Chemical method of deratization. Types of effective rat repellents Physical and chemical properties

Chemical Deratization Method- The essence of the chemical method is to poison rodents with toxic substances - rodenticides (from the Latin rodentis - gnawing and caedo - I kill). These substances act by ingestion or by suffocation (fumigants).

There are basically three ways to kill rodents with rodenticides:

1. the use of poisoned baits, which use food and water;
2. pollination of burrows, passages, paths and other places visited by rodents with poisons. Rodents, passing through pollinated areas, come into contact with poison, which sticks to their fur. Cleaning themselves of adhered particles, the animals swallow the poison.

   With these two methods, the poison enters the intestinal tract of rodents, then, when absorbed, has a toxic effect. Poisons used in poison baits and for pollination must evaporate slowly;

3. aeration is a method in which gaseous chemicals entering the lungs of rodents cause their death.

Of the poisons that act when introduced into the digestive tract, the most commonly used are zinc phosphide, zoocoumarin, ratindan, and less often - monofluorine, glyfluorine, fluoroacetamide, the drug plant origin- red sea onion. Previously, phosphorus and arsenic, strychnine, fluoride and sodium fluorosilicate were widely used.

Below is a description of the most important distinctive properties of modern rodenticides.

Zinc phosphide. It is a dark gray powder, tasteless, with a faint odor of garlic. Insoluble in water and alcohol. Melting point 420°C. Used in the form technical product, which contains 14 - 18% phosphorus, 70 - 80% zinc and up to 6% other compounds. The active principle of zinc phosphide is phosphine (hydrogen phosphide), which is released from poisoned bait under the influence of hydrochloric acid, which is part of the gastric juice. Phosphine is toxic to nervous system, blood and internal secretion.

Zinc phosphide is highly toxic not only to rodents, but also to other animals, as well as humans (lethal dose for rats 15 - 30 mg, for mice 3 - 5 mg), so special care is required when using it.

Zinc phosphide is well eaten by rodents. In baits for killing rats and mice it is used in an amount of 3%. Due to the decomposition of zinc phosphide in acidic environment It should not be used with rye bread, sour dough and other quickly souring products. Due to the decomposition of zinc phosphide, baits containing it last 2-3 days, and therefore they must be used immediately after production. To increase the effectiveness of zinc phosphide in the manufacture of baits, you need to use products that increase the acidity of the stomach contents of rodents (porridge, white or gray bread).

Zinc phosphide should be stored in a dry, well-ventilated area. For baits, you should use only dry preparation.

Zookoumarin (warfarin). It is a white crystalline powder without taste with a weak specific odor. Almost insoluble in water, soluble in acetone, less soluble in alcohol, poorly soluble in ether. Melting point 162°C.

Zookoumarin is a slow-acting poison and, when administered once to rodents, is relatively low-toxic, however, it has a pronounced cumulative property (accumulates in the body), so small doses taken several times over a number of days ensure the death of rodents. Thus, for the death of a gray rat, a four-time dose of 0.25 g of the drug or a five-time dose of 0.2 mg is sufficient. This drug is dangerous for pets and humans, but in much higher dosages. For humans, the lethal dose is 400 - 1000 mg for a body weight of 60 kg.

The death of rodents after taking zoocoumarin occurs within 7 to 10 days. The drug causes slow blood clotting and also increases the permeability of the walls of blood vessels, which causes hemorrhage. Animals die from a decrease in the number of red blood cells and hemoglobin in the blood, which leads to oxygen starvation of tissues.

To prepare poisoned baits and pollination, 0.5% dust is used, in which one part by weight of zoocoumarin is mixed with 200 parts of starch (1:200). The drug is added to the food base in an amount of 5%. Zookoumarin dust can withstand long-term storage and, when kept in a dry room, does not lose its toxic properties for several years. Zookoumarin can be used in food and water baits and for pollinating surfaces and burrows; rodent trail.

IN last years There have been reports that certain populations of gray rats and house mice have been identified that are resistant to anticoagulants, and in particular, to zoocoumarin.

Difenacin (ratindan). Light yellow crystalline powder, tasteless and odorless, insoluble in water, soluble in organic solvents, acetic acid. Melting point 146 - 147°C. Refers to anticoagulants.

Ratindane is a mixture of diphenacin mixed in a ratio of 1:200 (0.5%) with starch. To kill a gray rat, a four-time dose of ratindan 2 mg or diphenacin 0.01 mg is sufficient. In terms of its raticidal properties, ratindan is approximately 25 times more toxic than zoocoumarin.

Ratindan is used to prepare poisoned food baits, as well as to pollinate burrows, exits from them, and travel routes of rodents. After eating baits with ratindan, rats die within 5 to 8 days. To prevent accidental poisoning, ratindan is available in the form of a blue-tinted powder. When stored in a dry place for 2 years, ratindan does not lose its toxic properties.

To prepare food poisoning baits, ratindan is added to the food base in an amount of 3%. A single lethal dose of ratindan for mice is 4 mg, for rats - 6 - 8 mg.

Bactocoumarin. It is a mixture of zoocoumarin with a bacterial culture (see below). According to some authors, it is more effective than the separate use of zoocoumarin and bacterial culture.

Sodium salt of zoocoumarin. Free-flowing yellow powder, odorless. It dissolves well in water and is used mainly in aquatic baits and pastes.

Monofluorine. Crystalline substance, pinkish in color. Soluble in ethyl alcohol, acetone, partially in hot water, insoluble in cold water. Melting point 134.5 - 135.5°C. Refers to organofluorine, acute and highly toxic poisons. The lethal dose for the gray rat is 15 mg/kg, the house mouse - 15.5 mg/kg, voles - 3 - 4 mg/kg. The death of rodents occurs after 3 - 4 hours. To exterminate rodents, 1% of the drug is added to the bait. Monofluorin is not allowed to be used for pollinating rodent burrows and paths.

Glyftor. The liquid is light Brown with a characteristic odor, soluble in water and alcohol. Toxic drug, LD60 for rats is about 100 mg/kg. Intended mainly for combating gophers in the form of baits with oats. Oats are soaked in a glyfluor solution. Take 0.3 g of glythor for 10 liters of water. Glythor is flammable. Shelf life 2 years.

Fluoroacetamide. It looks like white or grayish crystals. It dissolves well in water. The death of rats when eating bait containing 1% fluoroacetamide occurs in a very short time. The drug is recommended for use in poisoned baits, for treating grain and in water baits; it is prohibited to use it for pollination. Due to its high toxicity, working with fluoroacetamide requires special precautions; it cannot be used on food enterprises. At long-term storage the drug remains active.

Red sea onion. Cultivated along the Mediterranean coast and on its islands. In the Soviet Union, sea onions grow on the Black Sea coast of the Caucasus. Large, fleshy pear-shaped bulbs reach a mass of 2.5 kg. The outside of the bulb is covered with dark scales, under which there is juicy, odorless pulp, but a disgusting bitter taste, which is why this plant is not eaten by animals, except rodents, which do not have a gag reflex. The active principles are glycosides - scillitin, scillipicrin and spillin. For rats, the lethal dose of these glycosides is 0.1 - 0.2 mg.

Sea onions are consumed in the form of mashed mass, dried prorosh, juice and extracts. Various baits are prepared from the mass and powder, and bread is soaked with extracts or juice. The death of rodents after taking a lethal dose occurs within 12 - 48 hours. For humans, sea onion is lethal at a dose of 1.2 - 1.5 g.

Not all sea onion bulbs are poisonous, as some contain insufficient amounts of the active substance. This reduces the value of the plant. In addition, the drug quickly decomposes, and therefore it can only be used fresh. The plant is difficult to cultivate, and therefore it is relatively expensive.

Sea onions should be stored in dry rooms, without sudden changes in temperature.

To exterminate rodents, fumigants are also used, such as sulfur dioxide, carbon dioxide, chloropicrin, methyl bromide, and hydrocyanic acid preparations.

Sulfur dioxide- a gas with a sharp, prickly odor, heavier than air (air density 2.264). The boiling point is about 10°C, it liquefies easily, the relative density of liquid sulfur dioxide at a temperature of 20°C is 1.49. Sulfur dioxide is highly soluble in water. The resulting sulfurous acid corrodes metals, discolors fabrics, and damages and destroys equipment. At relatively low humidity and high air temperature, it is possible to minimize the destructive properties of sulfur dioxide. The latent heat of evaporation of liquid sulfur dioxide is large, so when the gas leaves the cylinders, it may freeze and stop entering the room. Sulfur dioxide is produced in metal cylinders with a capacity of 10 to 50 kg.

If sulfur dioxide is used, the indoor air temperature must be at least 20°C. For gassing buildings, sulfur dioxide is standardized at 100 g of liquid per 1 m 3 of premises. Exposure is 3 - 4 hours. For aeration of sea vessels, the consumption rate is 80 g/m 3, exposure at 20°C is 6 hours, at 30°C - 5 hours. Rats and mice die after 15 - 20 minutes if there is 0 in the air .1% sulfur dioxide. When gassing rodent burrows, the concentration is increased to 100 g of liquid anhydride per 1 m 3 at 20°C; exposure 3 - 4 hours.

Carbon dioxide. Gas is colorless and odorless. The density is 1.5 times the density of air; 1 liter of gas weighs 1.830 g. It turns into a liquid state at 0°C and a pressure of about 3.6 MPa (36 kgf/cm2), the critical temperature is 31.4°C. When it flows out into the air from a cylinder under pressure, it turns into a solid snow-like mass, which, quickly evaporating and bypassing the liquid state, lowers the temperature to - 78 ° C. Once compressed into a dense mass, “dry ice” remains in air for quite a long time, since it requires a large amount of heat to turn into gas.

