Protection from biological hazards and harmful factors. Biological hazard and agents that cause it

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MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION

Federal state budget educational

Institution of higher professional education

« KUBAN STATE UNIVERSITY"

(FSBEI HPE "KubSU")

Essay

by discipline

Life safety

On the topic of:

“Biological hazards associated with plants; joint venturepersons and means of protection against them"

Completed:Blazhnov Anton Yurievich

1st year student of general education majoring in economics

Group 109

Signature__________________

Teacher: Melnik N.A.

Rating _________Date_________________

Signature____________

Krasnodar-2012

1. Introduction

2. General characteristics

3. Classification of poisonous plants

4. Types of poisonous plants and symptoms

5. Geographical distribution of poisonous plants

6. 1.How to avoid biohazards

2. Methods of prevention when exposed to biological hazards

7. Conclusion

8. Sources

poisonous plant biological hazard

1. Introduction

In the life process, a person is inextricably linked with his environment, while at all times he has been and remains dependent on his environment. It is through it that he satisfies his needs for food, air, water, material resources and recreation.

Habitat- the environment surrounding a person, determined by a combination of factors (physical, chemical, biological, informational, social) that can have a direct or indirect immediate or remote impact on the life of a person, his health and his offspring.

Man and the environment are constantly in interaction, forming a constantly operating system “man - environment.”
Impacts that can cause negative disturbances in the well-being and health of people are called hazards. Danger is a property of elements of the “person-environment” system that can cause harm to people, natural environment and material resources.

Biological hazards can have different effects on humans - mechanical, chemical and biological. Biological hazards result in various diseases and injuries of varying severity, including fatal ones.

Not only microorganisms, but also macroorganisms - plants - pose a danger to humans.

The object of study is biological hazards and nature, modern world and their harmonious existence.

Item- a man in a world of danger.

Purpose of writing the work- study of biological hazards associated with plants and ways to combat them.

In accordance with this, the purpose of the work is the theoretical study of biological hazards.

2. General characteristics

There are about 10 thousand species of poisonous plants known on earth.

Plant poisons have different effects on the human body. Some affect the central nervous system: henbane, datura, poppy; others - respiratory organs: spurge, wolf's bast, dome; third - the cardiovascular system: lily of the valley, raven's eye. Some plants have poisonous bark and fruits, but the leaves and flowers are harmless (buckthorn). Sometimes, on the contrary, the poison is contained in the flower or in the roots (bath).

People and animals react differently to plant poisons. Some people are hypersensitive to poisons. A simple touch is enough to poison a person.

Some mushrooms are poisonous. The most poisonous mushroom in the world is the toadstool. This mushroom poses a mortal danger to humans.

3 . Classification of poisonous plants

Plants containing specific substances that, at a certain exposure (dose and duration of exposure), can cause illness or death in humans or other animals. In the plant world there are thousands toxic substances, which are usually divided into several groups depending on their chemical nature. For example, alkaloids, glycosides, phytotoxins, photosensitizing pigments, saponins, mineral poisons, etc. are isolated. They can also be classified according to the clinical picture of poisoning. There are, say, neurotoxins, liver and kidney poisons, substances that irritate the digestive tract, cause respiratory arrest, damage the skin, and cause developmental defects. Sometimes one substance belongs to several chemical classes at once or acts on several organ systems. The toxicity of at least 700 North American plant species is well established. They are known in all major taxonomic groups, from algae to monocots. There are poisonous unicellular ferns, gymnosperms and angiosperms; sometimes poisoning is caused by mold, smut or rust fungi present on plants or in plant foods. Although bacteria and fungi are now classified as independent kingdoms of organisms, some of them are traditionally considered together with poisonous plants.

Poisoning and other reactions. A distinction is made between poisoning and infection caused by bacteria or fungi. Infectious agents settle in another organism, destroying tissues and multiplying at their expense. Poisonous organisms secrete toxic substances, which act regardless of whether the organism that formed them is alive or dead, whether it is present or no longer present at the time of poisoning. For example, botulinum toxin produced by the bacterium Clostridium botulinum causes intoxication (botulism), even if the bacterium itself was killed during sterilization of products. Poisoning should also be distinguished from allergic reactions that occur in animals when they are exposed to special substances - allergens, present, in particular, in some plants. Thus, a skin rash that occurs when touching rooting sumac (Rhus toxicodendron, according to another classification - Toxicodendron radicans) or related species is an allergic reaction to certain substances present in this plant. Repeated contact with an allergen can increase sensitivity to it. Redness and irritation of the skin are caused by certain substances without sensitization, for example the milky juice of euphorbia (Euphorbia spp.) or the secretion of stinging nettle hairs (Urtica spp.). Local sunburn, sometimes persisting for many months as a dark pigment spot, can occur due to exposure to psoralen on damp skin. This phenolic compound is present in parsnips (Pastinaca sativa), white ash (Dictamnus albus), lime peel (Citrus aurantifolia) and several other plants.

Exposure to toxic compounds. The nature of poisoning depends on the reactions that occur in the animal’s body, as well as on the extent to which the poison accumulates in the body and how it is removed from it. In some cases, a toxic substance is formed in animal tissues from a harmless precursor present in the plant. Thus, when eating wild plum leaves (Prunus spp.), cyanide is released from the harmless glycosides they contain; Nitrates present in feed or food are converted by the animal's body into the much more toxic nitrites. However, in most cases, plant toxins exert their effects without prior chemical change. When eaten, the poison enters primarily into the oral cavity. Some irritants , for example arum plants (Dieffenbachia, etc.), act mainly at this level. The poison then passes to subsequent parts of the digestive system (without necessarily damaging them) and can be absorbed or excreted. After absorption, it primarily enters the portal vein of the liver and the liver itself. There its chemical detoxification can occur, i.e. conversion to a harmless form and excretion in bile; on the other hand, it can cause damage to liver cells or simply pass through it and enter other organs and tissues with the blood - in this case, damage to the entire body or only some structures sensitive to the poison is possible. Since poisons enter primarily the digestive system, its anatomical and physiological characteristics in a given animal species significantly influence the manifestation of the toxic effect of a particular substance. For example, in birds, food passes through the crop and gizzard before absorption, and in ruminants, in particular cows, goats and sheep, it is first (in the rumen) exposed to the action of microbial enzymes and only then is it actually digested and absorbed. Both birds and ruminants in this sense differ sharply from “one-gastric” animals, such as pigs and horses, in which plant material begins to be digested in the stomach almost immediately after ingestion. The ease of removing eaten food by vomiting also varies depending on the type of digestive system. Ruminants are able to get rid of only part of the contents of the first section of the stomach - the rumen - in this way, while humans, dogs and pigs can quickly and efficiently empty this entire organ. A horse also vomits, but due to the structure of its soft palate, the vomited material ends up in the trachea, which usually results in death from suffocation. Fortunately, many poisons themselves stimulate the vomiting reaction. The level of toxicity can be expressed as the amount of plant material capable of poisoning a given animal, as a percentage of the latter's weight. So, if it is equal to 0.1%, it means that an animal weighing 100 kg will be poisoned by eating 100 g of poisonous food. For most poisonous species, toxicity ranges from 0.01 to 1%. In practice, this means that poisoning from not the most dangerous plants will occur only if you take a mouthful of leaves or fruits several times. However, in the case of some plants, much smaller amounts can cause serious health damage and even death. Examples of this are the fruits of the wolfberry (Daphne spp. ), seeds of the dangerous abrus (Abrus precatorius) or castor bean (Ricinus communis). The last two species are considered the most poisonous of all seed plants. Their toxins are polypeptides of similar structure that suppress protein synthesis in the intestinal wall. As a result, it collapses and ceases to function. At the same time, castor bean seeds are a source of safe castor oil. An example of another kind is bracken fern (Pteridium aquilinum): poisoning of livestock with it is noted only after eating this plant in an amount approximately equal to the weight of the animal itself.

Prevention and treatment. Poisoning occurs most often in children under five years of age. These cases are the sixth most common poisoning in this age group overall and are caused almost exclusively by cultivated species. Poisonings in adults are usually caused by wild plants collected for food. These poisonings are usually more dangerous. Plant poisoning affects approximately 15,000 people every year. This figure has not been determined for domestic animals, but it is likely much higher.

3. Common Poisonous Plants

It is difficult to say which plants are the most poisonous, so the data below is far from complete and, naturally, does not cover all species that can cause poisoning. Additionally, only plants from the mainland US are considered here.

Indoor and garden-decorative herbaceous plants. Many bulbous species close to lilies contain dangerous concentrations of alkaloids or other biologically active substances in their bulbs. Examples include oriental hyacinth (Ornithogalum umbellatum), snowdrop (Galanthus nivalis) and oriental hyacinth. Colchicum autumnale and Gloriosa superba contain colchicine, a valuable medicinal substance used to treat gout; in large doses it causes nausea, vomiting, severe diarrhea, hair loss, bleeding disorders and kidney damage. Representatives of the amaryllidaceae family (Amaryllidaceae), which includes, in particular, daffodils (Narcissus spp.) and amaryllis (Amaryllis spp.), are rich in the alkaloid lycorine, which stimulates the vomiting center in the brain. Poisoning occurs when the bulbs of all the plants listed above are mistaken for onions. Another close relative of lilies, May lily of the valley (Convallaria majalis), contains a cardiac glycoside in fairly high concentrations, which can cause an effect similar to an overdose of digitalis preparations. The latter are obtained from the purple or red foxglove (Digitalis purpurea), which grows wild in the Pacific Northwest of the United States and has become naturalized in other regions. In small doses, its glycosides stimulate the work of weakened heart muscle, but in case of overdose they lead to arrhythmias and blockade electrical conductivity heart, necessary for its normal contractions. Many plants of the poppy family contain alkaloids that are hazardous to health. The most striking example is the soporific poppy (Papaver somniferum), from which morphine is obtained. This beautiful garden plant was once widely grown in the United States, but its cultivation is now illegal. Oriental poppy (P. orientale) contains chemically similar alkaloids, but they have a different effect. The same can be said about the garden “broken heart”, or magnificent dicentra (Dicentra spectabilis), and its wild relatives - dicentra cucullaria (D. cucullaria) and dicentra canadensis (D. canadensis) from a family very close to poppies. Black hellebore (Helleborus niger), a member of the ranunculaceae family, blooms in late autumn or immediately after the snow melts in spring. Like buttercups (Ranunculus spp.), it contains a biologically active substance that, when consumed, causes severe irritation of the gastrointestinal tract. The rhizomes of many, if not all, iris spp., which are fleshy and very attractive to children, produce a similar effect. Many arums are rich in highly irritating substances to the mucous membrane, such as Dieffenbachia spp., Philodendron spp., Symplocarpus foetidus, and Arisaema spp., as well as most milkweeds (Euphorbia spp. .). Some species of Phoradendron are dangerous. Chewing Dieffenbachia can cause the tissues in the mouth to become so swollen that it causes temporary loss of speech. The milky sap of euphorbia can cause burning and blistering on the skin, and if it gets into the eyes, it can cause temporary blindness. Larkspur, or spur, resembles lupine, although these plants are not closely related. However, both genera contain dangerous alkaloids. The larkspur (Aconitum napellus) is from the same family as the larkspur and is close to it in chemical composition. In Europe, this species is considered one of the most poisonous garden plants.

