nature within a certain territory, out of touch with people or domestic animals (plague, typhus, tick-borne infection, malaria)

Sounds and noises of high power affect the auditory apparatus, nerve centers, can cause pain and shock.

Iatrogenic diseases- these are mental disorders that arise as a result of dioptological errors of medical workers (these are incorrect statements or actions). Treatment coincides with the treatment of neurosis.

Videoecology- This is a field of knowledge about the relationship of a person with the visible environment.

Lesson in the 11th grade "Environmental diseases"

Lesson topic: environmental diseases.

Lesson Objectives:

Give the concept of global environmental pollution, the impact on human health of heavy metals, radiation, biphenyls and emerging environmental diseases. Show ways to solve the problem of global environmental pollution. Give the concept of environmental safety of the population.

Continue developing the skills to prepare messages, analyze, compare, draw conclusions.

Education of respect for health and nature.

Equipment: photos, slides, tables.

DURING THE CLASSES

I. Organizing moment

a) Announcement of the topic of the lesson. ( . slide 1)
b) Familiarization with the lesson plan. ( . slide 2)

II. Presentation of new material

1. Global environmental pollution.

Teacher: At the beginning of the 21st century, humanity has fully felt the global environmental crisis, which clearly indicates the anthropogenic pollution of our planet. The most dangerous environmental pollutants include many inorganic and organic substances: radionuclides, heavy metals (such as mercury, cadmium, lead, zinc), radioactive metals, polychlorinated biphenyls, polyaromatic hydrocarbons. Their constant impact causes serious disturbances in the activity of the basic vital functions of the body. Probably, man has crossed the permissible ecological limits of influence on all components of the biosphere, which ultimately endangered the existence of modern civilization. We can say that a person has approached a limit that cannot be crossed under any circumstances. One careless step and humanity will "fall" into the abyss. One thoughtless move and humanity could disappear from the face of the earth.
( . slide 3)
Global environmental pollution has occurred mainly for two reasons:
1) The steady growth of the world's population.
2) A sharp increase in the course of the scientific and technological revolution in the consumption of various energy sources.

Consider the first case: . slide 4)

So, if the population in 1900 was 1.7 billion people, then by the end of the twentieth century it reached 6.2 billion people. 1950 - the share of the urban population - 29%, 2000 - 47.5%. Urbanization in Russia - 73%.
( . slide 5)Every year 145 million people are born in the world. 3 people appear every second. Every minute - 175 people. Every hour - 10.5 thousand people. Every day - 250 thousand people.

( . Slide 5) The largest urban agglomerations are: Tokyo - 26.4 million people. Mexico City - 17 million people New York - 16.6 million people Moscow - 13.4 million people

Urbanization has also affected Russia, where the share of the urban population is about 73%. In large cities, the situation with environmental pollution has become threatening (especially from vehicle emissions, radioactive contamination due to accidents at nuclear power plants).

( . Slide 6) A city with a population of 1 million people consumes 2,000 tons of food per day, 625,000 tons of water, thousands of tons of coal, oil, gas and products of their processing.
In one day, a million-strong city throws out 500,000 tons of sewage, 2,000 tons of garbage and hundreds of tons of gaseous substances. All cities of the world annually emit into the environment up to 3 billion tons of solid industrial and domestic waste and about 1 billion tons of various aerosols, over 500 cubic meters. km, industrial and domestic wastewater.(Write in notebook)