Carbon dioxide is mainly used in refrigerators. Treatment with this drug can be carried out if there are products in them, the quality of which does not change due to its use. Dosage 500 - 700 g per 1 m 3; exposure 48 hours

Chloropicrin (trichloromethane, nitrochloroform). In its pure form it is a colorless, easily mobile oily liquid with a sharp pungent odor, boiling at 112 - 113°C. The industry produces 96% of the technical preparation, which is yellowish in color. Chloropicrin is heavier than air; it evaporates readily at room temperature, producing irritating vapors with a characteristic unpleasant odor. At a concentration of 1 - 2 g/m 3, rats die after 25 hours, at a concentration of 20 - 30 g/m 3 - after 15 - 10 minutes.

Chloropicrin is often used in field conditions for the extermination of rodents in burrows, while liquid chloropicrin is administered in an amount of 1 - 2 g per burrow.

To introduce chloropicrin into the entrances of burrows, cotton swabs on sticks are used. Sometimes sawdust or sand is pre-wetted with chloropicrin and the holes of the burrows are filled with it. After administering the drug, the passages into the holes are tightly covered with earth or other available material and then carefully trampled down. Special equipment for dosed administration of chloropicrin into the burrows of field rodents is also recommended.

Methyl bromide. Chemically pure methyl bromide (methyl bromide) under normal conditions is a colorless gas that turns into a transparent liquid at a temperature of 4°C. The relative density of liquid methyl bromide is 1.732. Pure methyl bromide is odorless, slightly soluble in water, and soluble in alcohol, ether, gasoline, and oils. Technical methyl bromide is used for carbonation. It is a colorless or slightly yellowish liquid containing at least 99.5% of the main substance. Methyl bromide vapors have a high penetrating ability, due to which it quickly spreads throughout the premises, freely penetrates into all cracks, soft equipment, etc. Compared to other fumigants, it is less absorbed by furnishings and materials and is quickly removed from them during ventilation. In the gaseous state at the concentrations and exposures used for carbonation, methyl bromide does not have a destructive effect on metal, paints, fabrics, Construction Materials. Available in metal cylinders.

Hydrocyanic acid preparations. The active principle of all drugs in this group is hydrogen cyanide, which has a boiling point of 26°C and a relative gas density of 0.9. Its good solubility makes it difficult to use hydrogen cyanide as a fumigant. Freezing point - 14°C. The substance is a light gas, is easily sorbed and therefore does not penetrate into materials well. It is one of the most toxic fumigants and has a rapid paralyzing effect. Hydrocyanic acid preparations are extremely toxic to humans. For aeration, hydrocyanic acid preparations are used - cyclones B and D. Cyclone B is diatomaceous earth granules impregnated with liquid hydrocyanic acid and packaged in tin, hermetically sealed containers. closed jars containing 200 g of hydrocyanic acid. Cyclone D is discs made of pressed paper pulp, sawdust or other porous, inert carriers, impregnated with liquid hydrocyanic acid and packaged in cans containing 1 - 1.5 kg of hydrocyanic acid. The dynamics of the release of hydrocyanic acid from cyclones depends on the room temperature and the thickness of the disks and granules. Cyclones B and D are produced with an admixture of a tear alarm.

Preparation of poisoned baits. The quality of poisoned baits is determined by the correspondence of the dosage to the degree of toxicity of the poison and its uniform distribution throughout the food base. An increase in the concentration of rodenticides against established standards leads to the fact that rodents refuse to take such baits. We should also not forget that baits with excessive amounts of poison are more dangerous for people and pets. Along with this, an insufficient concentration of poison leads to the development of defensive reflexes, after which rodents distinguish rodenticide and do not take the poisoned bait for some time, even if the food base changes.

When formulating poisoned baits, the concentrations of rodenticides are calculated so that each portion of the bait is toxic to rodents. Due to the fact that rats and mice have different resistance to poisons, and in addition, with a single meal, rats eat more poison than mice, when using certain rodenticides it is necessary to prepare different baits for rats and for mice.

Uniform distribution of poisons in the food base is achieved by thorough mixing or grinding components bait. Rodenticides that are insoluble in water must be mixed especially thoroughly. In some cases, flour or starch paste, as well as vegetable oil, are used to attach insoluble particles of poison to the food base. Reliable mixing is ensured by the use of simple mechanization in the form of mixing machines.

The degree to which poisoned baits are eaten depends on the attractiveness of the products taken to prepare the bait, the culinary processing and appearance of the bait, and especially the degree of masking of the poison in the food base. When choosing food products First of all, it is necessary to take into account the biological feeding characteristics of individual rodent species. As a food base, it is necessary to take food that is characteristic of the rodent species being destroyed. The food base varies depending on local conditions. To make a rational choice, you should constantly monitor and study the eating habits of certain types of foods by rodents. This largely applies to black rats, who are more picky about their food.

There is no need to consume expensive gastronomic products, as this leads to an unnecessary increase in the cost of pest control and waste of valuable products such as smoked meats, cheeses, canned food, candies, and cookies. Rodents do not need this food; they willingly eat rye or wheat bread, various cereals and all kinds of porridges, wheat, oat, pea and rye flour, raw and boiled vegetables, minced meat (sausage) and fish. To prepare minced meat, you can successfully use cheap horse meat, meat from unused domestic and wild animals. Can also be applied food waste from meat and fish factories. At the same time, all products must be fresh. Rodents avoid spoiled, sour, rotten or moldy food.

Rats always prefer baits with sufficient moisture content. To make food baits more attractive, it is recommended to flavor them with a small amount of salt, sugar, and fat; Rodents react especially well to sunflower oil. The appearance of the baits should be the same as the usual food found by rodents.

Bread baits. First, bread crumbs are prepared, for which the bread is slightly dried so that it crumbles easily and the crumbs are homogeneous. The finished crumbs are weighed and poured into an enamel basin or bowl; rodenticide, sugar and butter are placed there exactly by weight. All components are thoroughly mixed with a wooden spatula until a homogeneous mass is obtained.

Lures on porridge. Salt and sugar are dissolved in water. Cook the cereal in this solution until you get a thick porridge. To form uniform grains, spread the porridge in a thin layer on the table or in bowls. When the porridge has cooled, it is weighed and thoroughly mixed in an enamel bowl with weighed out oil and then rodenticide.

Meat or fish baits. Minced meat is made from meat pulp, offal, cheap boiled sausage or gutted fish using a meat grinder. The weighed minced meat is thoroughly mixed with rodenticide, bread crumbs and butter.

Flour baits. The flour is mixed with rodenticide, then the mixture is mixed with salted water to which oil has been added. When preparing cookies, the dough with poison is rolled out with a rolling pin to a thickness of 0.5 cm, then cut into pieces measuring 3x3 cm. The pieces are fried in oil. These cookies can be stored in a dry place for 2 - 3 months.

Preparation of baits from minced meat and flour. The flour is mixed with rodenticide, and the minced meat is mixed with oil. Then both mixtures are placed in a mortar or basin and ground until a homogeneous consistency is obtained.

Vegetable baits. Boil washed potatoes, carrots, beets or other vegetables in a small amount of salted water. Finely chopped, uniform and cooled pieces of cooked vegetables are mixed with oil and rodenticide.

Grain baits prepared in two ways:

1. when using insoluble drugs (zinc phosphide), they are glued to the grain. To do this, the grain, freed from impurities and debris, is placed in a saucepan and thoroughly mixed there with hot 4% starch paste and rodenticide. Then the grain is cooled and dried. After this, the grain is mixed with oil;
2. when using soluble poisons, the grain is soaked or boiled in toxic solutions.

Pastes. A very convenient form of deratization agents. They are stored for a long time (up to a year) and, due to their portability, are easily transported over long distances without reducing their toxic properties. Pastes are used in smaller quantities than poisoned baits. They can be prepared centrally and used not only at production sites, but also in expeditionary conditions.

Green baits. in winter and in early spring When there are no green plants rich in vitamins in nature, green baits are successfully used. They are prepared with sprouted oats, vegetables and succulent plants. Plants or vegetables are pollinated with insoluble raticides or soaked in water-soluble poisons.

Paraffin briquettes. It is prepared as follows: the main bait product (dough or crushed oatmeal) is thoroughly mixed with granulated sugar, salt, vegetable oil and poison (zinc phosphide, zoocoumarin, ratindan), and the listed recipe components are added sequentially. The prepared mixture is poured with TU-ORU 40-55 paraffin melted in a water bath (for laboratory purposes). The mixture is poured in a thin layer onto a baking sheet and after hardening (but not completely, but while it has some elasticity) is cut with a knife or mold into pieces weighing 100 g. Then 5 - 10 pieces are packed in parchment or wrapping paper, on which the name of the bait is placed, the date and place of manufacture, period and storage conditions and are marked with the word POISON in bright paint.

Biscuits. It is made from flour as follows: the poison is dissolved in warm water, tinted red with eosin (1 g of dye is taken per 1 liter of water), sugar and salt are dissolved there. The dough is kneaded using the solution, vegetable oil is added, it is rolled out in a layer of 0.5 cm and flat cakes weighing 20 - 30 g are cut. The biscuits are baked in drying cabinet at an initial temperature of 50°C and a final temperature of 140°C for 6 hours, and then dried, packaged and labeled in the same way as briquettes.

Biscuits and briquettes should be stored in a dry place at room temperature. Shelf life up to 1 year.

In table 10 lists the most common recipes for poisoned baits. The conditions for their use are also indicated there.

Laboratory for the production of poisoned baits. Poisoned baits, as well as baits for fishing gear, must be prepared in a specially equipped laboratory room. To do this, select an isolated, dry, bright room. Under no circumstances should this room be located near a disinfectant warehouse where odorous substances are stored. The walls of the laboratory are painted with light oil paint, the floors are covered with linoleum or painted with oil paint. There should be no gaps in the floor. Laboratory room doors must be tightly closed and have secure locks. To dispense baits to disinfectants, a well-closing window is installed in the wall or door.

The laboratory is provided with sufficient electric lighting and equipped with a running water supply and a drain sink. Availability is desirable gas stove. In the absence of gas, it is necessary to have electric stoves or an oven with a stove for cooking food. Above the cooking device you need to equip exhaust hood. Packaging and mixing of toxic materials with food products should be carried out in a convenient place for work. fume hood. The hood must completely and quickly remove all gaseous toxic substances. The fume hood table is covered with linoleum or galvanized iron.