Decorative trees and shrubs. Some shrubs, highly valued as ornamental species and therefore grown in gardens and near houses, are dangerous poisonous plants. An example is the common oleander (Nerium oleander), grown outdoors throughout the western and southern United States and sometimes indoors. The beautiful evergreen foliage and wood of this species contain a cardiac glycoside, similar in action to the digitalis preparations mentioned above. Experiments show that if one leaf is chewed properly and swallowed, the dose of poison released from it in the digestive tract will be almost lethal for an adult. In the eastern United States, very poisonous yew (Taxus baccata) and pointed yew (T. cuspidata) are often found. They are especially loved to be planted near houses. The leaves and seeds of both species contain a substance that can quickly lead to cardiac arrest, although the red pulp of their “berries”, formed in the summer on female plants, is considered harmless. Other shrubs with mildly to moderately poisonous leaves include common privet (Ligustrum vulgare) and evergreen boxwood (Buxus sempervirens). Among plants of the heather family, Kalmia spp., Rhododendron spp., Pieris japonica and Leucothoe davisiae contain in their leaves a substance that causes severe nausea, vomiting, depression, slow heart rate, and a drop in blood pressure and death at high doses. Nectar from heather flowers also leads to a similar pattern of intoxication. Poisoning from the leaves of Kalmia and other ornamental shrubs is relatively common in livestock and zoo animals. However, wild deer seem to be able to eat large quantities of such food without any harm. This is explained by the fact that they consume it in small doses: stomach discomfort forces them to temporarily stop eating these plants, so it does not reach lethal levels of the toxin in the body. Green, black, white or red - depending on the type - the fruits of wolfworts, or wolfberries (Daphne spp.), attract children and have a pronounced irritating effect. A few berries taken into the mouth cause a severe burning sensation, and if they are swallowed, a similar sensation occurs in the esophagus and stomach. Possible death. It is dangerous to eat the seeds and beans of wisteria (Wisteria spp.) and golden shower (Laburnum anagyroides) from the legume family. Wisteria fruit causes severe stomach upset, and golden shower fruit contains a nicotine-like neurotoxin that causes vomiting, increased heart rate, and muscle relaxation that can lead to suffocation. Appetizing to look at (especially for children), the seeds of the common horse chestnut (Aesculus hippocastanum) contain a weak poison. Other representatives of this genus are much more dangerous and have repeatedly led to the death of domestic animals.

Garden crops. You can also be poisoned by some parts of ordinary garden plants, primarily potatoes, tomatoes and rhubarb. The toxic substances contained in potatoes (Solanum tuberosum) are solanine glycoalkaloids, also characteristic of wild nightshades (Solanum spp.) and concentrated in green shoots. Thus, potato tops cannot be fed to livestock, and sprouted eyes and green spots must be removed from tubers intended for food. Children appear to be significantly more sensitive to solanine than adults, although fatal poisonings are rare. Symptoms of intoxication are the same as for “stomach flu”: nausea, headache, sore throat and diarrhea, sometimes bloody. The tomato (Lycopersicon esculentum) also belongs to the nightshade family, and according to some observations, its greens can be poisonous to animals. In rhubarb, only the leaf petioles are usually eaten. The leaf blade, which, as a rule, cannot be found on sale, contains a lot of oxalic acid. Its high concentrations lead to irritation, blockage and even rupture of the renal tubules, where crystals of its salts - oxalates - precipitate.

Fruit trees. Parts of some fruit trees are poisonous. An example is Ford's tung, or Chinese tung (Aleurites fordii), bred for its oil seeds, which tourists sometimes confuse with the edible "nuts" of the hazel pecan. The result is vomiting, severe stomach cramps and diarrhea. Raw pits of plums, peaches and apricots (Prunus spp.), as well as seeds of apple and pear trees (Pyrus spp.), contain cyanide, but if eaten, they are not eaten in such quantities as to cause serious poisoning.

Plants of forests and forest belts. Common poisonous species in planted forests are wild plums (Prunus spp.), whose leaves are a source of cyanide, black locust (Robinia pseudoacacia) and elderberry (Sambucus spp.). The inconspicuous perennial grass Eupatorium rugosum is known for its specific poison. If this grass gets into livestock feed, the animals' cellular metabolism is disrupted and a characteristic symptom appears, popularly called “shaking.” In cows, the poison easily penetrates into the milk; consumption of such milk causes a similar clinical picture, known as “milk sickness”.

Plants of swamps and wet places. To especially dangerous species, growing in swamps and along the banks of fresh water bodies, include spotted weed (Cicuta maculata) and lobelia (Lobelia spp.). Vecha, which is often confused with parsnips, has a fleshy, branched root that contains a powerful poison that causes convulsions and death. Wild lobelias are rich in pyridine alkaloids, similar in action to nicotine.

Herbs of meadows, clearings and forest edges. Many poisonous species are found on fallow lands, pastures and slopes overgrown with sparse bushes. Bracken fern (Pteridium aquilinum) contains an enzyme that breaks down thiamine (vitamin B1) in plant feed, leading to corresponding vitamin deficiency in horses after a few weeks. Cattle are not at risk of thiamine deficiency, but another, not yet fully identified, substance in bracken causes symptoms in these animals that resemble the picture of radiation sickness. The effect depends on the dose and is expressed in the fact that the bone marrow is destroyed and in various organs there are cancerous tumors. Green hellebore (Veratrum viride) contains highly active alkaloids. A closely related species, California hellebore (V. californicum), which grows on mountain pastures, causes fetal malformations in sheep that ate this grass on the 14th day of pregnancy. The period of sensitivity of the embryo to the poison of this plant is only about 6 hours. Its action is reminiscent of the notorious drug thalidomide, which - before it was banned - managed to lead to the birth of many babies with congenital deformities. Datura stramonium contains tropine alkaloids, in particular hyoscine (scopolamine) and atropine, which have a strong effect on the central nervous system, often with fatal outcome. In meadows and forest edges there are nightshades (Solanum spp.), which were already mentioned above. Spotted hemlock (Conium maculatum) is very similar in appearance to wild carrot (Daucus carota): both plants belong to the umbrella family and have a fleshy taproot. All parts of hemlock contain an alkaloid that paralyzes the respiratory muscles. It was the juice of this plant, and not the hemlock (i.e., the milestone), as is usually believed, that Socrates was poisoned. St. John's wort (Hypericum perforatum) is an inconspicuous meadow grass whose leaves are covered with tiny transparent dots. These are glands that contain a substance that causes photosensitization of the skin: if it penetrates its capillaries, then under the influence of sunlight a burn occurs in this place. This effect is fraught with serious consequences for light-skinned grazing animals: deep burns on the lips, eyelids and ears are possible. Sometimes sweet clover - white (Melilotus alba) and yellow or medicinal (M. officinalis) - are grown as a cover or soil-improving crop. Under the influence of moisture and the fungus developing in damp conditions, the harmless aromatic substance of the plant - coumarin - turns into an anticoagulant, i.e. an anti-clotting agent. Regular consumption of sweet clover hay by livestock is fraught with incessant bleeding from any, even the most insignificant external or internal wound. In medicine, anticoagulants are used to fight blood clots.

Ruderal species. Ruderal, i.e. literally “garbage”, grasses are typical for landfills, vacant lots, roadsides and similar places, usually rapidly overgrown with the so-called. weeds Among the poisonous species, one can find here the thyroid podophilus (Podophyllum peltatum), the roots and leaves of which contain a substance with a mild laxative effect, as well as horsetail (Equisetum arvense), the tissues of which, like bracken, are rich in an enzyme that destroys thiamine. A widespread tall (up to 3 m) grass with a thick, succulent stem is American commonweed (Phytolacca americana). Some of its parts, especially the roots, contain a strong laxative, but more importantly, all of them are capable of causing characteristic changes in the blood: a certain type of white blood cell increases in size and acquires other abnormal characteristics. Most often, this effect is observed if the plant is eaten, but it also occurs when you simply hold it in your hands for a long time and the poison penetrates the body through intact (undamaged) skin. Tobacco (Nicotiana glauca), a common ruderal species in the southwestern United States, contains the nicotine-like alkaloid anabasine. If you eat the green leaves of this plant, you may die from respiratory failure.

Mushrooms. Mushrooms with large fruiting bodies are found in a wide variety of habitats. Many of them are mildly poisonous, some are deadly. Under no circumstances should you eat unfamiliar mushrooms: there should not be the slightest doubt that the collected species are known to you and harmless. Only a few species pose a threat to life. Fortunately, poisoning with them can be treated based only on the symptoms, without trying to retroactively determine what type of mushroom caused them, which, for obvious reasons, is often simply unrealistic. If symptoms occur within the first 4 hours after consuming mushrooms, there is usually no threat to life. The clinical picture may include simple irritation of the gastrointestinal tract, for example in the case of Russula emetica, Lactarius torminosus, and Chlorophyllum molybdites; delirium (blurred consciousness) and dizziness after eating red fly agaric (Amanita muscaria) and panther fly agaric (Amanita pantherina); hallucinations in those who have eaten Psilocybe spp. The palatable edible dung beetle (Coprinus atramentarius) can cause nausea and vomiting for two days after consumption, but only if alcohol is consumed during this period. If symptoms of poisoning occur six or more hours after the mushrooms were eaten, the situation is considered much more serious. In North America, it was observed in two cases: with poisoning by stitches and toadstool. Intoxication with stitches (Gyromitra spp.) is less dangerous. Usually it is treated with a headache, but convulsions and coma are also possible. Pale grebe (Amanita phaloides) and its closest relatives, as a rule, cause continuous vomiting and diarrhea 12 hours after eating them. The polypeptide toxins of these fungi disrupt protein synthesis in the liver and can lead to liver failure and death after about a week, even under intensive treatment. See also MUSHROOMS.

Plants of steppes and semi-deserts. A number of poisonous species grow in the winter and summer grasslands of the western United States, and some of them occasionally kill sheep and cattle. As an example of the most dangerous plants in these places, we can name scrub oaks (Quercus spp.), Zigadenus spp., Sarcobatus vermiculatus, groundsworts (Senecio spp.), Hymenoxys odorata, Karwinskia humboldtiana), Nolina texana, Sophora secundiflora, Halogeton glomeratus, Delphinium spp., Astragalus spp., Asclepias spp. and Helenium autumnale ).

4. Types of poisonousplants and symptoms

There are two types of poisonous plants: those that are dangerous if touched, and those that are poisonous and unsuitable for food.

Poisonous plants that are dangerous if touched. Most of them belong to the families known botanically as sumac and spurge. The most important of these are poison ivy, poison oak and poison sumac. They all have compound leaves and small, round grey-green or white fruits. Knowing the signs of these plants and the effect they cause will help you in other parts of the world where similar plants bloom. A good remedy against their poison is wet wood ash, applied to the corresponding part of the body.

1) Symptoms from touching these poisonous plants are the same everywhere: redness, itching, swelling and blisters. The best remedy after contact with them, wash thoroughly using solid soap.

2) In the tropics and subtropics there is a wide variety of this type of plant.

The most common types are:

* black poisonous tree of Central America;

* carasco, a shrub in Western India;

* Rengas tree in Malaysia, the Philippines and the South Pacific Islands;

* varnished wood in China and Japan;

* some varieties of Asian “magnifera”;

* “blind eye”, white “mangrove” (mangrove tree), common in Australia, India and the islands of the South Pacific;

* milky juice of some plants, such as castor oil or castor beans, sap of the papaya tree.

Poisonous plants that are dangerous if consumed. The number of such plants is small compared to non-poisonous and edible ones. * Good rule is knowledge of edible plants, but if you have to eat unfamiliar ones, do it in small quantities and wait a while before continuing*.

1) In polar and subpolar regions you can be sure that only a dozen plants are poisonous. Two of the most poisonous in the far North are water hemlock and poisonous mushrooms.