Teacher. Let's consider the second case.
Since the middle of the 19th century, as a result of the industrial and then the scientific and technological revolution, mankind has increased the consumption of fossil fuels dozens of times. With the advent of new vehicles (steam locomotives, steamships, automobiles, diesel engines) and the development of thermal power engineering, the consumption of oil and natural gas has increased significantly.
( . slide 7)
Over the past 50 years, the consumption of fossil fuels in the world has increased: coal by 2 times, oil by 8 times, gas by 12 times. So, if oil consumption in the world in 1910 amounted to 22 million tons, then in 1998 it reached 3.5 billion tons.
The basis of the socio-economic development of modern civilization is mainly energy production, based mainly on fossil fuels.
On the one hand, oil and gas have become the foundation of the well-being of many countries, and on the other, a powerful source of global pollution of our planet. Every year, more than 9 billion tons of fuel are burned in the world. tons of standard fuel, which leads to the release of more than 20 million tons of fuel into the environment. tons of carbon dioxide (CO 2 ) and more than 700 million tons of various compounds. Currently, about 2 billion tons of oil products are burned in cars.
In Russia, the total amount of pollutant emissions from all types of transport is about 17 million tons per year, with more than 80% of all emissions coming from motor vehicles. In addition to carbon monoxide, car emissions contain heavy metals, they enter the air and soil.
Mostly, about 84% carbon monoxide (CO) is emitted into the environment from vehicles. Carbon monoxide prevents the absorption of oxygen by the blood, which weakens the thinking abilities of a person, slows down reflexes, and can cause loss of consciousness and death.
Teacher. Let's move on to the next question.

2. The impact of heavy metals on the human body

A significant amount of heavy metals gets into the air and soil not only from car emissions, but also from abrasion of brake pads and wear of tires. A particular danger from these emissions is that they contain soot, which contributes to the deep penetration of heavy metals into the human body. In addition to vehicles, sources of heavy metals entering the environment are metallurgical enterprises, thermal power plants, nuclear power plants, as well as the production of fertilizers and cement.
All heavy metals can be divided into three hazard classes: we write it down in a notebook. ( . slide 8)

I class - arsenic, cadmium, mercury, beryllium, selenium, lead, zinc, as well as all radioactive metals;
II class - cobalt, chromium, copper, molybdenum, nickel, antimony;
III class - vanadium, barium, tungsten, manganese, strontium.

Effects of exposure to heavy metals on human health

Elements

Consequences of exposure to the elements

Sources

Elevated concentrations

Mercury

Nervous disorders (minamata disease).
Violation of the functions of the gastrointestinal tract, changes in chromosomes.

Pollution of soil, surface and ground waters.

Arsenic

Cancers of the skin, intonation,
peripheral neuritis.

Soil pollution.
Pickled grain.

Lead

Destruction of bone tissue, delayed protein synthesis in the blood, impaired nervous system and kidneys.

Polluted soils, surface and ground waters.

Copper

Organic changes in tissues, bone tissue breakdown, hepatitis

Pollution of soils, surface and underground waters.

Cadmium

cirrhosis of the liver, impaired renal function,
proteinuria.

Soil pollution.

The conclusions on the table are made by the student. ( . slide 10)

Findings: Heavy metals are very dangerous, they have the ability to accumulate in living organisms, increasing their concentration along the food chain, which, ultimately, poses a great danger to humans. Highly toxic and radioactive metals, getting into the human body, cause so-called environmental diseases.

3. Environmental diseases is our next question.

Teacher: Guys, you prepared material on this issue, now we will hear you. In the course of the message, you must fill in the table.

environmental diseases. ( . slide 11)

№ p-p

Disease name

Cause of the disease

How the disease manifests itself

Message from the first student. ( . Slides 12, 13, 14 (Photos of views of Japan)

In 1953, more than a hundred residents of the town of Minamata in southern Japan fell ill with a strange disease.
Their eyesight and hearing quickly deteriorated, coordination of movements was upset, convulsions and convulsions cramped muscles, speech was disturbed, and serious mental deviations appeared.
The most severe cases ended in complete blindness, paralysis, insanity, death ... In total, 50 people died in Minamata. Not only people, but also domestic animals suffered from this disease - half of the cats died in three years. They began to find out the cause of the disease, it turned out that all the victims ate sea fish caught off the coast, where industrial waste from the enterprises of the Tiso chemical concern was dumped,
containing mercury (minamata disease). ( . slide 15)
Minamata disease - disease of humans and animals caused by mercury compounds. It has been established that some aquatic microorganisms are capable of converting mercury into highly toxic methylmercury, which increases its concentration along food chains and accumulates in significant quantities in the organisms of predatory fish.
Mercury enters the human body with fish products, in which the mercury content may exceed the norm. Thus, such fish may contain 50 mg/kg of mercury; moreover, when such fish is eaten, it causes mercury poisoning when raw fish contains 10 mg / kg.
The disease manifests itself in the form of nerve disorders, headache, paralysis, weakness, loss of vision, and can even lead to death.