The laboratory should have two tables: one upholstered with galvanized iron for preparing and cutting food products, the second - a regular office table. Poisonous materials should be stored in a metal box with a lock; the box should have the inscription “Poisons” and an image of the emblem (skull and bones).

Poisons must be in a tight, serviceable container, equipped with a label that clearly indicates the name of the poison and the date of its receipt by the laboratory. It is advisable to have a refrigerator for storing food.

Laboratory equipment consists of scales, a meat grinder, a crumb grater, basins, buckets, pots, bowls, frying pans, a mortar, a sieve, knives, spoons, metal and wooden spatulas kitchen boards, spatulas, measuring utensils, rubber gloves, safety glasses, respirators, oilcloth aprons, hand washing brushes, workwear, towels. The following are posted in a visible place in the laboratory: a) instructions for the use of rodenticides; b) recipe for poisoned baits); c) a table on first aid for poisoning with toxic substances used.

The preparation of poisoned baits and packaging of poisonous materials is carried out by a laboratory assistant. Persons under 18 years of age, as well as pregnant women and nursing mothers are not allowed to do this work. Entry of unauthorized persons into the premises where poisoned baits are produced is strictly prohibited. You are not allowed to drink, smoke or eat in the laboratory.

Baits are consumed on the day of preparation. To do this, they are prepared in the amount of daily requirement. You should not prepare bait based on perishable products for future use, especially in summer. Weighing, packaging and mixing of rodenticides is carried out in a fume hood, and care must be taken that the poisons are not sprayed. Poisonous baits and dry poisons for pollination are issued against receipt with an exact indication of the mass of the substance and the date of release. The distribution of poisoned baits and poisons to unauthorized persons is not permitted.

Tables and dishes must be washed after preparing poisoned baits. hot water with 2% sodium bicarbonate. Utensils intended for preparing poisoned baits cannot be used for other household needs, especially cooking and feeding animals.

Upon completion of work, the laboratory technician must take off his overalls in the laboratory, wash his hands with soap, wash his face and rinse his mouth.

All incoming and dispensed rodenticides as part of poisoned baits and powders for pollination, as well as food baits for fishing gear and preliminary feeding, are subject to daily recording in special logs.

Control of poisoned baits. To determine the toxicity, and therefore the effectiveness, of the rodenticides used, it is recommended to systematically test poisoned baits. Control of baits can be carried out both chemically and biologically. Biological control is more important, and in the absence of a chemist on staff, it is more accessible. For biological control, it is necessary to catch and keep rats and mice in laboratory conditions. The use of white laboratory rats and mice for control purposes is not recommended.

On the eve of testing the poisoned bait, the animals are placed in cages one by one and their rations are reduced. On the day of the experiment, rats are given 20 g, and mice - 5 g of the tested bait. Control animals are fed similar food, i.e., non-poisoned baits. The product is considered effective if at least seven out of ten experimental animals died. After 2-3 weeks, baits with other raticides can be tested on surviving animals.

Chemical control of the content of rodenticides in baits is carried out analytically, checking the compliance of the amount of poisons with the recipes specified in the current instructions for use of a particular drug.

Use of poisoned baits. Before laying out poisoned baits, you should make sure that there are rodents and determine their type. It is also necessary to find out where they nest, what exits from their burrows to the surface they use, outdoors or indoors. The presence of rodents and their type are determined by objective indicators: catch, monitored dust areas, detection of droppings, fresh gnaws.

After determining the type of rodents and finding out their habitats, poisoned baits are laid out in burrows, bait boxes, and in some cases openly.

Laying out poisoned baits in burrows. Poisoned baits are placed in inhabited, or so-called “living holes,” that is, in those holes and crevices used by rodents. The habitability of burrows is determined by temporarily closing them by sealing them with paper or plugging them with tow, rags, paper, and in open areas by filling them with a small amount of earth or sand. If after 1 - 2 days after this the exits from the burrows become free (open), then they are considered residential.

It is recommended to remove as much food and waste as possible 1 - 2 days before laying out baits and place them in containers inaccessible to rodents. In service and office premises, you should check for food residues in individual cabinets, tables or wastepaper baskets. It is also advisable to remove water.

The baits are placed as deep as possible into the exits of holes and crevices, placed in paper bags or “pounds”. To lay out bulk bait, you can use a clean spoon. An average of 20 - 25 g of poisoned bait is placed in each hole of a rat hole, and 2 - 3 g of poisoned bait in a mouse hole. It is not advisable to sprinkle bait in large quantities. To avoid damage and soaking of baits, they should not be placed in the passages of holes in deep basements with high groundwater. Baits with slow-acting zoocoumarin that accumulates in the body must be laid out 3-4 days in a row or 2-3 times every other day. After 5 - 8 days, depending on the degree of population, the object is re-checked and the poisoned bait is again laid out in all newly opened burrows.

Laying out poisoned baits in bait boxes. This method, like the previous one, is quite effective; In addition, it is safe for others. Bait boxes prevent the accidental release of poisonous baits. The designs of bait boxes vary. The simplest and most convenient bait boxes are wooden or plywood rectangular boxes 25 cm wide, 40 cm long and 15 cm high. Dimensions may vary slightly. The upper wall is arranged in the form of an opening door with lugs for a lock. Square or round holes with a diameter of 7 - 8 cm are cut out in two side walls. Bait boxes must be clean, free of foreign odors. Boxes should not be painted; outside of work, they should be stored separately from odorous disinfectants.

The poisoned bait is placed on the bottom of the bait boxes in the amount of 50 - 100 g (2 - 4 tablespoons). When using baits with zinc phosphide and fluoroacetamide, the boxes are locked. They place boxes near the exit points of rodents, along their paths, which most often run along walls, objects or cargo standing in one place for a long time, in quiet, secluded places. For every 50 - 70 m2 of area inhabited by rodents, one bait box should be placed. 2 - 3 days after laying out the bait, the boxes are checked, and if it turns out that rodents eat the poisoned bait, then the same bait is added. If this bait is ineffective, it is changed.

Bait boxes are especially convenient when working in large warehouses or open areas. In these cases, appropriate warning notices are placed on the bait boxes.

Open layout of poisoned baits. In warehouses and production facilities where there are few people and no pets, poisoned baits with zoocoumarin, ratindan and other rodenticides that are low-hazard for people and pets can be openly laid out. In these cases, it is better to place poisoned baits in paper bags or “pounders”, on which warning labels “Poisonous bait” are placed. Such

The “pounders” are left in the same places where the bait boxes are placed. Each “pound” holds 15 - 20 g of bait for rats and 2 - 3 g for mice.

One portion of the bait is placed on 10 - 15 m2 of the area inhabited by rodents. The next day after laying out the baits, they check and remove uneaten baits, and if they are eaten well, add fresh poisoned bait. For convenience in checking and collecting residues, you can make chalk marks on the walls near the places where baits are laid out.

Pre-feeding. Rodents are very careful; when they encounter foods that are unusual for them or familiar food in new places, they are wary of such food. In these cases, it is recommended to accustom rodents to the products from which poisoned baits are made. Feeding or the use of “preparatory baits” is carried out in those places where poisoned baits are supposed to be laid out. If bait boxes are used, then feeding is also done in them.

The unpoisoned bait is laid out in such a way that it is enough for several rats and they do not look for food in other places. On the first day, 70-100 g of food is usually left. If the rodents immediately take the complementary food well, then in subsequent days the portions are increased without changing the type of bait. If the rodents refuse this type of food within 10 - 12 days, the products are changed. Better feeding carry out 5 - 7 days in a row or, in extreme cases, 3 - 4 times every other day. By the end of the specified period, rodents usually get used to the places where unpoisoned bait is laid out, become less cautious and willingly eat food.

After this, poisoned baits are prepared on the same food base and laid out in the same places and in the same places. residual quantities Oh. The use of a feeding method increases the efficiency of using poisoned baits. The seemingly wasteful consumption of products pays off with successful results and a further reduction in the cost of poisoned baits.

Placing poisoned baits made on perishable products in burrows, crevices and other openings, as well as openly in places where there are no rodents, in the expectation that rodents may be poisoned at a later date (during subsequent settlement), is not practical. It should be borne in mind that baits attract rodents for no more than 5 - 7 days after their preparation, and in summer time, when food spoils faster, in an even shorter time. Along with this, to prevent the settlement separate rooms or buildings, as well as certain areas of the territory, and to exterminate existing rats and mice, so-called long-term points or permanent sites of poisoning of rodents. For this purpose, portable or stationary bait boxes are used. Stationary bait boxes are wooden chests (70x50x20 cm) with a lid lined with tin (to protect against rain and snow) and with holes on the adjacent side walls of the box.

Long-lasting baits are also placed in trays, pipes, and boxes that are inaccessible to other animals.

In order to ensure their long-term effect, poisoned bait is placed in bait boxes prepared on grain (oats, barley, wheat), cereals, bread crumbs and other products that do not lose their attractiveness to rodents for a sufficient time (15 - 30 days). Anticoagulant poisons (zoocoumarin, ratindan) are more often used as rodenticides. In stationary bait boxes, the poisoned bait is placed in feeders (saucers, jars), and in portable ones - directly on the bottom of the box. 200 - 250 g of bait are placed in each box. The safety of the bait is checked after 15 - 30 days, and if there are visible signs of the presence of rodents - every 2 - 3 days. As rodents eat the poisoned bait, it is added or replaced. Typically, on objects with an area of ​​up to 1000 m2, 8-10 boxes are placed, and in rooms with a larger area, 4-5 boxes are added for every 1000 m2.

Briquettes and biscuits are more effectively used in damp areas - basements, sewer wells, as well as on sea and river vessels.