2) If you have doubts about which plants are poisonous and which are not, watch birds, rodents, monkeys, bears and other herbivores. Usually the food they eat is suitable for humans. Follow these tips:

* do not eat plants that sting or pinch;

* boil the products of all plants that you have doubts about. The poison of many of them is neutralized in this way;

* do not consume plants with milky juice and do not allow it to come into contact with the skin. This does not apply to the many wild berries, breadfruit, papaya and barrel cactus;

* Avoid poisonous ergots with an infected head, found in cereals or grasses, they are distinguished by black seeds instead of the normal green ones.

Plants with stinging hairs. In general, they pose no real danger. Touching them is painful, which is explained by the effects of formic acid.

5. Geographical areaspread of poisonous plants

In equatorial countries there are more poisonous plants than in temperate countries, and the poisons contained in them are more powerful. If poisonous plants growing in the south, such as aconite and cherry laurel, are grown in the north, then their poisonous properties become weaker. But this does not mean that there are no poisonous plants in cold climates. Poisonous golden rhododendron grows in Siberia and Kamchatka; poisonous hellebores and buttercups are very widespread in cold climates.

Poisonous plants can be found in coniferous and deciduous forests, dry and wet, in swamps and marshy places, along river banks, in meadows and fields, and as weeds near dwellings. Let's look at the most dangerous and common plants.

In the forests of the European part of the USSR and the subalpine zone of the Caucasus you can find very beautiful shrubs wolf's bast. The height of the bush is from 30 to 120 cm. Wolf bast blooms in early spring, in April, before the leaves appear. Its fragrant pink flowers are located on the branch in dense bunches, the pedicels are very short. Wolf's bast has beautiful fruits - oval, bright red drupes. However, they are very poisonous and cause death to those who swallow them. The plant contains the glycoside daphnin. Poisoning with this poison causes convulsions and bloody diarrhea.

You can find shrubs next to the wolf's bast common honeysuckle, or wolf berries. The height of honeysuckle is from 1 to 2.5 m. Yellowish-white flowers, and then dark red berries, are arranged in twos on a common peduncle. By this feature, honeysuckle can be distinguished from other shrubs. The plant's fruits are poisonous.

European swimsuit. On the right are a flower and a root.

In the grass cover of conifers and mixed forests The European part of the USSR and the Caucasus is often found raven's eye four-leaf. This perennial low plant is easy to recognize - it is unlike any other. In the upper part of the stem (its height is 15-30 cm) there is a four-leaf whorl, from which emerges a peduncle with a greenish flower. The raven's eye berry is black with a bluish tinge. Poisoning from crow's eye rhizome causes vomiting; the berries affect the heart.

Poisonous plants: 1 - poisonous plant; 2 -- rhizome milestone in section; 3 -- poisonous sumac; 4 - sumac fruits; 5 -- wolf's bast with fruits; 6 -- wolf bast flowers; 7 -- raven eye; 8 -- fruit of the raven's eye; 9 -- hemlock; 10 - hemlock root; 11 - arum; 12 - arum fruits;

Almost throughout the country, a highly poisonous perennial is found in wet and damp forest meadows, swamps, and marshy banks of rivers and ponds. veh poisonous, or cicuta. The height of the pole reaches 120 cm. Its rhizome is thick, hollow inside, with partitions. Drops of yellowish-orange resin appear on the longitudinal section of the rhizome. The lower part of the hemlock stem is usually reddish, the double- and triple-pinnate leaves are thin and lacy. White flowers are collected in inflorescences - complex umbrellas. Umbrellas do not have a general wrapper, there are only private ones. Vekh blooms from June to September. The entire plant is poisonous, especially the rhizome. The poison acts on the brain; death occurs from respiratory paralysis. Veh is a very dangerous poisonous plant. Children most often die from it, since the rhizome of the vekha is sweet and children mistake it for celery. Vekh often grows near villages near streams, among whitewing and sedge. From the Umbrella family, to which Vekh belongs, they can also be found angelica And angelica But vekhs are easy to distinguish from them. The leaves of angelica and angelica, like those of vekha, are double- and triple-pinnate, but large. Angelica leaves have large, swollen vaginas.

A poisonous plant is found in shady forests and bushes in the southwest of the European part of the USSR and the Caucasus. spotted arum. Its leaves, rhizomes and berries are poisonous when raw. The toxic substance aronine alkaloid causes inflammation of the skin and mucous membranes.

A poisonous plant of the aroid family grows on the territory of the Soviet Union - swamp whitewing. It can be found on the banks of reservoirs and in swampy meadows. It got its name because after the fruits form, its white covering leaf opens like a wing. The raw rhizomes of the whitefly are poisonous, but they are edible when cooked.

13- chilibuha; 14 - chilibuha fruit; 15 - common spurge; 16 -- milkweed flower; 17 -- milkweed root; 18—great celandine; 19 -- celandine root; 20 - cockle; 21 -- cockle box and seed; 22 - cockle root.

It grows in peat bogs, in coniferous forests of the European part of the USSR, in Siberia and the Far East. wild rosemary -- shrub with a pungent, intoxicating odor. Blueberries, blueberries, lingonberries, and heather are often found together with wild rosemary. The height of wild rosemary is 50-120 cm. Its young branches, undersides of leaves, pedicels and capsule fruits are densely covered with rusty-brown felt. Ledum blooms in May - June with white bell-shaped flowers. The entire plant is poisonous, especially the leaves.

Grows in beech forests and on the mountain slopes of the Crimea, Caucasus and Carpathians belladonna(belladonna) is one of the most poisonous plants. All parts of the plant are poisonous, often three of its berries are a lethal dose. Death occurs from respiratory arrest.

There are many other poisonous plants in deciduous and mixed forests: European hoofweed, spiky crowberry, oak anemone, buttercup And forest, perennial scilla, lily of the valley, dream grass. They grow on marshy river banks, in swampy meadows and generally in damp places. European swimsuit (roots are poisonous) Water meadowsweet, white hellebore, acrid buttercup.

An evergreen, highly poisonous coniferous tree grows in the beech forests of Crimea and the mountain forests of the Caucasus. yew, living up to 3-4 thousand years. Most often, yew grows in the form of a densely branched shrub; its wood is reddish, very hard and dense. The leaves (needles) of yew are linear, flat, shiny. The fruits are red. Needles, bark and wood are poisonous, especially old needles. The poison affects the heart; death from poisoning can occur from suffocation.

In Transcaucasia and on the Black Sea coast it grows wild and is cultivated evergreen tree up to 10 m high -- boxwood It is also grown in gardens and parks as a border shrub. Boxwood bark is grayish, leaves are oval, shiny, leathery. The flowers are small, collected in balls, the fruit is a capsule. The plant has an unpleasant odor. All parts of boxwood are poisonous. Death in case of poisoning occurs from suffocation.

There are many poisonous plants among the weeds. They are all the more dangerous because they grow near houses - in vacant lots and vegetable gardens. Most common hemlock, widespread in the European part of the USSR, the Caucasus, Central Asia and Western Siberia. The hemlock stem is covered with a bluish coating and red-brown spots. The flowers are small, white, collected in complex umbels. Blooms from June to autumn. One of the signs is smell: hemlock smells like mice. All parts of the plant are poisonous, especially the fruits. After poisoning, death occurs from suffocation.

6. Likeescape biohazard

It is very important to be able to distinguish poisonous plants and of course, know what to do if poisoning does occur. First of all, you should know your native nature well, then you can easily identify dangerous plants. You should not eat unknown plants, as well as those whose appearance raises the slightest doubt.

6.2 Methods of prevention when exposed to biological hazards.

You can only collect or eat plants that you know well. You need to be more careful and careful. Do not take unknown plants or berries. If trouble happens, you need to act quickly and decisively. Try to induce vomiting or have water with you, drink a lot and try to flush your stomach in this way. Vomiting can be induced artificially by pressing the handle of a spoon or two fingers on the root of the tongue. This is a simple method of cleansing the stomach. It must be repeated several times until water appears. And of course, you need emergency medical care as quickly as possible. Even if after cleansing the stomach it becomes easier, you still need to consult a doctor to avoid death.

7. Conclusion

The purpose of this work was to consider those poisonous medicinal plants that, in addition to their benefits, can be dangerous. These plants contain highly toxic substances. Everyone should distinguish poisonous herbs from others. Distinguish and teach this to your children.

8. Sources

1. Small medical encyclopedia. - M.: Medical Encyclopedia. 1991--96

2. Acute plant poisoning. -- Kyiv // Health, 1981.

3. Poisonous and harmful plants of meadows, hayfields, pastures. Characteristics, destruction measures. M.: Rosselkhozizdat, 1971.

4. Plant life/Ed. A. A. Fedorova. M.: Education, 1972-1974.

5. Anatomical. Atlas of useful and some poisonous plants. L.: Nauka, 1982.

6. Internet resources:

www.taiga-travel.ru

www.dic.academic.ru

www.znahar-celitel.ru

www.3planet.ru

Posted on Allbest.ru

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In the desert, stunted and stingy

On the ground, hot in the heat,

Anchar, like a formidable sentry,

Standing - alone in the whole universe.

Nature of thirsty steppes

She gave birth to him on the day of wrath

And green dead branches

And she gave the roots poison.

Poison drips through its bark,

By noon, melt away from the heat,

And it freezes in the evening

Thick transparent resin...

A. S. Pushkin

Surrounding a person The world is divided into living and nonliving. A distinctive feature of living objects is their ability to grow and reproduce.

Biological(bio from the Greek bios - life) are called dangers arising from living objects.

All objects of the living world can be divided into several kingdoms; namely: microorganisms (Protista), fungi (Fungi, Mycetes), plants (Plantae), animals (Animalia), people (Homo sapiens).

The science that studies the patterns inherent in life in all its manifestations and properties is called biology.

The living world is very diverse. But there is one very important common property that all living beings have - their cellular structure. Cells are the building blocks that make up all living beings, their tissues, organs and organisms as a whole.

Cell- This is the smallest form of organized living matter, capable of existing independently in a suitable environment and conditions. The cellular structure of living objects was discovered by the Englishman Robert Hooke in 1665. Plants, animals, and people are multicellular, and microorganisms, as a rule, are unicellular creatures.

There is a constant struggle between various living beings. In this struggle, a person does not always emerge victorious.

Carriers, or substrates, of biological hazards are all habitats (air, water, soil), vegetation and animal world, people themselves, the artificial world created by man, and other objects.

Biological hazards can have different effects on humans - mechanical, chemical, biological, etc.

Biological hazards result in various diseases and injuries of varying severity, including fatal ones.

Based on the principle of expediency that prevails in nature, it can be argued that all living beings perform a certain role intended for them. But in relation to humans, some of them are dangers.

Knowledge of biological hazards is one of the conditions for successfully protecting a person from hazards in general and biological hazards in particular.

In each kingdom of living beings there are several types, subdivided into squads, in squads - several classes; in every class – some orders; the latter are divided into families, consisting of rows, and the rows are divided into kinds.

Each living object has its own name, which consists of two words. The first word, written with a capital letter, denotes the name of the genus of a given organism, and the second is its specific epithet. This binary nomenclature was introduced by the Swedish scientist Carl Linnaeus. For example, the tuberculosis bacillus has the scientific name Mycobacterium tuberculosis, yeast - Saccharomyces cerevisiae, tetanus bacillus - Clostridium tetani.

Some microbes resemble animals in their properties, others resemble plants. To understand the essence and nature of biological hazards, let us consider in more detail each kingdom of living beings.

MICROORGANISMS

Microorganisms- these are tiny, mostly single-celled creatures, visible only through a microscope, characterized by a huge variety of species that can exist in different conditions.