Message from the second student. ( . Slide 16 - photo about Japan, slide 17 - "itai-itai" disease).

Itai-tai disease poisoning of people caused by eating rice containing cadmium compounds. This disease has been known since 1955, when cadmium-containing wastewater from the Mitsui Concern entered the irrigation system of rice fields. Cadmium poisoning can cause lethargy, kidney damage, bone softening, and even death in people.
In the human body, cadmium mainly accumulates in the kidneys and liver, and its damaging effect occurs when the concentration of this chemical element in the kidneys reaches 200 µg/g. Signs of this disease are recorded in many regions of the globe, a significant amount of cadmium compounds enters the environment. Sources are: combustion of fossil fuels at thermal power plants, gas emissions from industrial enterprises, production of mineral fertilizers, dyes, catalysts, etc. Assimilation - absorption of water-food cadmium is at the level of 5%, and air up to 80%. For this reason, the content of cadmium in the body of residents of large cities with their polluted atmosphere can be ten times higher than that of rural residents. Typical "cadmium" diseases of citizens include: hypertension, coronary heart disease, kidney failure. For smokers (tobacco strongly accumulates cadmium salts from the soil) or employed in production using cadmium, emphysema is added to lung cancer., And for
non-smokers - bronchitis, pharyngitis and other respiratory diseases.

Message from the third student. ( . Slide 18 - photo about Japan, slide 19 - Yusho disease).

Yusho disease - Poisoning of humans by polychlorinated biphenyls (PCBs) has been known since 1968. In Japan, in a rice oil refinery, befinils from refrigeration units got into the product. The poisoned oil was then marketed as food and animal feed. At first, about 100 thousand chickens died, and soon the first symptoms of poisoning appeared in people. This was reflected in changes in skin color, in particular darkening of the skin in children born to mothers who suffered from PCB poisoning. Later, severe lesions of internal organs (liver, kidneys, spleen) and the development of malignant tumors were discovered.
The use of some types of PCBs in agriculture and public health in some countries to control the vectors of infectious diseases has led to their accumulation in many types of agricultural products, such as rice, cotton, vegetables.
Some PCBs enter the environment with emissions from waste incineration plants, which poses a health hazard to urban residents. Therefore, many countries limit the use of PCBs or use them only in closed systems.

Message 4 student. ( . Slides 20-21 - photo about Altai)

Disease "yellow children" - the disease appeared as a result of the destruction of intercontinental ballistic missiles, which led to the release of toxic components of rocket fuel into the environment: UDMH (unsymmetrical dimethylhydrazine or gentyl) - the main component of rocket fuel, as well as nitrogen tetroxide (both belong to the first hazard class). These compounds are highly toxic; they enter the human body through the skin, mucous membranes, upper respiratory tract, and gastrointestinal tract. As a result, children began to be born with
pronounced signs of jaundice. The incidence of newborns increased by 2-3 times. The number of newborns with lesions of the central nervous system has increased. Infant mortality has risen. Due to the release of these substances, skin "burns" appeared - pustular diseases that can appear after swimming in local rivers, hiking in the forest, direct contact of naked parts of the body with soil, etc. ( . Slide 23 - yellow children disease).

Message 5 student. ( . Slide 23 - drawing of the Chernobyl accident).

"Chernobyl disease" ( . Slide 24 - "Chernobyl disease")

April 26, 1986 An explosion occurred at the 4th power unit of the Chernobyl nuclear power plant. The release of radionuclides amounted to 77 kg. (Hiroshima - 740 gr.). 9 million people were affected. The area of ​​pollution was 160 thousand km. sq. The composition of radioactive fallout included about 30 radionuclides such as: krypton - 85, iodine - 131, cesium - 317, plutonium - 239. The most dangerous of them was iodine - 131, with a short half-life. This element enters the human body through the respiratory tract, concentrating in the thyroid gland. The local population had symptoms of the "Chernobyl disease": headache, dry mouth, swollen lymph nodes, oncological tumors of the larynx and thyroid gland. Also, in the areas affected by the accident at the Chernobyl nuclear power plant, the incidence of the cardiovascular system has increased, outbreaks of various infections have become more frequent, and birth rates have significantly decreased. The frequency of mutations among children increased by 2.5 times, anomalies occurred in every fifth newborn, about a third of children were born with mental disorders. Traces of the Chernobyl "event"
in the genetic apparatus of mankind, according to doctors, will disappear only after 40 generations.