Liquid baits. Rats absorb large amounts of moisture, which is why water is used as bait. In places where rodents do not find water, drinkers with water pollinated with rodenticides are placed. By absorbing poison-pollinated water, rats ingest rodenticide. Poisons used for pollination must be insoluble in water and light (with low relative density). Water-soluble rodenticides are not used in liquid baits, since rodents recognize toxic solutions and usually do not drink them. Heavy preparations (with a high relative density) are ineffective with this method of application: rats carefully drink only the top layer of water and do not take the rodenticide in the sediment.

Zinc phosphide, zoocoumarin, and ratindan are used to pollinate water. As drinking bowls, clay or other feeders for laboratory animals, flower trays, and other stable dishes 4–6 cm high are used. Water is poured into the drinking bowls in a layer of 1 cm. For every 100 cm2 of water surface, 0.5 g must be taken for pollination. zinc phosphide, 3 - 5 g of zoocoumarin dust or ratindan.

When pollinating, you need to ensure that the rodenticide powder is distributed evenly over the entire surface of the water. Pollination is carried out immediately before placing drinkers. For pollination, special dusters or rubber bulbs with a tip are used. To spray the rodenticide evenly, insert a strip of thick paper into the outer part of the spray tip. In the absence of these devices, pollination can be carried out with gauze bags made from two layers of gauze. To uniformly distribute the rodenticide throughout the water in the form of a film, lightly rock the drinkers. When using zinc phosphide as a pollinating agent, drinkers with it are placed in bait boxes and this drug is used with all precautions.

Pollination with rodenticides. In addition to baits, poisons are quite successfully used to pollinate places frequently visited by rodents. This method is based on the fact that animals, passing through pollinated areas, stain their fur, paws, and muzzle with poisonous powder. When rodents lick their outer coverings, the poison enters the mouth and is then swallowed. When shaking, the poison can enter the lungs. Unlike the bait method, when success is largely determined by how full the rodents are and how they are attracted to the bait, pollination is more effective way, since the poison penetrates the body of both hungry and well-fed rodents.

The effectiveness of this method largely depends on the choice of rodenticides and the technique of their application, as well as the correct choice of places for pollination. This method uses water-insoluble and low-hygroscopic poison powders. Due to the fact that small particles of poison stick to the fur of rodents more easily than large ones, it is advisable to grind and sift them before using coarse-grained preparations (for example, zinc phosphide).

The most suitable rodenticides for pollination are zoocoumarin, ratindan, and zinc phosphide. For these purposes, zoocoumarin and ratindan are used in the form of dust, and zinc phosphide is used in pure form or mixed with fillers in a 1:1 ratio. Talc, starch, road dust, flour and other inert powders can be used as fillers.

Exits from burrows, paths, garbage receptacles and other places where droppings and gnawing are found are subjected to pollination. When pollinating exits from burrows, powders should be introduced first of all into the openings of inhabited burrows; It is necessary to dust not only the external openings of the exits, but also the deep parts of the passages. An average of 1 - 2 g of zinc phosphide powder is used per hole; zoocoumarin and ratindane dusts are recommended to be used in an amount of 2 - 5 g.

Approximately the same amounts of rodenticides are spent on 1 m 2 of open floor surfaces when treating paths and other places where rodents are. In these cases, after pollination there should remain a uniform, clearly visible thin layer rodenticide. In dry places, poisons act for quite a long time. Repeated treatments are carried out after 12 - 15 days.

Pollination is also used with cotton wool, tow, rags, and paper, which are used to cover the exits of burrows. Rodents, penetrating into exits closed in this way, throw out pollinated barriers and quickly and easily come into contact with poisonous powders. In these cases, poisons fall directly onto the muzzle and into the oral cavity of rodents. During periods of greatest reproduction of rats (early spring and autumn), it is advisable to place pieces of pollinated cotton wool or tow near the exits of their burrows, which rodents use to build their nests. This way can act not only on adult rodents, but also on young animals in nests.

It is most convenient to pollinate the outlet openings using a rubber bulb that has a special tip equipped with a dispensing device. When pollinating burrows in the field, backpack fur pollinators with tips can be used. Pollination of rodent trails, trash cans and others open places It is also produced with gauze bags made from two layers of gauze.

To pollinate burrows and paths of rodents, poisons should be used in small quantities, since this method leads to contamination of the environment with rodenticides and increases the danger of the work being carried out for persons who are constantly in the treated area.

Artificial nesting boxes. In the fight against common voles on the territory of vegetable farms, artificial nesting boxes or shelters are successfully used - boxes measuring 20 x 40 x 50 cm or tubes made of roofing felt, rolls of paper 20 - 30 cm long and 5 - 7 cm in diameter. Hay and straw are placed in the nesting boxes or any rag dusted with zoocoumarin (50 g) or ratindan (30 g) per 0.5 kg of nesting material. In summer, shredded carrots with 1% are placed in the nesting boxes. vegetable oil and 3% ratindane.

Rodenticide rotation. With frequent and prolonged use of the same rodenticides in poisoned baits or during pollination, rodents become “accustomed” to them, i.e., specific resistance to poisons increases, and conditioned defensive reactions are developed, which consist in the fact that rodents They quickly begin to recognize the poison they encounter and stop taking poisoned baits with it. This applies to all currently used rodenticides, with the exception of zoocoumarin and ratindan. In order not to reduce the effectiveness of the chemical method, it is necessary to use poisons in a certain sequence, observing the order. On the other hand, frequent alternation of poisons and baits from perishable foods (bread, porridge, meat, fish) causes alertness of rodents, which negatively affects the quality of extermination work. In this regard, as the main means of control, it is necessary to use long-lasting baits with zoocoumarin and ratindan, and baits with zinc phosphide and other acute poisons no more than 3-4 times a year during the autumn peak of abundance and spring breeding rodents, as well as for epidemiological indications.

Deterrents. Rodents appear to develop an aversion to certain odors and avoid them. This led to the search for deterrent (repellent) substances to protect individual buildings or premises from rats, mice, and voles. Previously, we tried to use plants for these purposes - black root, comfrey, meendera, as well as many chemicals, including naphthalene, mercoptane, nicotine sulfate, creosote, coal and wood tar products, kerosene, essential oils.

TO gas method deratization is used mainly to exterminate rodents on vehicles, in particular on ships, in railway cars, and, more recently, on airplanes. In populated areas, gas is mainly produced by free-standing elevators, grain warehouses, refrigerators, and mills. In the field, gases are used to kill rodents directly in their burrows.

For carbonation, you can use substances that at the temperature of their use have sufficient high pressure saturated vapors and allowing to achieve the required gas concentration for effective exposure. Such gases can be sulfur dioxide, carbon dioxide, hydrocyanic acid preparations, methyl bromide.

When using gaseous drugs, adsorption and condensation of toxicants occurs on surfaces. The amount of adsorbed substance at a given temperature increases with increasing gas pressure, however, with increasing temperature or at constant pressure, adsorption decreases. On the contrary, a decrease in temperature leads to an increase in the amount of adsorbed substance. Therefore, a decrease in temperature during the holding period leads to additional condensation of the toxicant on surfaces.

This phenomenon during aeration causes the need to extend the ventilation period.

In the process of aeration, which consists of three stages (preparation, holding, degassing), along with the direct task of ensuring a certain concentration for a certain time (holding), after the end of the latter, the reverse problem of removing the drug occurs

(degassing) from the treated room, from surfaces and objects located in this volume.

Preparing buildings or vehicles for gas treatment consists mainly of isolating them and clearing the premises from people, animals, plants, and when using some fumigants (hydrocyanic acid, chloropicrin) from food and water. For the purpose of insulation, windows and doors are tightly closed, and cracks in windows, doors, ceilings, floors, and walls are sealed with paper strips. The gas must freely penetrate underground, into all blind places and compartments where rodents may be located.

Then toxicants are introduced into the room, and depending on their mass, the drugs are introduced from above, if they are heavy, or from below, if they are lighter than air. After reaching the required gas concentration, the room with it is kept for a certain time. The holding time depends not only on the properties of the gas, but also on the temperature. The final stage of gas treatment is degassing, which is carried out mainly by ventilation and increasing the temperature in the room. Degassing is carried out until the dose of the toxicant reaches the maximum permissible concentration for a particular drug.

Gasification of sea transport and fishing vessels. The gas method of treating sea vessels is used in the following cases: there is a death of rodents; a high number of rodents was noted; the ship has arrived or is leaving for ports that are unfavorable for quarantine diseases; It is not possible to destroy rodents and household insects by other means.

Gas treatment of ships is carried out after unloading. In case of plague, the ship is placed under gas with cargo. For gas treatment of sea vessels, methyl bromide, hydrocyanic acid and sulfur dioxide are used (their description is given above). The main fumigant is methyl bromide, and in its absence, hydrocyanic acid and sulfur dioxide are used.

Gas treatment is carried out by gasification teams of basin and port SES or corresponding units of the territorial sanitary service. The detachments are staffed with: a disinfection doctor (gassing specialist) - 1, a laboratory doctor or chemist with higher education- 1, paramedic - assistant epidemiologist - 1, disinstructor - 2 and disinfectors - 6 people. From the squad are allocated responsible persons for accounting, storage and use of gaseous toxic substances.

The aeration squad must be equipped with equipment for qualitative and quantitative determination of the fumigant and have a first aid kit. For the entire duration of gasification work, the detachment is provided with transport for transporting disinfectants, pesticides and equipment. The personnel of the gasification squad are provided with special clothing in accordance with the approved standards for the free issuance of special clothing, special footwear, safety equipment, etc.

The need for gas treatment of a ship is determined by representatives of the sanitary-quarantine and disinfection departments of basin and port SES or territorial sanitary services carrying out sanitary supervision in a given port. If necessary, representatives of anti-plague laboratories (stations) are involved. The sanitary and quarantine department gives the captain of the ship an order to gas the ship and notifies the dispatch service of the port, shipping company, etc. about this.

All preparatory work on the ship (sealing, lifting packaged gas onto the deck, etc.) is carried out by the ship's crew. At the end of the preparatory work, the boiler fireboxes are turned off or turned off. The chief mate, together with the doctor, walks around the ship's premises and checks whether all crew members have gone ashore. The chief mate is the last to leave the ship and signs the removal of the crew.