Microorganisms play a useful role in the cycle of substances in nature; they are used in the food and microbiological industries, in the production of beer, wine, and medicines.

Some types of microorganisms are pathogenic or pathogenic. They cause diseases in plants, animals and humans.

Diseases such as leprosy, plague, typhus, cholera, malaria, tuberculosis and many others, in ancient times, claimed thousands of lives, sowing superstition and fear among the population. For a long time, humanity did not know that these diseases are caused by microorganisms. There were no means to combat infectious diseases. Therefore, human infectious diseases sometimes become widespread, which is called an epidemic or pandemic.

The widespread spread of contagious animal diseases is called epizootic, and plants - epiphytoty.

Humanity has persistently sought the answer to terrible diseases.

The ancient Greek scientist Democritus (460-370 BC) expressed the opinion that diseases are caused by tiny organisms that penetrate the body of humans and animals. It was a brilliant foresight, which was confirmed only more than 2000 years later.

The “father” of medicine, Hippocrates (460-377 BC), made a significant contribution to the doctrine of the origin of diseases, creating the theory of “pathogenic miasms”.

Aristotle (384-322 BC) rightly argued that rabies is transmitted through the bite of rabid dogs.

The Hippocratic theory of “miasma” was also supported by the most prominent Roman physician, Claudius Galen (130-200 BC).

The famous Swiss physician Paracelsus (1493-1541) believed that the causative agents of infectious diseases are living beings. In his writings, he often uses the word “virus”.

The outstanding Italian physician G. Fracastoro (1478–1553) also suggested that the causative agents of diseases are special organisms that multiply very quickly. Fracastoro described a number of animal diseases: foot and mouth disease, glanders, sheep pox, etc.

In 1348-1350 In the Old World, 7,500,000 people died from the plague epidemic, i.e. almost half of the population living in Europe at that time. During the plague epidemic (1364), so few people were alive in Moscow that they could not bury the dead. Throughout the Middle Ages, smallpox, bacillary dysentery, typhus, leprosy and influenza caused great damage to the population. Epizootic diseases were also devastating, during which millions of animals died. In many European cities, monuments have been erected to those who died during epidemics.

The era of great disasters is vividly reflected in literary works. For example, G. Boccaccio in his “Decameron” described an epidemic in Florence. The great utopians T. More and T. Campanella paid a lot of attention in their works to the problems of protection against infectious diseases.

From ancient times to the 17th century. Scientists from different countries and peoples have expressed many ideas about the causes of infectious diseases and ways to combat them. Among them were brilliant guesses, which have already been mentioned, as well as superstition and scholasticism.

In the 17th century, two anti-scholastic trends appeared in science: empiricism and rationalism.

The luminary of the first was F. Bacon (1561-1626), the second - R. Descartes (1596-1650). Representatives of these movements were determined to break the scholastic canons and to find the truth through research and experimentation at all costs. Science was placed on a solid foundation of materialism. At this time the foundations of modern science were laid. It was during this period that the era of great discoveries in biology began, related to the problem of biological hazards under consideration.

DISCOVERY OF LEVENHOEK

As we already know, many ancient scientists expressed the idea of ​​the existence of small living creatures that penetrate the body and cause diseases. But no one saw these creatures.

The Dutchman A. van Leeuwenhoek was the first to see bacteria. This happened in 1676. It is known that the first microscope was built in 1590 by 3. Jansen (Netherlands).

R. Hooke brilliantly used the microscope in his research, discovering the cellular structure of tissues. Leeuwenhoek (1632-1723) discovered bacteria by accident while working on another problem. He was very interested in the living creatures he saw, which he called “little animals.” Leeuwenhoek devoted more than 50 years of his life to the study of microorganisms, studying the shape and size of bacteria (Fig. 24).

Sketches of bacteria by Leeuwenhoek

microbiology

Leeuwenhoek's accidental discovery became the beginning of a new science - microbiology. Its founder is recognized as the outstanding French scientist L. Pasteur (1822-1895). Pasteur was a chemist by education. Having become interested in biology, he established that every infectious disease arises as a result of the pathogenic activity of a special type of microbe and proposed ways to combat them.

Pasteur's genius lies in the fact that he used the principle weakening the pathogen. A weakened pathogen, without causing disease, creates immunity in the body of a person or animal that has been vaccinated.

The equally famous doctor R. Koch was involved in the search for pathogens of infectious diseases. He discovered the causative agents of anthrax, tuberculosis and cholera.

Microbiology studies microorganisms, their systematics, morphology, genetics, role in the cycle of substances in nature, pathogenic effects leading to diseases of humans, animals and plants.

Microorganisms are very diverse. They are sometimes simply called microbes (from the Greek mikros - small and bios - life).

As the name suggests, microorganisms are very small objects. Therefore, microbiologists use small units of measurement, such as micrometer, nanometer, and even angstrom.

Most bacteria have a size of 0.5-1 microns, yeast fungi – 5-10 microns.

The smallest bacteria have a diameter of about a tenth of a micrometer.

Some types of bacteria and fungi reach a length of several millimeters and even centimeters. But, as a rule, microorganisms are very small living creatures that a person cannot see without the help of a microscope.

Mycoplasmas- This is a type of microorganisms that live in water bodies and manure. Pathogenic mycoplasmas cause diseases in humans (pneumonia), animals (pneumonia), and plants.

bacilli(from Latin bacillum - rod) are rod-shaped bacteria that form intracellular spores.

Aerobes- organisms that can live only in the presence of atmospheric oxygen.

Anaerobes- organisms that can live in the absence of atmospheric oxygen.

Bacteriology– a branch of microbiology that studies bacteria.

WHAT ARE THERE ARE MICROORGANISMS

Among pathogenic microorganisms there are bacteria, viruses, rickettsia, spirochetes, protozoa.

Protozoa consist of one cell. Most often they live in bodies of water. Examples of protozoa: amoeba, radiolaria, gregarina, euglena, trypanosoma, myxosporidium, paramecium.

The carriers are blood-sucking insects (tsetse flies). The disease is caused by trypanosomiasis, which affects people and animals (fever, damage to the lymph nodes, etc.). The disease in humans is called sleeping sickness (African trypanosomiasis) or Chagas disease (American trypanosomiasis).

Euglena found mainly in small fresh water bodies, often causing water blooms, about 60 species are known, length up to 0.1 mm.

Despite their name, protozoa are even more complex than a single cell. K. Linnaeus also “neglected” the protozoa, describing them as one genus, called “chaos infusorium.”

The usual sizes of protozoa are 1/20-1/7 mm. They can be seen without a microscope (the human eye can distinguish objects up to 0.1 mm in size).

They reproduce by division every 3 hours.

Bacteria – typical representatives of microorganisms. Bacteria shaped like regular balls are called cocci. Groups of cocci are called staphylococci or streptococci. Cocci include causative agents of various infectious diseases. Many bacteria have the form of rods, for example, Escherichia coli (Eschericha coli), the causative agent of typhus (Salmonella typhi) and dysentery (Shigella dysenteriae), that lives in our body.

An electron microscope also allows you to see the organs of movement of bacteria - thin flagella.

Bacteria are ubiquitous and resilient. They were found in the water of geysers with a temperature of about 100°C, in the permafrost of the Arctic, where they remained for more than 2 million years; They don’t die in outer space, and exposure to a dose of radiation lethal to humans is not scary for them either.

Among them there are bacteria - predators that catch protozoa. Some bacteria feed on ammonia and methane. They tried to use them to “eat” methane in mines. Bacteria reproduce by simple division in two, in favorable conditions, every 20 minutes.

Bacterial diseases are plague, tuberculosis, cholera, tetanus, leprosy, dysentery, meningitis, etc.

The plague killed tens of millions of people in the Middle Ages. This disease terrified people. It is believed that in the 20th century. the danger of plague had disappeared.

Tuberculosis bacteria were discovered by R. Koch in 1882, but this disease has not been completely defeated.

Cholera was brought to Europe in 1816; before 1917, more than 5 million people in Russia suffered from cholera, half of them died.

V. Mayakovsky wrote the following lines:

Citizen! To avoid dying from cholera,

Take these measures in advance.

Don't drink raw water. This water

Drink only boiled water.

Also, don’t drink kvass on the street.

Boiling water is a lot of work.

So that you can keep up with your kvass early,

They just cook it from the tap...

Nowadays, cases of cholera are rare.

Tetanus affects the nervous system. The disease is defeated with the help of preventive vaccinations.

Cases of leprosy became rare. Sick people are still placed in leper colonies.

So, viruses have the following features compared to bacteria. Viruses have this characteristic: filterability, that is, they pass through filters. Pasteur's student Charles Chamberlant used a special porcelain filter (Chamberland's candle) to filter liquids in which bacteria multiplied, which retained the smallest of all known bacteria. It was this filter that was used to prove the non-bacterial nature of the rabies pathogen.

Viruses, unlike bacteria, are not able to exist and reproduce on their own. Each bacterium is a cell with its own metabolism. Bacteria are able to grow and multiply on artificial nutrient media.

Bacteria and living cells of the body always simultaneously contain two types of nucleic acids: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Viruses contain only one type of nucleic acid—either RNA or DNA.

Viruses are capable “impose” your genetic information the hereditary apparatus of the cell affected by it.

Viruses infect a cell and force it to help them reproduce, which usually ends in the death of the cell. Viruses, unlike bacteria, reproduce only in living cells. Therefore, viruses are studied at the level of an experimental animal or cell culture.

Viral diseases are smallpox, rabies, influenza, encephalitis, measles, mumps, rubella, hepatitis, etc.

Ancient manuscripts brought to us descriptions of terrible smallpox epidemics, in which up to 40% of patients died. The Englishman E. Jenner proposed his own method of smallpox inoculation (vaccination) in 1796, thereby marking the beginning of the fight against this disease. But it was not until 1980 that the WHO declared that smallpox had been eradicated. Children born after 1980 are no longer given smallpox vaccinations.

Rabies, or hydrophobia, is a fatal disease of humans and animals, known since ancient times. Rabies most often occurs in dogs. Wolves, cats, rats, crows and other animals also suffer from rabies.

Vaccinations – the only reliable remedy against rabies. The first rabies vaccination was given L. Pasteur in 1885. A child severely bitten by a rabid dog did not get sick. It is impossible to cure a sick person from rabies. The latent (incubation) period of the disease lasts from 8 days to a year. Therefore, in case of any animal bite, you should consult a doctor.

In 1981, in San Francisco (USA), people were discovered suffering from unusual forms of pneumonia and tumors. The disease ended in death. As it turned out, these patients had a sharply weakened immune system (protective properties) of the body. These people began to die from microbes that under normal conditions cause only mild illness. The disease was called AIDS - acquired immunodeficiency syndrome.

AIDS viruses were simultaneously discovered in 1983 by biologists in France and the USA. It has been established that the AIDS virus is transmitted through blood transfusion with non-sterile syringes, sexual intercourse, and also when feeding a child with breast milk.

For the first six months to a year, and sometimes for several years after infection, a person does not show any signs of illness, but he is the source of the virus and can infect others. Until now, no cure for AIDS has been found. AIDS is called the “plague of the 20th century.”

The influenza epidemic was described by Hippocrates back in 412 BC. e.

In the 20th century There have been 3 influenza pandemics. In January 1918, reports of an influenza epidemic called the “Spanish flu” appeared in Spain. The Spanish Flu traveled around the world, infecting about 1.5 billion people, passing only a few islands lost in the ocean and claiming 20 million lives - more than the First World War.

In 1957, about 1 billion people fell ill with the “Asian flu”, and more than 1 million people died. In 1968-1969, the “Hong Kong flu” raged on planet Earth.