( . slide 25)

Teacher. How can the impact of industrial pollution on the environment be reduced?

( . slide 26)

1. Use of treatment facilities
2. Non-traditional energy sources.
3. Replacing old technologies with new ones.
4. Rational organization of traffic.
5. Prevention of accidents at nuclear power plants and other industrial enterprises.

Teacher. Let's move on to the last question.

4. Environmental safety of the population

Teacher. The issue of environmental safety of the population worries each of us. What is environmental security? We look at the slide, write out the definition and basic laws. ( . slide 27)

The ecological safety of the population is the state of protection of the vital ecological interests of a person and, above all, his rights to a favorable environment.

Human health currently also depends on the state of the environment. "You have to pay for everything" says one of Barry Commoner's laws. And we pay with our health for the environmental problems we have created. In recent years, in many countries, due to the increase in the number of environmentally caused diseases, special attention has been paid to the legal issues of environmental protection. Important federal environmental laws have been adopted in our country: “On the Protection of the Environment” (1991), the Water Code of the Russian Federation (1995), “On the Radiation Safety of the Population” (1996), “On the Sanitary and Epidemiological Well-Being of the Population” (1999). The "Concept of the transition of the Russian Federation to sustainable development" was developed in 1996. In solving environmental problems, international cooperation is of great importance.

Conclusion ( . slide 28)

Nature has been and always will be stronger than man. She is eternal and infinite. If you leave everything as it is, then soon after only 20-50 years, the Earth will respond to humanity with an irresistible blow to destruction!

Reflection ( . Slides 29, 30 are fun drawings).

III. Fixing the material

( . Slides 31-35). Checking the filling of the table "Environmental diseases".

IV. Homework

Learn the material in the table.

Literature:

1. Vovk G.A. Ecology. Textbook for students 10 cells. educational institutions.
Blagoveshchensk: Publishing house of BSPU, 2000.
2. Vronsky V.A. environmental diseases. Journal "Geography at School No. 3, 2003.
3. Korobkin V.I., Peredelsky L.V. Ecology. Rostov n-D: publishing house "Phoenix", 2001.
4. Kuznetsov V.N. Ecology of Russia. Reader. M: JSC "MDS", 1996.
5. Rozanov L.L. Geoecology. Textbook 10 -11 cells. elective courses. Bustard, 2005.

Biologists and economists have recently begun to use a new term - "ecosystem services", which refers to the many ways in which nature supports human activities. Forests filter our drinking water, birds and bees pollinate crops, and both services are of high economic and biological value.

If we do not understand the laws of the natural ecosystem and do not take care of it, then the system will cease to provide the “service” we need and even begin to persecute us in forms that we still have very little idea of. An example is the emergence of new infectious diseases, in which most epidemics - AIDS, Ebola, West Nile, acute respiratory syndrome (SARS), Lyme disease, and hundreds of others that have occurred in recent decades, did not happen by themselves.

As it turns out, the disease is largely environmentally conditioned. 60% of human infectious diseases are zoonotic, that is, they originate from animals. And more than two-thirds of them originate in the wild.

Several teams of veterinarians and environmentalists, together with medical scientists and epidemiologists, are making efforts at a global level to understand the "ecology of disease." Their work is part of a project called Predict, which is funded by the US Agency for International Development. Experts are trying to understand how, based on knowledge of man-made changes in the landscape, for example, the construction of a new farm or road, it is possible to predict exactly where new diseases for humanity will penetrate to us, and how to detect them in time, that is, before they have time. spread. Researchers take samples of blood, saliva and other biomaterials from animals of those species that pose the greatest threat to the spread of infection in order to compile a kind of catalog of viruses: having it, it will be possible to quickly identify the virus if it infects a person. Experts are looking for ways to treat forests, their fauna and domestic animals that would prevent the emergence of diseases from forest areas and their growth into new pandemics.