The protection of the vessel from entry by unauthorized persons not participating in the gassing is entrusted to the administration of the ship, for which the captain appoints watchmen for the entire gassing period who are on shore. The captain of the ship is responsible for providing safety instructions to crew members taking part in preparatory work, standing watch at the gangway, mechanics and electricians when checking the operation of the ship's ventilation, lighting and heating systems during degassing and the performance of activities by all crew members after degassing. and commissioning of the vessel.

Providing first medical aid to persons participating in the gassing and checking the implementation of personal and public safety measures by the detachment personnel is assigned to the doctor of the gassing detachment. To ensure the greatest possible safety, the doctor, before starting gassing, indicates the place where the first aid kit will be located; interviews members of the gassing squad about their health status; sick people and persons showing signs of alcohol intoxication are not allowed to work; checks the serviceability of gas masks, indicates exit routes from gas-filled rooms; provides all the possibilities for minimizing the time spent by crew members in gas-filled rooms, etc.

A warning board is installed near the ship's ladder with the inscription “Entry prohibited. Life threatening!". The inscription should be clearly visible and illuminated at night. Flags are raised on the ship to indicate that gassing is being carried out on the ship.

A disinfectant on duty remains at the ship's berth and is replaced according to schedule. The disinfectant still has spare gas masks (3 - 6 pieces). If necessary, the disinfector accompanies the crew member on watch to turn on the warning lights on the decks or in cases where the watch during degassing monitors the operation of the heating and ventilation system being turned on.

Before gassing, the vessel must be carefully sealed by the crew under the supervision of an assistant epidemiologist. Holds with wooden flooring are additionally sealed with 2 - 3 layers of tarpaulin or synthetic films. Ventilation holes and pipes are clogged with rags, tied with tarpaulin covers or synthetic film; portholes, hermetic doors, light and ventilation openings are closed on all wings. Small holes and cracks are sealed with paper smeared with paste, grease or technical petroleum jelly.

When using sulfur dioxide, to avoid corrosion, all metal parts of machinery, equipment and ship trim are wiped dry with a rag and lubricated with protective mineral (non-drying) lubricants or oils, or technical petroleum jelly.

Checking the seal, supplying gas to the premises and handing over the vessel should, as a rule, be carried out during daylight hours. For Arctic ports and in exceptional cases, carbonation is allowed at night. In this case, it is necessary to ensure sufficient lighting in all ship premises and ensure external lighting of the ship and the berth for the entire gasification period.

During the gasification of ships, the port administration is obliged to allocate a berth at a distance of at least 50 m from residential and industrial premises. There must be a watch room on the berth at least 30 m from the ship. Gassing of ships in a roadstead or near a breakwater is prohibited.

At the end of the gasification, the detachment doctor fills out a report in two copies. One copy is handed over to the ship's administration, which, on the basis of it, receives a deratization certificate. At the same time, the captain is given instructions on the mandatory measures to be carried out by the forces and means of the ship’s crew after its gas treatment.

To carry out aeration, the calculation of the fumigant dosage is carried out taking into account the degree of sealing of the ship, the air temperature in different groups of ship premises (holds, engine room, service and living quarters); the purpose of treating each isolated compartment (deratization, disinfestation) and the degree of loading of the premises with objects that absorb gas.

The work plan should include measures aimed at accelerating the degassing of the ship: full use of the ship's ventilation and heating systems, removal of soft bedding onto the deck if they do not require treatment, use for additional ventilation of shore installations, etc. Particular attention should be paid to devoted to measures for the safe use of fumigant on this vessel. The possibilities of supplying gas to holds, engine and boiler rooms from open decks, through hoses are taken into account, and the routes of disinfectants when distributing the drug throughout the premises are specified.

The effectiveness of deratization (and disinsection) depends on three conditions: the lethal concentration of the fumigant in the air after completion of the sorption processes; action time (holding time) and temperature inside the carbonated room.

It is necessary to distinguish between the concepts of dosage and gas concentration. Dosage is the calculated amount of fumigant supplied to the premises. Concentration is a real, actual amount of fumigant, which is determined analytically, by one of the methods, by a chemist of the aeration squad in a certain room at a certain time. Both quantities are expressed in grams per cubic meter (g/m3).

The actual fumigant concentration is usually less than the calculated gas dosage. When using methyl bromide, it can be 50 - 70%, when using hydrocyanic acid and sulfur dioxide - 20 - 50% of the calculated value. Poor sealing dramatically reduces the actual gas concentration. If sealing cannot be ensured, it is not practical to gas the vessel. The actual concentration of gas in the air is also reduced due to the sorption of the fumigant by furnishings. Methyl bromide is less sorbed than hydrocyanic acid and sulfur dioxide.

The number of sampling points for the gas-air mixture and the frequency of determining the gas concentration in each isolated compartment are determined by the doctor and chemist in relation to each type of vessel, and depends on its tonnage and design. At least 2-3 samples are taken from each group of isolated rooms (holds, machinery, service rooms, etc.) during the holding period. The first determination of the fumigant concentration is carried out no earlier than 30 minutes after stopping the supply of methyl bromide and sulfur dioxide or after the complete release of hydrocyanic acid from cyclones D and B. The last determination is carried out 30 - 60 minutes before the end of exposure.

The chemist is obliged to organize the collection of gas-air samples in such a way as to give the squad doctor a fairly complete description of the fumigant concentration in individual compartments over time.

Temperature conditions above 20°C are the most rational for all three fumigants. Before gassing, the ship's heating system must be turned on until the indoor temperature is not lower than 20° C (preferably 26 - 27° C). At this initial temperature, a more complete and quick selection hydrocyanic acid and better distribution of sulfur dioxide and methyl bromide throughout the premises. In addition, it should be taken into account that the air temperature, depending on meteorological conditions (especially in Arctic ports) and the latent heat of evaporation of the fumigant, decreases during the exposure time (by 5 - 15 ° C).

In the case of gassing due to epidemic indications of unladen ships, the dosages of fumigants are doubled and the holding time is extended to 24 hours. When gassing loaded holds, the holding times are increased to 48 hours.

After determining the actual concentration of the fumigant, the doctor of the aeration squad and the chemist make amendments to the calculated treatment regime: they clarify the exposure or add the fumigant to those rooms where its insufficient concentration was determined. If necessary, the sealing of individual rooms is increased, etc.

To take gas-air samples in order to determine the actual concentrations of the fumigant in the ship's premises before introducing gas into the holds, engine room, service and other isolated compartments, rubber hoses with a diameter of 4 - 7 mm are installed in places farthest from the gas release points. The outer end of the hose is brought out to the open deck and clamped tightly with a clamp. The hose outlets are tightly sealed. The intake of the gas-air mixture is carried out using aspirators with a capacity of 5 - 10 liters. Using clamps, the selection speed is adjusted. The first 2 - 3 liters of air from the rubber hoses are drawn idle to clean the hoses from the gas accumulated in them.

To kill rats outside aerated rooms (on open decks, in boats, chests, etc.), poisoned baits and rodent fishing gear are laid out before aeration, and, if possible, the decks are rolled down with hot water, especially under pipeline casings.

In cases where there is no need to leave soft equipment and bedding (mattresses, pillows, etc.) in the ship's premises, these items are taken by the ship's crew onto the deck to the place indicated by the doctor and covered with a tarpaulin. Bedding can be gas-treated under a tarpaulin, or in one of the well-ventilated areas of the superstructure.

The distribution of the fumigant throughout the premises is carried out taking into account the physico-chemical properties of the pesticide (relative density) and the form of its use (cyclones and liquefied gas in cylinders). Heavy gases - methyl bromide and sulfur dioxide - are supplied to the compartments from the upper decks. Hydrocyanic acid preparations must be distributed directly on the lower decks of each compartment. The following should be taken into account:

1. It is most rational to supply gas from cylinders to the holds and other rooms of the ship from open decks without entering the premises, using rubber hoses connected to the cylinder fitting using adapters and union nuts. Cyclones are thrown into the hold from the open deck, but in such a way that the disks or granules fall to the bottom of the hold;
2. in cases where the design features of the ship do not allow the supply of gas from the decks using hoses, the cylinders are installed in the gas room near the exit in such a way that after opening the cylinder valve, disinfectors can quickly leave the premises;
3. on a large ship, it is advisable to insulate large compartments and gas them separately. First, open the valves of the cylinders installed in the rooms located below the main deck. The distribution of cyclones begins from the lowest deck, then moves upward towards the exit to the main deck. The superstructure rooms are gased depending on design features the vessel according to the same principle - from the places furthest from the entrance to the rooms with access to the open deck;
4. In all cases, the machine and boiler room is isolated from other rooms and gases separately. Gas is supplied from the cylinders from above through skylights or the cylinders are installed on the top grille. The cyclones are thrown from the upper grates in such a way that the discs or granules reach the lowest deck of the engine room;
5. When gassing empty holds with a depth of more than 7 m, it is advisable to organize mixing of the methyl bromide or sulfur dioxide entering them for 30 - 60 minutes. To do this, before gassing, portable electric fans are installed in the holds, which are turned on at the right time from the main deck.

All work with methyl bromide, hydrocyanic acid and sulfur dioxide is carried out in a different grade for each gas. Work with methyl bromide is carried out in gas masks with a filter box of grade A (brown). The box is designed to operate for 20 minutes at a methyl bromide concentration in the air of 33 g/m. All work with hydrocyanic acid and sulfur dioxide is carried out in gas masks with a filter box of grade B (yellow). Time protective action boxes for at least 30 minutes at a concentration of hydrocyanic acid of 10 g/m 3 . The protective action time of the box at a sulfur dioxide concentration of 8.6 g/m is 45 minutes.

Gas masks are assigned individually to each worker. Gas mask helmets are carefully selected according to the size of the head. At least two people work simultaneously at each cylinder and when distributing the hydrocyanic acid preparation.