The number of influenza epidemics, oddly enough, increases every century. In the 15th century there were 4 epidemics, in the 17th century. – 7, in the 19th century. – already 45!

Why are there still no reliable flu shots? It turns out that the influenza virus changes very quickly. No sooner have doctors made a vaccine against one form of influenza than the pathogen appears in a new form.

Rickettsia(on behalf of the American scientist Ricketts) - small pathogenic bacteria that multiply in host cells (just like viruses). They cause rickettsioses (typhus, Q fever, etc.) in humans and animals.

Rickettsial disease, same as Q fever. Q fever (rickettsiosis Q) is an acute infectious disease of humans and animals caused by rickettsia. Signs of the disease: headache, weakness, insomnia, muscle pain. In animals it is asymptomatic. Humans become infected from animals.

Spirochetes – microorganisms whose cells have the shape of thin twisted threads. They live in soil, standing and Wastewater Oh. Pathogenic spirochetes are the causative agents of syphilis, relapsing fever, leptospirosis and other diseases. Spirochetoses are diseases of humans and animals caused by pathogenic spirochetes.

Actinomycetes, microorganisms with organizational features of bacteria and protozoan fungi. Distributed in soil, water bodies, and air. Some species are pathogenic and cause diseases such as actinomycosis, tuberculosis, diphtheria, etc. Some actinomycetes produce antibiotics, vitamins, pigments, etc. They are used in the microbiological industry.

GROWTH AND REPRODUCTION OF MICROORGANISMS

Like all living things, single-celled microorganisms grow. Having reached a certain size, the cell stops growing. Under a microscope you can observe how at a certain moment it divides into two parts, which become independent organisms. So from one mother cell two daughter cells appear. As they grow, they also divide, forming four cells, then eight, sixteen, etc. in geometric progression.

The first scientist to see under a microscope how a microbe divides in half was L. Spalanzani (1729-1799). This was in 1776. The time from the emergence of a cell to its division is called generation time. There is a certain pattern in nature: the smaller the organism, the sooner it produces offspring. Thus, the generation time of Escherichia coli and the cholera causative agent Vibrio cholerae is only 20 minutes. Using the geometric progression formulas:

Where A 1 and and n – respectively, the first and any terms of the progression, q – progression denominator; P - taken member number; S n – the sum of the first n-members, you can count the number of bacteria formed over a certain time. Calculations show that within 24 hours it is impossible to form from one bacterium. a large number of cells. Consequently, the process of microbial reproduction is limited to certain conditions. The French scientist J. Monod studied the growth of bacteria and established the following pattern. At first, bacteria adapt to the environment and multiply very slowly. This period is called lag phase. This is followed by a phase of rapid reproduction according to the logarithmic law (log phase), after which a stationary phase begins, when the environment is enriched with bacterial waste products that inhibit the reproduction process and, finally, the bacteria begin to die off (die-off phase) (see Fig. 25).

The cause of bacterial death is unfavorable environmental conditions:

1) Usually microorganisms live normally at a temperature of 0-90°C. For some species this limit is much wider: from -270 to +400°C.

2) Direct rays of the sun are harmful to most bacteria.

3) Microorganisms are viable under very low pressure(only 5 mm Hg) and very high (more than 5 atm.).

4) The viability of microorganisms is affected by the pH reaction of the environment. The most favorable environment is neutral (pH = 7) or alkaline (pH > 7).

Substrates (carriers) of biological hazards can be elements of the environment (air, water, soil), plants, animals, people, equipment, tools, raw materials, recyclable materials, etc.

Bacteria live in water, including hot springs, in ice, and in the air at various heights from the ground. There are especially many bacteria in soils. One gram of arable soil contains from 1 to 20 billion microbes. Microbes accompany a person throughout his life. Life is impossible without microbes. But pathogenic microbes are dangerous for humans. Therefore, people persistently look for ways to protect themselves from pathogenic microbes. Spallanzani also proved that when liquids are boiled for a long time, the microbes in them die. The German scientist Schwann found that high temperatures also kill microbes in the air. Physicist Tyndall proved that microbes in liquids die after repeated boiling. Repeated short-term heating of a liquid to the boiling point, proposed by Tyndall, is called tyndalization. All methods of destroying microbes under the influence of high temperature have a common name - sterilization. Partial sterilization of milk by heating to 60°C for 30 minutes is called pasteurization.

To capture microbes from liquids and gases, special filters are used that have very small pores.

Pathogenic microbes secrete enzymes that disrupt the normal state of a person.

Bactericides – chemicals that kill bacteria.

Bacteriositase – temporarily stopping the proliferation of bacteria under the influence of various substances (including drugs).

Bacteria traps – devices for taking air samples to determine the degree and nature of bacterial contamination.

Bacterial carriage And virus carriage – the presence of pathogens of infectious diseases in the body of a person or animal in the absence of signs of disease.

BACTERIOLOGICAL RATING

The principle of standardization of bacteriological pollution can be implemented in practice on the basis of direct and indirect indicators.

Direct methods consist in establishing the relationship between the fact of the disease and the discovery of the corresponding pathogenic microbes. However, due to the long incubation period and the relatively low incidence of diseases, direct methods are considered not reliable enough.

In this regard, they began to use indirect indicators bacterial standardization of water quality. One of the first indirect indicators of bacterial contamination of water that is dangerous to health was proposed to be the total number of bacteria grown on a nutrient medium of 1 ml of undiluted water. When deciding what amount of bacteria settled in water can be considered safe, R. Koch’s recommendation was chosen, which he made based on a study of the cholera epidemic in Hamburg in 1892. Comparing the quality drinking water, which was supplied to the population of Hamburg, with the quality of water in the neighboring city of Altona, which remained free from the cholera epidemic, R. Koch noted that the purification of water on filters in the city of Altona until it contained no more than 100 microbes per 1 ml ensured the safety of the population during cholera epidemics.

In 1914 in the first drinking water quality standard in In the USA, a value of no more than 100 bacteria per 1 ml was used as a standard for acceptable total bacterial contamination. The second time in world practice this was done in the USSR in 1937. Subsequently, this indicator was adopted in the standards of almost all European countries.

The second indirect indicator is the number of E. coli. Research by scientists has proven that E. coli can serve as a sanitary indicator microorganism.

In 1937, a temporary standard for the quality of water supplied to the water supply network was adopted, according to which the number of E. coli in 1 liter of water should be no more than 3, or the coli titer should be no less than 300. This standard has been tested by many years of practice in centralized water supply in the USSR. Compliance with this standard creates the necessary degree of safety against infections that may spread by water. It has been proven that when the number of E. coli approaches 3 in 1 liter, the absence of viable and virulent (pathogenic) microorganisms in the water is achieved.

The human body contains a wide variety of microorganisms. Some are harmless, others are even useful. Pathogenic microbes are distinguished by the fact that they secrete enzymes that decompose blood cells, muscles, and mucous membranes, thereby disrupting the normal state of the body. A special group is formed by pathogenic microbes that secrete potent poisons(toxins) that poison the affected body. Aggressins contained in bacteria also have a destructive effect on the human body.

Microbes enter the human body mainly in three ways: through the respiratory organs, digestive tract and skin.

Infection through the respiratory tract is called droplet infection.

Animals and insects are carriers of pathogenic microbes.

Food can be a breeding ground for microbes that produce toxins. Clostridium botulinum grows in meat foods and produces botulinum toxin, a very powerful poison. Pathogenic microbes remain viable in water for a very long time. But a person cannot go without water for a long time. Hence the constant threat of infection. A severe cholera epidemic broke out in St. Petersburg in 1908-1909. The reason is the ingress of wastewater from the canal into the water supply network.

A person has good natural protection against pathogenic microbes. The first line of defense is our skin. But the slightest wound opens access for microbes to the body. In the nasal cavity, microorganisms are retained by small hairs. In the oral cavity, bacteria are retained by saliva, which contains a bactericidal substance known as lysozyme Lysozyme is found in tears. This was established by A. Fleming. In 1965, biochemists determined the composition of lysozyme, the molecule of which contains 129 different amino acid residues. Lysozyme dissolves the cell walls of a number of bacteria and destroys bacteria. But if microbes still manage to penetrate the body, then they are faced with the acidic environment of the stomach, which destroys most of the microorganisms. Some microbes still penetrate the intestines. Here another obstacle awaits them. I. I. Mechnikov showed in 1883 that white blood cells (leukocytes) are capable of actively capturing and absorbing foreign microbes that have entered the body. Mechnikov called this phenomenon phagocytosis, and white blood cells - phagocytes. Based on these facts, it was developed phagocytic theory of immunity.

Immunity can be acquired or natural or innate.

In 1796, the English doctor E. Jenner discovered a method of preventive vaccinations, which he called vaccination, and the material for vaccinations vaccine (from the Latin vacca - cow).

Immunity to infections created artificially is called immunization. Immunization with serum is passive, while immunization with vaccine is active.

Hygiene is of great importance in the fight against germs. Sweat, dust, dirt are a good breeding ground for microorganisms.

An effective remedy anti-microbial disinfection. The following disinfectants are used: tincture of iodine, ultraviolet rays, chlorine, etc. Disinfection is a direct means of combating microbes.

Disinsection and deratization are aimed against microbial carriers.

Pest control – insect control agent. The drugs used for disinfestation are called insecticides. A lot of them. All of them have chlorine as a component.

Rodent control is called deratization. In this case, chemical, mechanical and biological means are used.

GOST 12.1.008-76 “Biological safety” obliges to take appropriate measures when working with biological objects in order to prevent workers from developing diseases, carrier states, intoxication, sensitization and injuries caused by microorganisms.

MUSHROOMS

Mushrooms - a separate group of lower plants lacking chlorophyll and feeding on ready-made organic substances. Mushrooms are classified into a special kingdom of the organic world. There are over 100 thousand species of mushrooms. Fungi are distinguished from bacteria by the presence of a nucleus in the cell.

Pathogenic fungi cause diseases in plants, animals and humans.

Mushroom Science – mycology.

Mushrooms have 3 forms of reproduction: vegetative, asexual and sexual.

Let's look at some mushrooms. The most poisonous mushroom in the world - death cap. The poison of the toadstool is not destroyed by boiling, frying, or processing in any other way. This mushroom poses a mortal danger to humans. A person can get poisoned red fly agaric, but deaths are rare. Almost every edible mushroom has its inedible or poisonous counterpart. This poses a danger to an inexperienced mushroom picker.

PLANTS

Even in ancient times, people noticed that some plants have both medicinal and poisonous properties. As Paracelsus argued, only one dose makes a substance a poison or a medicine.

Chilibikha. The natives of South America lubricated their arrows with curare poison. It was obtained from plants of the loganiaceae family containing strychnine. Once in the blood, strychnine causes spinal cord paralysis and death. The most famous representative of this family is chilibiha (vomit nut), growing in the tropics. This is a small tree no more than 15m high. But curare is also used for medicinal purposes, for example for snake bites. Injecting curare into the body as a medicine is called curarization.

Anchar. Poisonous anchar grows in South Asia. Its milky sap is poisonous, but not fatal.

Plants such as foxgloves, oleander, coca leaf are poisonous, and at the same time medicines are obtained from them.

Henbane. The fruits of black henbane are dangerous. They contain alkaloids that cause mental confusion. Hence the expression “henbane has eaten too much.”