This is not only about health care, but also about the economy. The World Bank has calculated that a ferocious flu epidemic, for example, could cost the global economy $3 trillion.

The problem is exacerbated by poor livestock conditions in poor countries: this factor can significantly increase the threat of the spread of infections carried by wild animals. Recently, the International Institute for Animal Research published information that annually more than 2 million people die from diseases transmitted to humans from wild and domestic animals.

The Nipah virus in South Africa and the closely related Hendra virus in Australia (both from the genus Henipah) are the most recent examples of how ecosystem disruption can lead to the spread of disease. The source of these viruses are flying foxes (Pteropus vampyrus), also known as fruit bats. They eat very sloppily and this is an important factor in the transmission scenario. Resembling Dracula in their appearance, tightly wrapped in a webbed cloak, they often hang upside down and eat fruits: the pulp is chewed, and the juice and seeds are spit out.

Flying foxes and Henipah viruses originated millions of years ago and co-evolved, so that the host rarely becomes seriously ill when exposed to a virus, except perhaps the flying fox equivalent of our cold. When the virus breaks through to species that are not its traditional symbiont, something similar to the scenario of a horror movie can happen, as happened in rural Malaysia in 1999. Apparently, a flying fox dropped a piece of chewed fruit pulp into a pigsty located in the forest. The pigs contracted the virus, amplified it, after which it passed to humans. Its lethal power was astounding: of the 276 people infected in Malaysia, 106 died, and many of the survivors were left with lifelong disabilities suffering from neurological complications. There is no vaccine or cure for Henipah infection. Since the first outbreak of the disease, 12 more have occurred in South Asia, albeit on a smaller scale.

In Australia, where 4 people and several dozen horses died from the Hendra virus, the scenario was different: the expansion of the suburbs led to the fact that infected bats, which have always inhabited exclusively forests, have chosen yards and pastures. If Henipah viruses have evolved to be ready to be transmitted through casual contact, then you have to worry about whether he can leave the jungle and spread first to Asia and then to the world. "Nipah is leaking out and we're seeing small clusters of cases so far, but it's only a matter of time before a strain will emerge that can spread very effectively in humans," says Jonathan Epstein, a veterinarian with the EcoHealth Alliance, New York. York-based organization that studies the environmental causes of disease.

Emerging infectious diseases are either new types of pathogens, or old but mutated, as is the case with influenza every year. For example, humans acquired AIDS from chimpanzees in the 1920s, when they were killed and eaten by African hunters of wild animals.

Throughout history, diseases have emerged from forests and wildlife to make their way into human populations: plague and malaria are just two examples of such infections. Over the past 50 years, however, the number of re-emerging diseases, according to experts, has quadrupled, mainly due to the ever deeper penetration of humans into the wild, especially in the infectious “hotspots” of the planet, most of which are located in tropical regions. . Thanks to the possibilities of modern air transport and the stable demand for wild animals, the likelihood of a large-scale outbreak of any infectious disease in large settlements is quite high.

The key to predicting and preventing a future pandemic, experts say, is understanding the so-called “protective effect” of nature undisturbed by human intervention. For example, scientific analysis shows that in the Amazon, deforestation of just 4% of forests has led to a 50% increase in malaria cases, because mosquitoes that transmit the infection multiply much more actively when there is a combination of sunlight and water, that is, in the conditions created in the areas of deforestation. . Making ill-conceived actions in relation to forests, a person opens a Pandora's box - and this kind of cause and effect is studied by a newly created team of specialists.

Public health experts are beginning to incorporate the environmental factor into their population health models. Australia, for example, is launching a massive multi-million dollar Hendra virus and bat ecology project.

However, the introduction of human civilization into the tropical landscape is not the only factor contributing to the emergence of new infectious diseases. The West Nile virus came to the United States from Africa, but spread because one of its favorite hosts is the robin, which thrives in America, in the edge of clearings and agricultural fields. Mosquitoes that spread the disease find robins particularly attractive. "The health impact of the virus in the United States has been so significant because it uses species that get along well with humans," says Marm Kilpatrick, a biologist at the University of California at Santa Cruz. Because of the leading role in the spread of this disease, the robin is called a "super-carrier".