Torch liquefied gas from the cylinder, depending on the temperature inside the room, the liquid fumigant is ejected at a distance of up to 3 m. The valve of the cylinder opens completely, so the cylinder must be placed so that the stream of fumigant does not splash the walls, deck and equipment.

Cylinders with liquefied sulfur dioxide are installed with the neck down, securing them in wooden shoes. A hose with a spray nozzle is suspended at a distance of 1 m from the floor with the torch directed obliquely from top to bottom. Cylinders with methyl bromide are placed with the neck up or slightly tilted towards the valve.

Cans with a cyclone are opened with special circular knives on the open deck near the hold (when it is gassed) or in the ship's premises directly at the place where each can is distributed. Opening cyclone cans in the same cabin is prohibited due to accumulation large quantity hydrocyanic acid in this room.

After administering the fumigant, the detachment goes ashore, takes off their gas masks, then everyone washes their hands and face, and rinses their mouths. The detachment doctor checks the list of members of the gasification team and gives instructions on the procedure for degassing the vessel and further work.

The effectiveness of gas treatment is determined by the actual death of insects and rodents of the local population and using biocontrol. Biocontrol (red cockroaches, at least 5 females with ootheca in gauze bags;

At least 5 bed bugs and their eggs; rat fleas at least 10 pieces in test tubes tightly closed with gauze; black or gray rats in tops of 1 - 3 pieces) before gassing, it is spread throughout the premises and placed in places farthest from the gas release points. Insects are placed under pillows, in boxes, etc. Depending on the tonnage of the vessel and its design features, the number of places for laying out biocontrol may vary, but in such a way that biocontrol is left in all isolated compartments. It is advisable to leave biocontrol at the points where the gas-air mixture is taken. Test tubes with insects and tops are labeled.

Biocontrol from the premises is collected 1 - 2 hours before the end of degassing, at the same time female cockroaches with oothecae and other insects found on the ship are selectively selected. Rodents are handed over to the anti-plague laboratory or the department of especially dangerous infections of the SES.

Accounting for the death of insects and the final assessment of the effectiveness of disinfestation is carried out one day after the start of exposure. Accounting for the death of rodents and assessment of the effectiveness of deratization is carried out immediately after decontamination. It must be borne in mind that the death of insects after the use of methyl bromide may not occur immediately after its action, and the deep paralysis of insects after the action of hydrocyanic acid imitates their death.

After the exposure period has expired, disinfectors led by a doctor, wearing gas masks, climb on board and begin depressurizing the vessel from top to bottom: they remove the canvas covers from the ventilation columns. Without entering the premises, open the doors facing the deck to remove the bulk of the gas.

After l½ - 2 hours from the start of ventilation, disinfectors in gas masks enter the premises, open the remaining doors, portholes and ventilation openings. With the permission of the doctor, a mechanic and 1-2 sailors in gas masks go down into the engine room together with the disinstructor to start the machine, force ventilation, heating and turn on the electric lighting.

First of all, measures are taken for intensive ventilation of the machine and boiler room. If the holds are covered with metal covers, then crew members are involved in lifting them. This work is carried out in gas masks under the supervision of a gassing squad doctor.

To speed up the degassing of the ship, in addition to natural ventilation of all ship premises with the maximum opening of all possible openings, it is necessary to actively use the ship's artificial ventilation and heating systems. It is advisable to use portable fans, especially in those areas of the ship where there is no artificial ventilation. It is advisable to use on-shore powerful air handling units and mechanical heaters. Degassing occurs most quickly after using methyl bromide, then hydrocyanic acid and sulfur dioxide.

The ship's degassing regime is planned by a doctor and an assistant epidemiologist in such a way that during the cold season, especially in northern ports, the air temperature inside the ship's premises does not decrease with open ventilation openings and doors below certain values: when using methyl bromide - 20 ° C, hydrocyanic acid and sulfur dioxide - 25°C. In the summer, the indoor temperature should exceed the ambient air temperature. On ships where, for a number of reasons (boiler repairs, malfunction of the heating system, refusal of the ship administration to ensure uninterrupted heating operation, etc.) it is not possible to maintain the temperature regime - gas method cannot be applied.

During unfavorable meteorological conditions during degassing of the vessel, doors and ventilation openings are periodically opened and closed. The time for which the ship's premises are opened and closed is regulated by the air temperature inside the ship's premises.

1 - 2 hours before the end of degassing, disinfectors with disinstructors in gas masks collect discs or granules of the spent cyclone, screw in the valves of the cylinders and screw safety caps onto them, collect the corpses of rodents and mechanical fishing gear. Spent disks and granules are burned in the firebox of the ship or on the territory of the decontamination department.

The vessel can be put into operation only after degassing of all ship premises has been completed. The determination of complete degassing is carried out by a chemist of the gasification squad in the ship's premises, previously closed for at least 11/2 - 2 hours so that the air temperature inside the premises is not lower than 20 ° C.

An approximate determination of the concentration of fumigants during the degassing period is carried out using the following methods. Methyl bromide is determined by a halogen indicator burner by changing the color of the flame (method sensitivity from 0.05 to 3.0 g/m 3 or mg/l); hydrocyanic acid - benzidine test (method sensitivity from 0.0011 to 0.05 g/m 3 or mg/l); sulfur dioxide - by the change in color of litmus paper (method sensitivity from 0.004 to 40.0 g/m 3 or mg/l). In those rooms where degassing is delayed, the doctor and assistant epidemiologist take measures to accelerate degassing in these compartments (heating, ventilation).

The delivery of the vessel is carried out by establishing the concentration of methyl bromide in the indoor air equal to 0.05 mg/l, hydrocyanic acid - 0.002 mg/l, sulfur dioxide - 0.01 mg/l. Particular attention should be paid to monitoring the content of residual amounts of fumigants in poorly ventilated rooms, containers (tanks) drinking water, fuel, etc.) without sufficient ventilation.

The head of the gassing squad, having received the test results, gives the captain or chief mate instructions for the ship's administration on the mandatory activities to be carried out by the ship's crew after gassing, and allows the crew to enter the ship.

The instructions indicate that the ship's crew must activate heating system and existing artificial ventilation. During the first 24 hours after delivery of the vessel, it is prohibited to close ventilation openings, portholes and holds. All bedding, carpets, upholstered furniture, take clothes to the upper deck for ventilation. Dirty laundry should be washed, clean laundry should be aired. Wash galley, dining and other utensils with hot water and soap. Also wash all areas of the vessel with hot water and soap. The indoor temperature must be at least 20°C. Crew members are allowed to sleep during the first 24 hours only with the windows open.

All work related to the use of such potent substances, such as hydrocyanic acid, sulfur dioxide and methyl bromide, must be strictly documented. The recording form must clearly, clearly and in detail reflect all aspects related to gas processing, indicating specific processing conditions.

In order to improve the use of methyl bromide, a technique for using this fumigant in a mixture with carbon dioxide was developed. This technique makes it possible to somewhat reduce the downtime of ships under gasification, reduce the consumption of methyl bromide and carry out treatment at a temperature inside the ship’s premises from 5°C. When these gases are used together, the diffusion properties of both components increase, sorption decreases and desorption of methyl bromide accelerates. Carbon dioxide at recommended consumption rates has a stimulating effect on the respiratory system of rodents and insects, causing deepening and increased respiratory movements. As a result, to ensure the complete death of biological objects, less consumption of the mixture components is required compared to the separate use of each of them. However, this method has not become widespread due to the complexity of the aeration technique.

Passenger gasification railway cars . Passenger soft and combined carriages, in cases of rodents and insects appearing in them, may be prescribed gas treatment, which is often carried out with hydrocyanic acid preparations.

Hydrocyanic acid can be used by decomposing cyanides (KCN, NaCN) with sulfuric acid (tub method); in the form of liquid hydrocyanic acid from cylinders (cyanization method in hangar conditions); when using cyclones B and D.

The tub method is very cumbersome, labor-intensive, requires increased dosages and exposures, increases degassing time, so at present it has lost its practical significance. The use of liquid hydrocyanic acid is more advanced, but requires special structures - sealed hangars. The use of cyclones, due to their simplicity and reliability, can be most widely used in the conditions of ordinary disinfection points located on special paths or in dead ends, at least 50 m away from residential and industrial premises, permanent places work on outdoors no closer than 25 m and 10 m from the main operating tracks of passing passenger trains. Areas where gasification of cars is carried out must be fenced, illuminated, and have a gate or barrier. Gas aeration technology for railway cars significantly simpler than technology gasification of sea vessels and fundamentally has few differences.

Airplane gassing is carried out mainly with methyl bromide and is technically the easiest task, due to both the relatively small volume of aircraft spaces and the availability of sealing.

Gasification of any object is carried out in strict accordance with current instructions on gas processing, which are approved by the relevant ministries.
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Chemicals. These include poisons for killing rodents, as well as preparations that protect various materials from being damaged by rodents or from animals entering premises (). Chemical poisons are used as food baits, in powder form for pollinating rodent burrows and trails, and also in a gaseous state for treating ships, elevators, etc.

Based on the nature of their action, poisons are divided into long-acting and fast-acting. The former include zoocoumarin, ratindane, pivalilyndandione, etc., the latter - ratsid, thiosemicarbazide, phosphide, barium sulfate, barium carbonate, arsenic compounds, fluoroacetamide, barium fluoroacetate, gaseous preparations, etc.

Zookoumarin- white or light gray powder with a characteristic odor. Insoluble in water. A special feature of the drug is its ability to cumulate (accumulate) in the animal’s body. Death of rodents occurs after repeated (over several days) administration of very small doses. The lethal dose for the gray rat is 0.25 mg daily for four days (total dose 1.0 mg), poisoned animals die on the 8-14th day. There is no alertness or addiction to zoocoumarin. Zookoumarin is commercially produced in the form of a working mixture (1 part of the drug per 199 parts of starch), from which poisoned baits are prepared (5% of the working mixture by weight of the finished bait); it is also used for pollinating burrows, rodent paths, and water. This drug is practically not dangerous to humans.