Tobacco. Appearance in the 15th century. tobacco in Europe is associated with the name of the Frenchman Jean Nicot, who allegedly brought the seeds of this plant from the island of Tobago. This is where the Latin name for tobacco comes from – Nikotiana tabacum. Tobacco contains the poisonous alkaloid nicotine. Lethal dose Nicotine is contained in about 20 cigarettes, but since it enters the body gradually, the smoker does not die. Nicotine spreads very quickly throughout the smoker’s body. It enters the brain 5-7 seconds after the first puff. The tar produced when tobacco is burned can cause tumors. Lung cancer is several times more common among smokers than among non-smokers. One of English kings described smoking as “a custom disgusting to the eyes, hateful to the nose, harmful to the chest, dangerous to the lungs.” Goethe noted: “An educated person does not smoke.” There was a time when in Russia people were punished for smoking with whips. There was a custom of sniffing and chewing tobacco. Many crops were brought from America to Europe - potatoes, tomatoes, sunflowers, etc. Tobacco is the most unnecessary of them. True, tobacco dust is used beneficially in agriculture to combat harmful insects.

Hemp. Dangerous drugs known as hashish, marijuana, and anasha are obtained from the resinous secretions of hemp, the use of which leads to the development of a serious disease - drug addiction.

Nettle. In spring, green cabbage soup made from young nettles helps replenish the lack of vitamins in the body that has formed over the winter. Nettle leaves are covered with hairs containing pungent juice. The hairs are impregnated with silica and are very fragile. At the slightest touch, the hair heads break off, the caustic juice enters the wounds, causing burns and skin irritation.

Biological hazards are called dangers emanating from living objects. The concept of “biological hazard” means “an infectious agent (or part of it) that poses a potential danger to a healthy person, animal and/or plant through direct exposure (infection) or indirect influence (through environmental destruction).”

Biological hazards may be associated with:

1) with plants (tobacco contains the poisonous alkaloid nicotine; henbane contains alkaloids that cause clouding of the mind; opium is obtained from poppy seeds; dangerous drugs are obtained from hemp - hashish, marijuana, anasha; unripe elderberries cause diarrhea, nausea and vomiting; etc. .d.);

2) with animals (the poison of the karakurt spider disrupts the functioning of the heart and makes it difficult to breathe; on September 19, 1981, when people found themselves in the water as a result of the accident of a passenger ship in the Brazilian port of Obidus, piranhas ate more than 300 people; 35 people die from sharks every year; poison viper is fatal to humans; etc.);

4) with microorganisms(bacteria and viruses) that cause various diseases in humans, animals and plants.

The cause of a biological emergency can be a natural disaster, a major accident or catastrophe, the destruction of a facility associated with the research of microorganisms, as well as the introduction of pathogens into the country from neighboring territories (terrorist act, military action).

Biological contamination zone- this is the territory within which biological agents that are dangerous to people and animals are distributed (introduced)

and plants.

Site of biological damage(OBP) is an area within which there has been a massive destruction of people, animals or plants. OBP can form both in the zone of biological contamination and beyond its borders as a result of the spread of infectious diseases.

On the same territory, foci of chemical, bacteriological and other types of pollution may simultaneously arise. Sometimes the outbreaks completely or partially overlap each other, aggravating the already difficult situation. In these cases there are foci of combined lesions(OKP), within which there are large population losses, it is difficult to provide assistance to victims and conduct emergency rescue and other urgent work(ASDNR).

from animal to animal and from animal to human. They are most often transmitted through blood-sucking insects and ticks.

Plague, tularemia, tick- and mosquito-borne encephalitis, tick-borne typhus are examples of natural focal diseases. People and domestic animals can become infected with natural focal diseases by entering areas where there are habitats of vectors and pathogens. Particularly dangerous infectious (contagious) diseases are plague, cholera, and smallpox, which are transmitted through contact with sick people.

Infections enter the body through the skin, wound surfaces, mucous membranes, including the respiratory system, digestive tract, etc. Depending on the place of infection, all infectious diseases are divided into four groups:

1) intestinal infections;

2) respiratory tract infections (aerosol);

3) blood (transmissible);

4) infections of the outer integument (contact).

The causative agents of infectious diseases in humans and animals can be pathogenic bacteria, viruses, rickettsia, fungi, plants and toxins, the carriers of which can be insects, animals, humans, habitats and bacteriological weapons.

The use of biological agents in war time to defeat military formations, civilians and economic facilities is possible not only in the area of ​​military operations, but also deep in the territories of the warring parties.

Features of the action of bacteriological agents (bacteriological agents):

the ability to cause widespread infectious diseases when released into the environment in negligible quantities;

the ability to cause severe illness (often fatal) when ingested in a negligible amount;

many infections are quickly transmitted from a sick person to a healthy person;

retain their damaging properties for a long time (some forms of microbes - up to several years);

have a latent (incubation) period - the time from the moment of infection to the appearance of the first signs of the disease;

contaminated air penetrates into unsealed rooms and shelters and affects unprotected people and animals in them;

the complexity and duration of laboratory research to determine the type and nature of the causative agent of the disease.

Signs of the appearance of funds:

an unusual for a given area and a given time of year accumulation of insects or rodents - the most dangerous carriers of pathogens;

mass diseases among people and animals;

mass death of livestock.

Biological agents, like chemicals, do not have a direct impact on buildings, structures and equipment, but their use may affect production activities enterprises, since a temporary shutdown of production is required.

Dangerous and especially dangerous human diseases

An epidemic is a widespread spread of an infectious disease, significantly exceeding the incidence rate usually recorded in a given territory.

A pandemic occurs when a human infectious disease spreads across a number of countries or an entire continent.

Epidemic process is the phenomenon of the emergence and spread of infectious diseases among people, representing a continuous chain of sequentially occurring homogeneous diseases.

The conditions for the emergence and maintenance of the epidemic process are considered to be the presence of sources and routes of transmission of infection, human susceptibility to infection and a number of social factors.

Sources of infection are infected people or animals. From them, microorganisms can be transmitted to healthy people.

Main routes of transmission: airborne, foodborne, waterborne, transmissible (through blood) and contact.

Human susceptibility to infection - This biological property body tissues to be an optimal environment for the propagation of the pathogen and respond to its introduction by the infectious process.

Social factors. Since the infectious process occurs in human society, social factors are important: living conditions, level of sanitary culture, medical care of the population, population density, material condition, public amenities, nature of food, water supply, etc.

Infectious diseases occur more often if:

the level of sanitary culture is low;

people live crowded;

sanitary and technological rules for preparing and storing food are violated (unwashed vegetables and fruits are consumed, water is taken from random sources);

personal hygiene rules are not observed (washing hands before eating and after visiting the toilet, etc.).

The causative agents of dangerous and especially dangerous infections are characterized by:

high pathogenicity (the ability to cause diseases);

high resistance to environmental influences;

the ability to maintain long-term viability and virulence (pathogenic properties) in water, food, and on objects;

the ability to be transmitted from person to person in various ways;

the ability to cause severe clinical forms of the disease, often accompanied by complications and leading to death.

Decree of the Government of the Russian Federation of December 1, 2004 No. 715 approved a list of diseases that pose a danger to others: plague, cholera, tuberculosis, anthrax, malaria, hepatitis B, C, diphtheria, infections predominantly sexually transmitted, viral fevers, disease, caused by the human immunodeficiency virus (HIV).

Chapter 3. Biological hazards and protection against them

Characteristics of some dangerous and especially dangerous human infectious diseases

Plague is an acute infectious disease of humans and some animals caused by the plague bacillus.

This disease terrified people; it was called the “Black Death.” Humanity knows three plague pandemics (VI, XIV, XIX centuries). Developing shipping contributed to the passive migration of rats and the introduction of plague with them to various countries. For example, in 1347, an epidemic of bubonic plague began in Europe, which was brought from ships that came from overseas countries. When, three years later, the epidemic ended, it turned out that it had claimed a quarter of the European population - 25 million lives.

Clinically, the plague is characterized by general severe intoxication, severe damage to the cardiovascular system and local manifestations, which depend on the location of the pathogen.

Forms of plague: pneumonic (lung damage); bubonic (damage to lymph nodes); cutaneous bubonic (carbuncles and skin ulcers with damage to the lymph nodes).

A carbuncle is an acute purulent inflammation of the skin and subcutaneous tissue, emanating from the hair follicles and sebaceous glands. A bubo is a painfully enlarged lymph node (Fig. 3.1).

All forms of the disease without special treatment quickly lead to death. Probability of death is 90%.

In Russia, carriers of the plague infection are gophers, rats and other rodents.

The presence of natural foci of plague in Russia (Caspian and Transbaikal), the growth of international relations, and the use of modern means of communication currently force us to maintain constant anti-epidemic vigilance.

Treatment: antibacterial drugs, the choice and route of administration of which, as well as the volume of therapy in general, are determined by the form of the disease, the severity of its course, and the nature of complications.

Cholera is an acute infectious disease
human cervical disease caused by
mine is Vibrio cholera.
Until the beginning of the 19th century. cholera was endemic to
areas located in the river valley. Ganges and his
tributaries Cholera was brought to Europe in 1816.
before 1917, 5 million people were ill in Russia,
half of them died. Total in literature
7 devastating cholera pandemics have been described.
The beginning of the 7th pandemic dates back to 1961. General
the number of only bacteriological confirmed
new cases of disease, according to WHO, to the present	Rice. 3.1. Buboes on the leg of a plague patient
By the beginning of 1984 the number exceeded 1.3 million people.

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The clinically pronounced form of the disease is characterized by the sudden onset of copious liquid bowel movements and vomiting, leading to severe dehydration and desalination of the body, impaired circulation, cessation of urination, decreased skin temperature, the appearance of convulsions, cyanosis (bluish discoloration of the skin and mucous membranes), profound metabolic disorders and depression functions of the central nervous system up to the development of coma. Probability of death is 60–80%.

Cholera pathogens enter the external environment with feces, and less often with vomit of people.

The main way cholera spreads is through contaminated water, as well as consumption of contaminated food and poor personal hygiene. Flies also contribute to the spread of infection.

Treatment is aimed at restoring the water-salt balance, i.e. the patient is administered a large amount of water-salt mixtures and glucose in different ways: through the mouth, using a gastric tube and intravenously. In addition, antibiotics are used for treatment.

Anthrax is a disease from a group of particularly dangerous infections that affects farm animals and humans.

The causative agent, anthrax bacillus, has vegetative and spore forms. The vegetative form is resistant to unfavorable environmental conditions, but quickly dies when heated (instantly when boiled) and under the influence of disinfectants. Spores formed outside the body are extremely resistant to any influence; they remain viable and virulent for decades.

The source of infection are domestic herbivores - sheep, goats, cows. Cases of infection from sick people have not been described. Anthrax bacillus is excreted in the urine, feces and saliva of animals. Human infection is possible through contact with sick animals, processing of anthrax animal raw materials, through finished products made of leather, fur, food and air, and through contact with contaminated soil. There may be cases of laboratory contamination with anthrax, as well as infection through receipt of contaminated correspondence. Agricultural workers, farmers, veterinarians, and workers at agricultural-related enterprises are at increased risk of infection.

The disease is recorded in zoonotic foci of anthrax in all climatic zones; found everywhere. Sporadic cases or outbreaks are possible. Anthrax in humans can occur in cutaneous, pulmonary and intestinal forms. The incubation period usually lasts 2–5 days.

The onset of the disease in the pulmonary form resembles ARVI, but after 3–5 days acute respiratory failure develops, which leads to shock and death of the patient.

In the cutaneous form, skin itching and a rash initially appear in the area of ​​the entrance gate of infection. After 2–5 days, the rash turns into blisters, then the tissues die, a black scab is formed, surrounded by edema and secondary small blisters (Fig. 3.2). Sepsis (general blood poisoning) is possible.