The scourge of the American east coast, Lyme disease, is also largely a product of human intervention in the environment, namely, the result of the reduction and fragmentation of extensive forest areas. The human invasion has scared away natural predators - wolves, foxes, owls and hawks. This resulted in a five-fold increase in the number of white-footed hamsters, which are an excellent "reservoir" for Lyme bacteria, possibly because they have a very weak immune system. In addition, they take very poor care of their fur. Possums and gray squirrels comb out 90% of the tick larvae that spread the virus, and hamsters destroy only 50%. “In this way, hamsters produce a huge number of infected pupae,” says Richard Ostfeld, a specialist in Lyme disease.

“When our actions in an ecosystem, such as tearing apart a single forest area and plowing the vacated area into farmland, damage biodiversity, we get rid of those species that perform a protective function,” says Dr. Ostfeld. “There are several species that are reservoirs of infection, and quite a few that are not. By intervening, we encourage those who play the role of reservoirs to breed.

Dr. Ostfeld observed the emergence of two infectious diseases carried by ticks - piroplasmosis (babesiosis) and anaplasmosis - and he was the first to raise the alarm about the possibility of their spread.

The best way to prevent new disease outbreaks, experts say, is through a worldwide program they call the "One Health Initiative," which includes the work of more than 600 scientists and other professionals and promotes the idea that the health of people, animals and ecosystems as a whole are inextricably linked. , and when planning certain innovations affecting nature, they must be approached as a whole.

“This does not mean that you need to leave the virgin forests virgin and not let people go there,” explains Simon Anthony, a molecular virologist at the Center for the Study of Infection and Immunity at Columbia University: “But you need to understand how to do it without harm. If we can find the mechanism that triggers the occurrence of the disease, we will be able to make changes in the environment without negative consequences.”

This is a task of enormous scale and complexity. According to experts, today science has studied approximately 1% of all viruses that live in the wild. Another complicating circumstance is that wildlife immunology as a science is just beginning to develop. Raina C. Plowright, a biologist at Pennsylvania State University who studies disease ecology, found that outbreaks of Hendra virus in flying foxes in rural areas are quite rare and much higher in urban and suburban animals. She hypothesizes that urban bats become sedentary and are less exposed to the virus than wild ones, and therefore get sick more easily. This means that an increasing number of flying foxes - whether as a result of poor nutrition, loss of natural environment, or for other reasons - become infected themselves and bring the virus into the yard to humans.

The fate of a future pandemic may depend on the work of the Forecast project. EcoHealth and its partners, UC Davis, the Wildlife Conservation Society, and the Smithsonian Institute for Global Predictions in Virology, study and catalog viruses that infect tropical wildlife. The focus is on primates, rats and bats, which are the most likely vectors of human diseases.

Project Prognoz researchers are monitoring sites where the existence of deadly viruses is an established fact and man is breaking into the forest zone, as is happening along the new highway connecting the Atlantic coast with the Pacific coast through the Andes in Brazil and Peru. “By mapping forest invasion sites, you can predict where the next outbreak might occur,” says Dr. Dazak, president of EcoHealth. roads are being built. We talk to people living in these zones and explain to them that their activities are very risky.”

It may also be necessary to speak to traditional game hunters, as well as those who build farms in areas that are the natural habitat of bats. In Bangladesh, where the Nipah virus has caused outbreaks on several occasions, flying foxes have been found to visit collector containers of date juice that people have been drinking. The containers were covered with bamboo mats (costing 8 cents each) and the source of the disease was eliminated.

EcoHealth specialists also organized luggage scanning at airports to check imported exotic animals, which are highly likely to be carriers of viruses that are fatal to humans. EcoHealth has a special PetWatch program designed to warn fans of keeping exotic pets brought to market from wild forests in infectious hot spots of the planet.

Dr. Epstein, EcoHealth veterinarian, believes that the knowledge gained over the past few years about the ecology of disease allows us to worry a little less about the future. “For the first time in history, we are taking coordinated action from 20 countries around the world to develop a system of timely warnings about the potential threat of outbreaks of zoonotic infections,” he says.