Ratindane- crystalline yellow powder. Insoluble in water. The lethal dose for the gray rat is 0.01 mg daily for 3-4 days. Rats die on the 6-8th day. It is produced by industry in the form of a working mixture (containing 0.5% active ingredient), tinted blue. It is used in the same way as zoocoumarin, but for food baits, 3% of this working mixture is taken to the weight of the bait. Ratindan is practically not dangerous for domestic animals and humans.

Pivalindandione(ratindan IV) - crystalline powder of yellow or golden color (pure preparation). Insoluble in water. Less toxic than zoocoumarin and ratindan: lethal dose for gray rat - 0.5 mg daily for 4 days. Rats die on the 8-16th day. Use in combination with zoocoumarin (1:1) significantly increases the effectiveness of the drugs. Like ratindane, pivalilyndandione is practically harmless to humans.

Krysid- an acute drug. Gray or brownish powder, insoluble in water. Highly toxic to gray rats and house mice (lethal dose 4.5-5 mg and 0.5-0.7 mg, respectively) and practically non-toxic to people and domestic animals. The death of rodents occurs within 24 hours. When poisoned with small doses of the drug, rodents develop resistance to it, which lasts 30-40 days, so repeated treatments with ratsid should be carried out at intervals of 4-6 weeks. The rat is used for preparing food baits (poison content 1%), pollinating water, burrows and rodent paths. Practically little dangerous to humans.

Thiosemicarbazide- white crystalline powder, soluble in hot (up to 10%) and cold (up to 2.5%) water. The lethal dose for the gray rat is 12 mg, for house mice - 1 mg. Due to the high content of the drug in food baits (5%), rodents eat them relatively poorly. Eating sublethal doses causes resistance to the drug in rats. Little dangerous for humans.

Zinc phosphide- dark gray, almost black powder, with the smell of garlic. Insoluble in water. The lethal dose for a gray rat is 15-30 mg, for a house mouse - 3-5 mg. The drug is dangerous for all animals and humans. Used in food baits (2-3%), for pollinating water (rarely). With prolonged use of the drug, rodents may develop wariness towards it.

Fluoroacetamide- white or grayish crystalline powder, highly soluble in water. The lethal dose for a gray rat is 7-10 mg, for a house mouse - 0.4 mg. Very dangerous for humans and pets. Used in food baits (with a poison content of 0.5-1%), for the production of liquid baits I (0.5% solutions).

Barium fluoroacetate- white crystalline powder, highly soluble in water. The lethal dose for a gray rat is 1 mg. Extremely dangerous for people and pets, the drug can only be used by specialist pest control specialists.

Sulfur dioxide- gaseous drug, 2.5 times heavier than air, well adsorbed various materials, and therefore its concentration in indoor air should be at least 2-3%. Dangerous for humans.

Preparations that protect premises and materials from rodents include the following repellents (repellent substances).

Albihtol- product of oil shale processing. Yellow oily liquid with a strong specific odor. The introduction of the drug into the rubber sheaths of the wires protects them from damage by rodents.

Shale oil- yellow oily liquid with a pungent odor. Used to protect polyvinyl chloride sheaths of wires.

Tsimat- zinc salt of dimethyldithiocarbamic acid, yellowish-white, finely ground powder, insoluble in water. Irritating to the mucous membranes of the oral cavity. Used to protect containers, fruit trees, houses from rodents, for which purpose the drug is added to the sealing materials - gypsum, plaster, clay. and the preparation in powder form is used for spraying and dusting surfaces and exits from burrows.

Various small insects, bugs and other rodents already cause enough hostility in most people, but when they appear in their home, it becomes a real disaster.

And this indignation is absolutely understandable, because small “reptiles,” as they are popularly called, are not only unpleasant for humans, but can also pose a serious danger to health and contribute to the development of various diseases not only in humans, but also in domestic animals.

If you do decide to try to deal with them yourself, then first it would be a good idea to find out what exactly you have to do. Perhaps you have decided that you need to disinfection of the apartment? Or maybe pest control? What if you still need deratization?

Since the procedures for exterminating them differ depending on the type of pest, it is better to understand this issue in advance. In this article we will talk about these concepts and the difference between them.

What is disinfection

Disinfection (or disinfection). Disinfection is generally understood as a set of measures aimed at destroying pathogens of various infectious diseases and toxins during external environment. Depending on the situation, there are several types of disinfection.

Types of disinfection

1. Preventive - such disinfection is mainly aimed at preventing the emergence of infectious diseases and should be carried out on a regular basis. Typically, this type of disinfection is carried out in crowded places, especially children, due to the high susceptibility of the young body to various viruses and harmful bacteria.
2. Current - disinfection of this type should be carried out in order to limit the spread of infection from an already existing source of disease. Its task is to prevent widespread spread.
3. Final - this type of disinfection implies the complete release of the disinfected premises from infectious agents and should be carried out after the source of the virus has been removed - after the object has recovered, been hospitalized or died.

Based on the above types, we can conclude that only preventive disinfection can be carried out on your own, and only an experienced disinfection specialist should deal with the current and final stages of cleaning the premises.

Disinfection methods

The process of cleaning a room from viruses can be carried out in different ways. In practice, three main disinfection methods are usually used.

1. The mechanical method is the simplest and most unreliable method of disinfection. With this approach, the number of bacteria and viruses only decreases, but is not completely reduced. This method includes washing, regular laundry, garbage removal and other preventive measures.
2. The physical method is of higher quality, in contrast to the mechanical one, and is usually aimed at the specific object of disinfection. These methods mean disinfection using high temperatures - steaming, boiling or heating; or under the influence of ultraviolet radiation - quartz treatment or the use of bactericidal lamps.
3. Chemical is the most reliable disinfection method. Its essence is to use chemical solutions, which have a detrimental effect on bacteria and their cells. Typically, chlorine-containing solutions are used for chemical disinfection, which contain: chloramine, bleaching powder, anolyte and other similar chemical composition substances.

Having dealt with disinfection, it is worth talking about what disinsection and deratization are.

What is pest control

Desinexation (extermination of insects). Disinsection is understood as one of the types of disinfection, which is the destruction of insects capable of carrying various infections, using special chemicals, by exposure to hot water with steam or using biological agents.

Disinsection also refers to the procedure for exterminating any insects whose proximity to humans is considered undesirable: flies, mosquitoes, cockroaches, ants, bed bugs, etc.

In simple terms, pest control is a set of measures aimed at getting rid of harmful or infected insects.

Types of pest control

1. Complete extermination - the use of special means that are lethal to the insects against which disinfestation is aimed.
2. Preventive disinfestation is the use of products that create unfavorable conditions for the development and spread of harmful insects in the disinfested area - cockroaches, bedbugs, lice, etc. Prevention consists of keeping the house clean, using protective nets on windows and doors, and preventing harmful insects from entering the room.

Also, in addition to the main types, several different disinfestation methods can be identified.

Deratization (extermination of rats)- a set of measures to exterminate various types of rodents (mice, rats, voles, etc.). The deratization procedure is quite dangerous and must be carried out by a specially trained person, subject to a set of safety measures. If handled improperly, you can not only get rid of rats, but also cause irreparable harm to human health and pets.

Main types of deratization:

1. Preventive deratization is a set of measures that are aimed at eliminating favorable conditions for the appearance of various types of rodents. This type of deratization includes, for example, blocking access of rodents to places suitable for making burrows or blocking access to food.
2. Exterminatory deratization is measures that are taken when rodents have already appeared in a room and aimed at their complete destruction and taking measures for this.

Deratization can be carried out different ways, usually use one of the three methods of deratization listed below.

Main methods of deratization:

1. The mechanical method is a method based on the use of various mousetraps, rat traps, traps and other traps.
2. Chemical method - a method in which different kinds baits poisoned with poisons, or so-called raticides.
3. Biological method is a method in which domestic animals that hunt them are used to kill rodents. This method is prohibited in enterprises.
4. Gas method - this method is mainly used in field conditions and in small confined spaces - ships, cars, airplanes, etc.

2.2.3. Chemical method

The chemical method is the main method of exterminating rodents in our country and abroad. Most rodenticides are intestinal poisons, because They are an integral part of poisonous food baits, poisonous coatings, or are used to pollinate burrows and water. When these substances enter the gastrointestinal tract in certain concentrations, they cause death only in rodents and at the same time are practically not dangerous to humans and domestic animals.

They are also used to control rats and mice. gaseous substances(sulfur dioxide, carbon dioxide, carbon monoxide, chlorine, chloropicrin, hydrogen cyanide, hydrogen phosphorous, ethylene oxide, methyl bromide). They belong to different classes and have different mechanisms of action. The advantage of their use is that the gases have a high penetrating ability and, at sufficient concentrations, cause 100% death of animals. However, there is no residual effect and the site can be repopulated with rodents immediately after the gas is removed. In addition, the toxicity of the gases is equally high for other warm-blooded animals, including humans, resulting in a dramatic increase in the cost of ensuring the safety of non-target species. These disadvantages significantly reduce the possibilities of using gases. Currently, aeration is rarely used and only for the treatment of special objects - ships, wagons, elevators, and less often - refrigerators.

All rodenticides are combined into two large groups, each of which is characterized by the specific action of its constituent drugs on the animal’s body: these are fast (acute) and delayed (cumulative) action drugs.

Poisons acute action- substances belonging to various groups of organic and inorganic compounds, characterized by a diverse mechanism of action. Typically, the effect of these poisons is manifested in inhibition of the process of digestion of food in the stomach for up to two days or more, i.e. until the animal dies or recovers. The result of exposure depends on the amount of poison absorbed by the animal.