Chapter 3. Biological hazards and protection against them

With the development of the intestinal form, the character-
we have cutting pain in the abdomen, vomiting bile with
admixture of blood, significant swelling of the blood
cervical, frequent loose stool mixed with
blood, severe intoxication of the organs is expressed
nism, the development of “acute” syndrome is possible
The probability of death is 100%.
First time vaccinated against anthrax
French microbiologist Louis Pasteur.	Rice. 3.2. Neck lesion
Control measures: prescribing antibiotics,	in a patient with anthrax
disinfection, immunization of persons exposed to

posing an occupational risk of infection, as well as timely destruction of the corpses of dead animals (they are burned or buried deeply after treatment with quicklime).

Human anthrax diseases are observed in almost all countries of the world. In developed countries, the disease occurs in isolated cases, mainly associated with the processing of imported raw materials of animal origin. The attention of the world community to this disease at the beginning of the 21st century. due to a number of terrorist attacks that occurred in 2001 and 2010. in the USA (distribution of letters containing anthrax pathogens).

Smallpox natural- a severe, highly contagious human disease.

Smallpox epidemics, which were devastating, were described in the 6th century. AD in Italy, France and other countries. In the XVII–XVIII centuries. In Europe, 10 million people suffered from smallpox every year and about 1.5 million of them died. In the 16th century Spanish colonialists brought the disease to America, where it caused severe epidemics among the Indians. Later it appeared in Australia and Oceania. The English doctor Edward Jenner in 1796 made the world's first smallpox vaccination. In the USSR, smallpox was eradicated by 1937 thanks to compulsory smallpox vaccination.

The incubation period lasts 12–15 days. Symptoms: chills, very high body temperature, headache, dizziness, vomiting, loss of appetite, constipation; characterized by pain in the lower back and especially in the sacrum; loss of consciousness, delirium, shortness of breath are possible.

After a slight decrease in temperature, a small, pinpoint rash appears throughout the body, especially abundant on the face and hands. Similar rashes cover the mucous membranes of the mouth, nose, and conjunctiva of both eyes.

with smallpox

Rice. 3.3. Girl from Bangladesh

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As a result, the patient has difficulty breathing through the nose, photophobia, lacrimation and salivation develop, hoarseness and cough appear.

The rash very quickly transforms into compactions, then into blisters and pustules, which dry out and form crusts (Fig. 3.3). Following this, itching of the skin and mucous membranes appears. Patients, unable to withstand the itching, tear off the crusts, under which bleeding and suppurating ulcers form. After the crusts are rejected, reddish spots remain, which over time acquire a brown tint, and in those places where the skin lesions were the deepest, round scars (pockmarks) are formed that last a lifetime.

As a result of damage to the conjunctiva, blindness can occur. The probability of death is 95–100%.

There is no specific treatment for smallpox yet. Prescribing antibiotics prevents the development of purulent processes that are possible when the disease is complicated by a secondary infection.

In 1980, at the XXXIII session of the World Health Assembly, the eradication of smallpox from the Earth was announced. However, due to the existence of so-called monkeypox, which in an unimmunized population can lead to an outbreak of smallpox in humans, the problem cannot be completely closed. Therefore, in the Russian Federation, immunization against smallpox is mandatory.

Viral hepatitis. Hepatitis is an acute infectious disease primarily affecting the liver. To date, 5 forms of hepatitis have been studied: A, B, C, D, E. The incidence of hepatitis remains high everywhere. With a sharp deterioration in sanitary and living conditions, especially in the event of an emergency, the incidence of hepatitis becomes epidemic.

Viral hepatitis A(infectious). The causative agent is the hepatitis A virus (HAV), which is quite resistant to adverse environmental conditions. The source of infection is a sick person; he is contagious from the end of the incubation period. The incubation period usually lasts 28–30 days. Hepatitis A is also called jaundice or Botkin's disease.

The mechanism of transmission of infection is water-food. Human susceptibility to HAV is high, especially in children aged 2 to 10 years.

The disease is characterized by a sudden onset, fever, and general weakness. The patient is worried about lack of appetite, nausea, and abdominal pain. After about a week, jaundice develops and the urine becomes dark color, and the feces become discolored, liver function is impaired (determined by laboratory tests), the liver increases in size.

Viral hepatitis B(whey). The causative agent is the hepatitis B virus (HBV), which is quite stable in the external environment.

Chapter 3. Biological hazards and protection against them

The source of infection is a sick person. Infection occurs when the virus enters the blood directly through injection or through mucous membranes or damaged skin.

The onset of the disease is gradual; decreased appetite; the temperature is normal or slightly elevated; abdominal pain, nausea; sometimes joint pain. After a few days, as with hepatitis A, jaundice develops. The disease can develop into chronic hepatitis, cirrhosis, cancer or necrosis (death) of the liver, fulminant course of the disease, and coma are possible.

Viral hepatitis D(delta hepatitis). According to the epidemiological features, hepatitis D is similar to hepatitis B, but it is milder. The only source of pathogens is a sick person or a virus carrier. The disease is transmitted through infected blood during transfusion, through direct contact with a patient or virus carrier, or through transfusion of whole blood substitutes.

It is widespread, like other forms of hepatitis. Complications: in approximately 50% of cases, the disease becomes chronic, and liver cirrhosis is possible.

Treatment of viral hepatitis is carried out only in a hospital. There is no specific therapy; treatment measures consist of following a regimen, diet, and prescribing symptomatic medications. Bed rest is mandatory in all cases, since restriction of movements reduces metabolism and energy costs. Semi-bed rest is allowed only if the general condition improves at the end of the icteric period in very mild forms of the disease.

Tick-borne encephalitis- acute infectious disease of the brain. The causative agent is a filterable virus. The carriers of the virus in nature are pasture and forest ticks. The carriers of the virus are chipmunks, mouse-like rodents, moles, hedgehogs, and some species of birds (buntings, hazel grouse, blackbirds, nuthatches, etc.). The virus enters the human bloodstream through the saliva of an infected tick during a bite.

The incubation period lasts 10–14 days. Tick-borne encephalitis, caused by the activity of ticks, has a pronounced seasonal character - from early spring (the first bites may appear as early as the first warm days of April) until mid-summer, and sometimes until late autumn, until the end of November.

Most often, the disease begins suddenly: a severe headache appears, body temperature rises to 39–40 ° C, nausea, vomiting, general stupor, seizures, and unconsciousness occur. Paralysis of the limbs may develop. After recovery, strong and long-lasting immunity is developed. For a long time, the patient continues to have headaches and symptoms of weakness of the nervous system.

The main treatment for tick-borne encephalitis is anti-encephalitis gamma globulin, preferably human, with a high content (titer) of antibodies. In addition, oxygen, restorative and symptomatic therapy, and spinal puncture are used. If necessary, it is also provided intensive therapy and resuscitation.

Tularemia is an acute infectious natural focal disease of humans and animals. The causative agent is a bacterium that is resistant to unfavorable external factors.

Basics of life safety

her environment; retains its properties for a long time at low temperatures, but dies instantly when boiled.

Under natural conditions, the source of infection is rodents and hares. The pathogen is transmitted by ixodid ticks, mosquitoes, and fleas. A person becomes infected with tularemia, usually as a result of:

direct contact with rodents (vole, water rat, muskrat, hamster, etc.);

contact with blood or tissues of infected wild animals;

arthropod bites;

eating animal meat that has not been subjected to prolonged heat treatment;

drinking contaminated drinking water;

inhalation of mixed dust.

Tularemia is not transmitted from person to person. Depending on the conditions of infection and the method of transmission of the pathogen, vector-borne, waterborne, commercial, agricultural, household, food and hunting types of epidemic foci of tularemia are distinguished.

The incubation period lasts from 2 to 10 days, but usually 3 days. Symptoms and course: sudden onset, chills, enlarged and painful lymph nodes, their suppuration; sweating, headache, muscle pain, especially in the calf, enlarged liver and spleen. Pulmonary and intestinal, as well as generalized forms of the disease are possible.

Treatment: antibiotics, symptomatic therapy, administration of a killed vaccine.

Typhus. The causative agent is Provacek's rickettsia. The source of infection is a sick person, the transmitter is a body louse. Infection occurs when excrement from crushed lice gets into the bite site or when dust containing excrement from infected lice is inhaled.

Typhus is common on all continents except Australia. In Russia, the disease appeared about 800 years ago and has always accompanied national disasters - famine, wars, etc. In 1900–1906 in St. Petersburg, 95% of the sick were among the poor. In 1918–1922 In our country, about 20 million people have suffered from typhus.

The disease is recorded in endemic foci with cool climates in lice-infested population groups; Outbreaks typically occur in overcrowded housing among refugees as well as disaster-affected populations.

After a 1–2 week incubation period, the patient suddenly develops a fever, chills, headache, generalized pain, a state of complete physical and neuropsychic relaxation (prostration), and possible delirium. After 5–6 days, a rash appears on the skin of the trunk and extremities (except for the face, palms and soles), which later takes on the character of pinpoint hemorrhages. Complications: acute vascular failure, gangrene, renal failure, coma. After many years, relapses of the disease are possible. The probability of death is 40%.

Treatment: chloramphenicol, tetracycline antibiotics, as well as supportive and symptomatic therapy.

Chapter 3. Biological hazards and protection against them

Typhoid fever is an acute infectious disease that affects only humans. The causative agent of the disease is the typhoid bacillus, which is moderately resistant to adverse environmental conditions, but dies instantly when boiled.

The source of infection is a sick person who sheds bacilli or carries bacteria. The pathogen is transmitted through fecally contaminated food and water. The average duration of the incubation period is 14 days.

In the 19th – early 20th centuries, typhoid fever was one of the most common and severe infectious diseases in all countries of the world, especially in cities, due to their rapid growth, crowded population and low sanitary and hygienic level. Almost every natural disaster (crop failure, famine, earthquakes), as well as wars, was accompanied by epidemics of typhoid fever. Currently, the incidence of typhoid fever is recorded in almost all countries of the world; it varies widely: from 0.5–0.6 in economically developed countries to 30–70 cases per 100 thousand people and higher in developing countries.

The disease usually begins gradually. The temperature rises slowly, remains high for 2–3 weeks, then slowly decreases. The patient is worried about nosebleeds, headache, lack of appetite, abdominal pain, loose stools; Pink spots appear on the skin of the body. Possible states of severe depression, complete immobility, delirium with visual hallucinations. Complications: intestinal bleeding, perforation (breakthrough) of the intestine, pneumonia. Treatment: antibiotics, blood transfusions, intravenous administration of nutritional mixtures.

Epidemic process

Any epidemic occurs in the presence of a so-called “epidemic chain”, which consists of the following links: 1) source of infection, 2) transmission routes, 3) human population susceptible to this infection.

First link. The source of infection is, first of all, people who suffer from one or another infectious disease, as well as carriers of bacilli. The latter include healthy people who have pathogenic microbes in their bodies. This microorganism does not cause harm to the person himself, but it is capable of entering the external environment and can often cause the spread of infection. Usually, bacilli carriage occurs after a person has suffered an acute infectious disease or as a result of contact of healthy people with sick people. In the latter case, people who do not get sick due to immunity are still carriers of the infectious agent.

Second link. Pathogenic microorganisms are transmitted through the external environment in the following ways:

a) water - drinking contaminated water, washing fruits and vegetables with it, washing dishes, washing and swimming in bacterially contaminated water bodies, etc.;

b) nutritional - eating contaminated food products; c) aerogenic - inhalation of air containing dust particles or aerosols,

Basics of life safety

e) contact - through direct contact with the patient or with objects with which he came into contact.