Jim ROBBINS

A special group of diseases, which are called environmental diseases (not to be confused with endemic), have recently been discovered. They are caused by substances alien to organisms - xenobiotics - mi (from the Greek. Xenos - alien and bios - life), among which the most negative impact is exerted by heavy metal ions(Cadmium, lead, Mercury, etc.) And some binary compounds of non-metals (sulfur (IU) oxide S02 and nitrogen (IU) oxide N02).

Metallic mercury and its vapors, which are extremely toxic chemicals, are among the most common "metal" environmental pollutants. Releases to water are especially dangerous, because as a result of the activity of microorganisms that inhabit the bottom, a highly toxic compound soluble in water is formed, which causes Minamata disease. (Note! If a mercury thermometer breaks in your home, you should carefully collect all the balls of mercury on a piece of paper, and cover the cracks and uneven floors with sulfur powder. Sulfur easily reacts chemically with mercury, forming a harmless HgS compound.)

Cadmium, its compounds and vapors are also acutely toxic substances that are easily absorbed into the blood, affect the central nervous system, liver and kidneys, and disrupt metabolism. Chronic poisoning in small doses (itai-itai disease) leads to anemia and bone destruction. Symptoms of acute poisoning with Cadmium salts are accompanied by sudden vomiting and convulsions.

Lead and its compounds are also very toxic. Once in the human body, they accumulate (from lat accumulation - accumulation) in the bones, causing their destruction, and the atoms of this element can accumulate in the renal tubules, causing a violation of the excretory function. Lead compounds are widely used in the production of dyes, paints, pesticides, glass products, and also as an additive to gasoline to increase the octane number, and therefore poisoning with this element occurs more often. Since car emissions contain lead compounds, now they have simply covered the entire earth's surface, even reaching Antarctica, where there have never been cars.

Perhaps the most famous outbreak of environmental disease in our country was in the late 80s pp. 20th century a case in the city of Chernivtsi, when outwardly healthy children of 2-3 years of age began to suddenly lose their hair and in one night they simply went bald. The cause of this disease, which is called intoxication aplecia, was quickly established - salt poisoning of Thalia, a very dangerous xenobiotic. However, it is still unclear where this chemical element came from in such quantities. It should be said that all over the world, and in Ukraine in particular, there are quite often outbreaks of diseases unknown to medicine, caused by the action of various kinds of unnatural substances on the body.

What is acid rain. Powerful environmental pollutants are various oxides of sulfur and nitrogen, which are released into the atmosphere mainly when coal is burned. Substances are dangerous not only because they can cause allergies and asthma, but also because of acid rain. Reacting with atmospheric water (often under the influence of solar radiation), sulfur oxides are converted into solutions of acids - sulfite (S02 + H20 \u003d H2S03), sulfuric (S03 + H20 \u003d H2S04), and nitrogen oxides - nitrous and nitric (2N02 - h H20 = HN03 - h HN02) acids. Then, together with snow or rain, they fall to the ground. Acid rain destroys forests and crops, destroys life in water bodies, increasing their acidity to such a level that plants and animals die in them.

Thus, in the production process and for energy production, a huge amount of waste substances (soot, phosphorus, carbon monoxide, nitrogen oxides and

Sulfur, various compounds of metallic elements, etc.), the mass of which in just a year on Earth is millions of tons. Living beings have never encountered most of these compounds, and therefore they cannot utilize them - use them for their own needs. Whereas their accumulation inevitably leads to the gradual destruction of the natural environment and is detrimental to all living things. Since modern civilization cannot do without the production of ever new cars, aircraft, tankers, the construction of factories, residential neighborhoods and just cottages, and the transition to environmentally friendly production of matter and energy is still nothing more than a project of the future, then there is a need to quota production waste , limiting their free release. To do this, each country is given a quota, according to which it will be able to pollute the environment for a certain number of tons of emissions per year. But even this idea, which, of course, is only a half-measure, does not find real support in the governments of the most developed countries, since in this case a sharp drop in production is expected.