For a long period of time, effective acute poisons in baits (90% or more) were sodium fluoroacetate, thiosemicarbazide, glyfluorine, phosphorus, thallium sulfate, zinc phosphide, ratsid, etc. They represented the most promising group of drugs. Less effective (50 - 80%) were preparations of arsenic, barium carbonate and red sea onion; strychnine, which was very poorly eaten, gave only 10% effectiveness. Subsequently, all of the listed poisons were removed as the most dangerous to human health and target animals, except for zinc phosphide and ratsid. Currently, these drugs have been joined by a new drug - aminostigmine.

Quick-acting poisons after rodents eat poisoned bait cause their death within 24 hours - 3 days. In most cases, symptoms of poisoning by these poisons begin to appear from the very first hour after entering the body. However, the rapid development of the poisoning process also makes rodents wary of bait containing poison. Subsequently, the rodents begin to refuse the bait. In order to avoid this, you should limit the use of acute poisons to 1-2 times a year.

Of the group of acute poisons, the most widespread is zinc phosphide - substance according to appearance It is a dark gray powder with a garlic odor. The toxicity of zinc phosphide is associated with the formation of phosphine in the body, as a result of its decomposition in the acidic environment of gastric juice, which, when entering the stomach of a rodent, reacts with hydrochloric acid. Phosphine penetrates the blood, brain and acts on the respiratory center, causing the death of the rodent.

Zinc phosphide decomposes in an acidic environment, so it is not recommended for use with rye bread, sour dough and other quickly souring products. Poisoned zinc phosphide baits should not be used as long-term points of poisoning (LPP), since zinc phosphide quickly interacts with hydrogen ions in the air and its activity decreases. Zinc phosphide is most effective in the fight against house mice.

Table 4

Toxicity of zinc phosphide to various animals and humans when ingested.

Another acute poison is ratsid, which is effective for all types of rodents. Due to the clearly expressed electoral action It was from gray rats that it got its name. Available in powder (98%) and 10% gel form.

This drug is a dark gray, crystalline, easily dusty powder with a molecular weight of 202.3, poorly soluble in water (0.6 l). Decomposes when exposed to alkalis. This drug was first obtained in the USA by Richter in 1944, and based on published data, it was synthesized in Russia in 1946.

The most important advantage of ratsid is the speed of its action - rats, as a rule, die within the first two days after taking the bait and its selectivity - increased toxicity towards the gray rat.

The disadvantage of ratsid in powder form is its high volatility.

Table 5.

Toxicity of "Rat" for various animals.

Rasid-gel is a preparation of semi-liquid consistency, the content of the active substance ("pure ratsid") in the gel is reduced by an order of magnitude, i.e. to 10%, which makes it correspondingly less dangerous and much more convenient to handle. There is no spraying of powdered poison and involuntary pollution of the environment.The gel has an unattractive color and can be easily removed if it gets on any surface.

The gel form of the drug “Krysid” allows you to easily dose it, transport it in a tight container and avoid accidental losses. The optimal dose of DV is a concentration of 1% (10% of the gel in the bait), at which 70% of the animals die within two days.

Animals that die from rats first stop breathing and then their heart. At autopsy, inflammatory changes are observed in the lungs.

Aminostigmine/ N, N - dimethyl - (2- N, N - dimethylaminomethylpyridyl-3) carbamate dichloride / is a new highly effective means of combating mouse-like rodents.

It is used in practice in the form of a ready-made bait (trade name AMUS), which is a food base (confectionery waste), poison (0.4%), attractant and dye.

LD50 of AMUS bait for mice is 120 mg/kg live weight, gray rats - 300-400 mg/kg) and black rats 260 mg/kg. House mice are the most sensitive to poison. In its action, aminostigmine (AMUS) is a reversible cholinesterase inhibitor. According to the degree of impact on the human body, AMUS belongs to hazard class 4. The maximum therapeutic daily dose is 20 mg, which is equivalent to 4000 mg of AMUS bait, and the lethal dose for humans is 100 times higher. As a result of the action of aminostigmine, severe toxicosis appears (immobilization, muscle fibrillation, tremors, etc.). Atropine serves as an antidote.

To the poisons cumulative action These include substances that can accumulate in small concentrations in the animal’s body and subsequently cause its death. These include: blood anticoagulants, vitamins D, chemosterilants and substances that reduce metabolism.

In contrast to acute poisons (zinc phosphide, ratsid), when small amounts of such poisons enter the rodent’s body once, the symptoms of poisoning practically do not appear. Rodents do not associate painful manifestations with the use of bait; they repeatedly eat it in almost the same quantities as products without poison. This explains the lack of alertness to these drugs. Blood anticoagulants are the most common in deratization.

Blood anticoagulants- these are substances of the oxycoumarin and indadionic series. All of them are very similar in structure, mechanism of action and deratization effect. Their discovery provided a fundamental turn in the war against rodents. The history of their appearance begins from the moment when research was carried out aimed at elucidating the causes of death of dairy cattle from internal hemorrhages in North America. It has been found that feeding moldy legume hay often leads to this. It was later determined that in such hay, under the influence of certain mold-causing fungi, a chemical substance, coumarin, is converted into a drug that counteracts blood clotting. As a result of its identification, synthesis and study, medicine received a remedy for the treatment of thrombosis, and then for the fight against rodents .

The mechanism of action of anticoagulants is to stop the normal formation of blood clotting factors - coagulation, which is based on a complex system of various metabolic processes. Prothrombin, the inactive form of thrombin proteinase, is one of the important initiators of blood clotting. It is synthesized in the liver from various precursors. This synthesis requires vitamin K1, which acts as a coenzyme for carboxylase.

Anticoagulants have a chemical structure similar to that of vitamin K1 and act as antagonists to the latter. There is a competitive inhibition of the activity of vitamin K1. As a result, prothrombin formation does not occur, and the blood loses its ability to clot. Most rats or mice poisoned with an anticoagulant die from internal bleeding, and some also from bleeding wounds (rats quite often become involved in territorial fighting, during which they are injured).

The effect of anticoagulants occurs with some time delay, and rodents die, as a rule, 3-8 days after they first eat the bait. Moreover, the speed of action of anticoagulants is very different and varies from 2-3 days to 12-15 days. It depends on the condition of the animal, the amount and toxicity of the absorbed anticoagulant.

Animals exhibit increased lethargy and die in the absence of any signs of pain. Due to the delayed onset of this action, rats are unable to make a connection between the signs of poisoning and the bait. The phenomenon of fear of bait, observed with fast-acting (acute) poisons, is absent after the use of an anticoagulant.

One of the special properties of the anticoagulant is that its effectiveness increases with repeated consumption of the bait. Within 5 days of eating bait with poison, its average lethal dose decreases from 16.5 mg/kg (acute) to 0.3 mg/kg. Thus, the method of repeated dosing potentiates the activity of the drug. Because rats return to feeding areas where there is good food containing bait, the anticoagulant becomes more and more potent each time the rats eat the bait.

The multiple dose effect increases the potency of rodenticides while at the same time reducing the risk of accidental poisoning of non-target species and wildlife. Since vitamin K1 acts as an antagonist to the anticoagulant, any accidental poisoning with the latter can be cured by administering vitamin K1 intravenously or intramuscularly. Vitamin K1 is an antidote to anticoagulants.

Along with this positive aspect, anticoagulants of the 1st and 2nd generations discovered a very unpleasant property - the ability to quite quickly form clearly expressed resistance to poisons in rodents. Since anticoagulants are the brainchild of Western technologies, they encountered this phenomenon primarily in the West. The specialized literature of the 70-80s is replete with reports of the presence of resistant populations of rodents in the USA, Great Britain, Scotland and other countries. The presence of resistance can be detected using the developed method (Appendix 7).

Moreover, it turns out that rodents sometimes develop resistance to several anticoagulants. As a result, the fight against this phenomenon becomes significantly more complicated and the need for repeated treatments arises. They are carried out either with a more powerful anticoagulant (for example, 2nd generation) or with acute poisons (zinc phosphide). The use of the latter usually gives the best results.

Poisons of cumulative action include chemosterilants, which, according to many researchers, have great promise in the fight against rodents, since they cause permanent or temporary sterility in animals of one or both sexes. Chemosterilants include: steroidal compounds (estrogen, mestranol) and non-steroidal compounds (ethylenimine, methanesulfate, colchicine, cyclophosphamide, thiophosphamide, and many others).

Unlike acute poisons, which cause a strong but short-term effect, chemosterilants do not initially bring visible positive results, but subsequently have a long-term sterilizing effect on the population structure, inhibiting the generative system of rodents. For example, the main drug, an acute rodenticide, zinc phosphide, provides the initial effect (death of 80-90% of animals in the population), and the restoration of their numbers to the original level occurs 6-8 months after treatment. The initial effect does not spread over time, and the number decreases only by the number of animals that directly died from the poison. In addition, the reduction in the number of rodents leads to the migration of other animals to the liberated areas and their increased reproduction.

When using a chemosterilant (for example, indomethacin) in baits, the effect occurred after 5-8 months and had a long-term effect (3-4 years), due to a decrease in fertility.

In the last decade, preparations based on vitamins of group D: cholecalciferol, oxycalciferol. Their mechanism of action, unlike anticoagulants, is based on a violation of calcium metabolism: the transfer of calcium reserves from bones to blood plasma. Its accumulation blocks blood vessels in the brain and heart. Hypercalcemia causes cardiac-type death 2-4 days after reaching a lethal dose.

The advantage of preparations based on vitamins of this group is the close values ​​of acute and cumulative doses, because accumulation occurs quite quickly (1-4 days). Once hypercalcemia is achieved, rodents stop eating, so some researchers classify these substances as acute poisons. However, it should be taken into account that vitamin-based baits are not very stable in environment. This is their advantage, since they do not pollute it, but also a disadvantage, because... The shelf life is short compared to other poisons.

Among other cumulative drugs that differ in the mechanism of action from anticoagulants, drugs based on L - and B - chloralose should be noted. The effect of these substances on warm-blooded animals is expressed in the inhibition of metabolic processes, a decrease in pressure, respiratory rate and body temperature, which, with an appropriate dosage, causes the death of the animal. It should be noted that chloralose-based preparations work best at temperatures below 15 degrees C.