The third link is the susceptibility of people to this infection. When an infectious disease occurs in a community, not all people usually become ill. Due to the presence of innate or acquired immunity, some part of the population does not get sick. This different susceptibility depends on the type of infection, the implementation of preventive measures (vaccinations, etc.), and also, to a large extent, on the living conditions of people and their material well-being.

Since any epidemic occurs only if the indicated three links are present, then when the chain is “broken”, or one of the links is switched off, the epidemic itself stops. Particularly dangerous infections, due to their specificity, form the basis of biological weapons of mass destruction, therefore their study is of military importance.

Measures at the site of bacteriological damage

In the event of a outbreak of a particularly dangerous infection, to prevent the spread of the disease beyond the boundaries of the biological focus, a set of treatment and preventive measures is carried out and quarantine is established.

Quarantine is a system of organizational, regime, administrative, economic, sanitary and hygienic, anti-epidemic and treatment and preventive measures aimed at complete isolation of the epidemic focus of especially dangerous infections, the zone of biological contamination and the subsequent complete elimination of the consequences of infection.

Armed guards are installed at the outer borders of the quarantine zone and traffic is regulated. The population is divided into small groups, contacts between which are reduced to a minimum. It is not allowed to leave apartments and houses unless absolutely necessary; food, water and essential supplies are delivered by special teams. The removal of animals and property is prohibited. Entry and entry may only be permitted to special civil defense units and medical personnel to provide assistance in eliminating the consequences of emergency situations.

Objects that find themselves in the quarantine zone are switching to a special operating regime with strict compliance with anti-epidemic requirements. Workers' rest, as well as meals, are organized in groups in specially designated areas. Work stops in the quarantine zone educational institutions, entertainment institutions

and retail outlets.

IN in cases where the identified type of pathogen does not belong to the group of particularly dangerous infections and there is no threat of mass diseases, the imposed quarantine is replaced by observation.

Observation is a system of measures for medical surveillance of isolated healthy people who have had contact with patients with quarantine infectious diseases and who are leaving the quarantine zone.

IN The following security measures are carried out in the observation zone:

entry and exit, as well as the removal of property without prior disinfection and permission from epidemiologists, is limited to the maximum extent possible;

medical control over food and water supply is being strengthened;

Chapter 3. Biological hazards and protection against them

movement in the contaminated area is limited, communication between individual groups of people is normalized, etc.

In the observation and quarantine zone, from the very beginning of their formation, special measures for disinfection and destruction of insects and rodents are carried out: disinfection, disinfestation and deratization.

Disinfection is the destruction of pathogens of infectious diseases at environmental objects.

Preventive disinfection- disinfection, which is carried out constantly, regardless of the presence of infectious diseases. The purpose of preventive disinfection in emergency situations is to prevent the spread of pathogens of infectious diseases, as well as their accumulation on external objects.

Current disinfection- disinfection, which is carried out repeatedly before hospitalization of the patient in order to prevent the spread of pathogens from his immediate environment into the external environment.

Final disinfection- disinfection by disinfection teams, carried out once after hospitalization or in the event of death of an infectious patient. The purpose of final disinfection is to prevent the spread of the pathogen through objects and things used by the patient.

Disinfection is based on the use of physical means and methods to destroy or remove pathogens. Physical disinfection factors include: high temperature, water, ultraviolet radiation, direct sunlight, etc.

The most common disinfectants are bleach, chloramine, hydrogen peroxide, formaldehyde. A 0.5% solution of chloramine is used to treat hands, and a 5% solution is used to disinfect secretions of infectious patients.

Main methods and objects of disinfection:

immersion in a disinfectant solution followed by washing dishes from secretions (feces, vomit, urine, sputum);

boiling tableware that is not contaminated with laundry secretions;

soaking in a disinfectant solution and then washing laundry contaminated with secretions;

Irrigation of garbage pits, garbage cans;

burning of garbage and everything that cannot or is impractical to process;

filling garbage with disinfectant solution;

wet cleaning with a rag soaked in a disinfectant solution (furniture, door handles, equipment).

To destroy household lice and fleas, things are treated with hot air in disinfection chambers.

Flies and cockroaches, soiling their paws in the secretions of patients, can carry pathogens of typhoid fever, dysentery, cholera, tuberculosis, and plague. Lice transmit typhus and relapsing fever; fleas - plague; mosquitoes - malaria.

Basics of life safety

Deratization is a set of measures aimed at combating rodents, sources or carriers of infectious diseases. Thus, rats transmit more than 20 infectious diseases. At the same time, they are very prolific: one pair of rats can produce up to 800 individuals in a year.

The most dangerous rodents for humans are mice and rats. Wild rodents carry pathogens such as plague and tularemia. To combat them, drugs under the general name raticides are used. An example of raticides is zoocoumarin. Raticides pollinate burrows, passages, and objects frequently visited by rodents.

Timely removal of garbage and waste prevents the emergence and spread of infectious disease pathogens and their carriers.

Particularly dangerous diseases of animals and plants

Particularly dangerous infectious diseases of animals - diseases that are characterized by the presence of a specific pathogen, cyclical development, the ability to be transmitted from an infected animal to a healthy one and take on the character of an epizootic.

According to the breadth of distribution, the epizootic process occurs in three forms: sporadic incidence, epizootic, panzootic.

Sporadia is the lowest degree of intensity of the epizootic process; these are isolated or infrequent cases of manifestation of an infectious disease, usually not related to each other by a single source of the infectious agent.

An epizootic is a widespread spread of infectious animal diseases on a farm, district, region, country, characterized by a common source of the pathogen, simultaneity of damage, frequency and seasonality. Represents the average degree of intensity (tension) of the epizootic process.

Panzootic is the highest degree of development of epizootic; it is characterized by an unusually wide spread of an infectious disease, covering one state, several countries, and a continent. In recent years, examples of such panzootics are avian influenza, an intestinal infection of unknown etiology. Thus, when cattle became infected with spongiform encephalitis in England, emergency measures had to be taken to prevent the infection from spreading to the European continent: hundreds of thousands of animals were destroyed, and the country suffered enormous damage amounting to billions of dollars.

Depending on the method of transmission, infectious diseases are divided into five groups:

1) nutritional (transmitted through soil, feed, water) - for example, foot and mouth disease, anthrax, glanders and brucellosis;

2) respiratory or aerogenic (transmitted airborne) - for example, parainfluenza, sheep and goat pox, carnivorous plague;

3) transmissible (transmitted by blood-sucking insects) - for example, tularemia, infectious anemia of horses;

4) infections whose pathogens are transmitted through the outer skin without the participation of carriers, for example, tetanus, rabies, cowpox;

5) infections with unknown routes of infection.

Chapter 3. Biological hazards and protection against them

Foot and mouth disease is a highly contagious, acute viral disease of artiodactyl domestic and wild animals. Symptoms: fever and ulcerative lesions of the mucous membrane of the oral cavity, skin of the udder and limbs.

Cattle and pigs are most susceptible to foot and mouth disease. The source of the pathogen is sick animals and virus carriers. They excrete the virus in saliva, milk, urine and feces, resulting in infection of premises, pastures, water sources, feed, and vehicles.

Humans are of great importance in the spread of the foot and mouth disease virus. After contact with animals, it can travel long distances, spreading the virus.

Classic swine fever- an infectious highly contagious viral disease of domestic and wild pigs of all ages and breeds. High-breed animals are more susceptible to the virus.

The main source of the infectious agent is sick animals and virus carriers. Infection occurs when they are kept together with healthy animals, as well as when feeding infected feed. Plague can occur at any time of the year, but more often in the fall, during mass movements, sales and slaughter of pigs. In new outbreaks, 95–100% of unimmunized livestock become ill, and animal mortality reaches 100%. There is no specific treatment; sick animals are immediately killed and the corpses are burned.

Pseudoplague of birds is a highly contagious viral disease of birds of the order Gallinae, affecting the respiratory and digestive organs, and the central nervous system.

The source of the infectious agent is sick and recovered birds, which secrete the virus with all their secretions, excreta, eggs and exhaled air. Infection occurs through food, water, air when healthy and sick birds are kept together. Morbidity is up to 100%, mortality is 60–90%.

No specific treatment has been developed. Sick birds are killed and burned, and the farm is quarantined.

Particularly dangerous plant diseases is a disruption of the normal metabolism of a plant under the influence of a phytopathogen or unfavorable environmental conditions, leading to a decrease in plant productivity and a deterioration in the quality of seeds (fruits) or to their complete death.

Epiphytoty is the spread of infectious plant diseases over large areas over a certain period of time.

The most harmful epiphytoties are observed in years with mild winters, warm springs and humid, cool summers. The grain yield is often reduced by up to 50%, and in years with favorable conditions for the fungus (phytophthora, ergot) the crop shortfall can reach 90–100%.

Late blight of potatoes- a widespread harmful disease that leads to crop failure due to the premature death of the affected tops during the formation of tubers and their massive rotting in the ground. The causative agent of late blight is a fungus that persists in tubers throughout the winter. It affects all terrestrial organs of plants. The disease is detected, as a rule, in the second half of summer. Yield losses reach 15–20% or more.

Basics of life safety

Yellow rust of wheat- a harmful common fungal disease that, in addition to wheat, affects barley, rye and other types of cereals. Basically, infection occurs in the presence of moisture and a temperature of +10...+20 °C. In areas with dry and hot climates it is very rare.

Stem rust of wheat and rye- the most harmful and widespread disease of cereals, most often affecting wheat and rye. The causative agent of the disease, a fungus that destroys the stems and leaves of plants, has high fertility, so the disease spreads very quickly, in a short time, affecting large areas of crops. The most dangerous foci of stem rust of wheat and rye are located in the Kuban and Stavropol Territory.

Questions and tasks

1. Biological hazards and their causes. Give examples of biological hazards.

2. Causative agents of infectious diseases. Features of the action of bacteriological agents. Signs of the appearance of funds.

3. Epidemic, pandemic, epizootic, epiphytotic.

4. Characteristics of dangerous and especially dangerous human infectious diseases.

5. Actions of people in the focus of bacteriological damage.

6. Characteristics of the main anti-epidemic measures.

7. Using the literature, analyze the main epidemics, epizootics and epiphytoties over the past 5 years in your region.

Occurs when exposed to various pathogens. Disruption of the normal functioning of the medical, social, technological, communal and agricultural spheres can be provoked by both an individual prion and multicellular parasites.

Biological hazard is characterized by varying degrees and depends on the extent to which the harmful factor can harm a person.

Common forms of dangerous biological agents include the following organisms:

• various microbes;

• biological hazards may involve scorpions. Their bites are not only very painful, but can also be fatal. Even some types of caterpillars and centipedes can cause severe pain and the formation of blisters on the skin, and in some cases provoke death (this applies to the so-called electric caterpillars, which are found in Central America);

• wild bees and wasps;

• leeches. When they bite, the wound can become infected, which leads to complications;

• worms that cause disturbances in the functioning of the digestive system, as well as anemia and general weakness;

• poisonous snakes and lizards. It is worth noting that biological hazard can only be determined by lizards, which are common in desert areas. But given their slow movement, the number of people affected is miniscule.

A great threat to human life and health are various marine organisms - sharks, rays, jellyfish, as well as mammals (wild boars, lions and tigers, foxes and jackals, whose bites can cause rabies).

Threatening biological hazards are not only microorganisms, insects or animals of various levels of organization. These are also various poisonous plants that exhibit their damaging effects when touched or eaten. Among these plants are mangrove and black poisonous trees, carasco shrubs, and varnished wood in Japan.

There are many more plants with stinging hairs. They cause pain when touched. Unpleasant sensations are associated with the action, but these plants do not pose a threat to life. Despite this, contact with them should be avoided.