How to remove dust from the body. Bedbug dusts: review of drugs and reviews of their use. Step-by-step algorithm of actions

All remedies are good against bedbugs. This truism is a strict statement for those who have already tried many drugs and methods in an attempt to get rid of these insects. Considering the peculiarities of the life activity of bedbugs and their reproduction, removing them from a living space is not so easy.

Ordinary dust is a chemical insecticide that residents of the former Soviet Union. At one time, this substance was used to poison everything from fleas on domestic animals to treating crops, killing mosquitoes, and treating head and pubic lice. Today we hear little about dust; the shelves of hardware stores are filled with all sorts of chemicals, mainly made in China with a questionable performance rating.

We have set ourselves the goal of reminding the residents of our country what dust is, we will talk about its main historical merits, and also look into its chemical formula to understand how effective the product is against house bugs. And of course, nothing will support our theoretical research as much as reviews from people who have used dust in practice against bedbugs.

What is dust?

Dust is an insecticide of chemical origin, more accurately called DDT. This product began to be called dust due to its powder form, as is known in English language“dust” is translated as “dust, powder.” Dust is a colorless, crystalline, tasteless and almost odorless organochlorine agent known for its high insecticidal properties. DDT is produced only in the form of dry powder additives, which help protect the active working substance from decay. It is these additives that give the dust its grayish-blue color and specific smell.

“We bought the dust, hoping for its effectiveness, and really regretted it. The smell is unbearable, this powder, which had to be poured everywhere, is annoying. It’s scary to get poisoned, not to mention the children and dog who had to be sent to their grandmother. Yes, there are fewer bedbugs, but they haven’t all disappeared, because it’s impossible to cover everything in the world. We will now buy something that can be sprayed and is not so poisonous for people.” Anna.

Today, DDT is an ingredient in many commercial insecticides. Due to its hydrophilic molecule, DDT can be used in virtually all forms - emulsifiable concentrates, water-soluble powders, granules, aerosols, fumigants, evaporators and aqueous solutions.

DDT was first synthesized in 1874, but the insecticidal effects of the drug were discovered much later by the Swiss chemist Paul Hermann Müller in 1939. Doust received widespread publicity for helping control the spread of malaria and typhoid among civilians and military personnel in the second half of World War II. DDT does not have disinfectant properties, but it can suppress the huge prevalence of body lice, head lice and mosquitoes, which are known to transmit typhus and malaria, respectively.

After the war, DDT became available for use as an agricultural insecticide, and its production and use were increased accordingly. Müller was awarded the Nobel Prize in Physiology or Medicine "for his discovery of the high effectiveness of DDT as a contact poison against certain arthropods" in 1948.

However, the ascent to Olympus was short-lived. In 1962, the book “Silent Spring” by American biologist Rachel Carson, which was published, turned international attitudes towards DDT upside down. This catalog was made public environmental consequences indiscriminate spraying of DDT in the United States and questioned the logic of releasing large quantities of potentially hazardous chemicals into the environment without sufficient understanding of their environmental or human health impacts.

In addition, the author argued that DDT and other pesticides can cause cancer and that their agricultural use poses a threat to wildlife, especially birds. The book's publication was a landmark event for the environmental movement, leading to great public outcry that ultimately led to the ban on agricultural use of DDT in the United States in 1972.

Worldwide bans were subsequently formalized under the auspices of the Stockholm Convention on Persistent Organic Pollutants, but the limited use of dust to control insect vectors continues to this day and remains controversial. DDT remains effective means in reducing human mortality from malaria, which itself considers a higher priority than environmental protection and concerns for the health of birds.

In Russia today, dust continues to be actively used against body and household insects, but its use in the agricultural sector is very limited. Here, DDT is replaced with pyrethroids - insecticides of plant origin, which are considered more friendly to warm-blooded creatures.

Impact on human health

Of course, it was not in vain that noise was raised against the active use of DDT in any of its forms, including in the form of powder - dust. In addition to the harmful effects on the environment, DDT interferes with the functionality of the human endocrine system, but as for the carcinogenic effect, although much was said and written about this at one time, no detailed studies have been carried out.

DDT is classified as a "moderately toxic" substance by programs in different countries, including Russia. It is considered “moderately dangerous” according to the World Health Organization (WHO) classification. This means that in pure form DDT cannot be purchased in regular hardware stores today. The right to use it is available to persons who have completed training and internship, as well as those who are employees of organizations engaged in professional destruction insects

“We noticed one bug crawling out from under the baseboard. We went to the neighbors and it turned out that they were poisoning. We bought dust and filled all the cracks. The smell was terribly unpleasant, in the first days we could not sleep at home, then it dissipated a little and we ventilated it constantly. But we must pay tribute - the bedbugs did not move to us, we did not notice any more of these pests, and none of the family had any bites. So in some cases it can be used.” Ildar

Among other things, DDT is characterized by the likelihood of chronic poisoning. This effect can be achieved with a long-term and regular toxic effect of DDT on the human body. DDT, like other chlorines organic compounds, have xenoestrogenic activity, due to the fact that the molecules of dust and female sex hormones are chemically quite similar. As a result, DDT is able to cause appropriate hormonal reactions in animals and humans. In general, such a toxic effect of DDT is expressed in the following violations:

• premature birth;
• endocrine reproductive system disrupting properties;
• decreased sperm quality;
• pathologies of menstruation;
• change in the duration and quality of lactation.

Using dust for bedbugs

In addition to all of the above, it is worth noting that modern dust, in the general understanding, may not contain pure DDT in its composition due to its limited use sanitary standards. And in those packages that are sold, the so-called “Chinese bedbug dust”, there is everything you want, but only DDT. Therefore, it is better to refuse such an offer from Chinese underground manufacturers immediately, otherwise you can make it so that there will be no one left in the living space except bedbugs and cockroaches.

Therefore, when purchasing dust, it is better to trust to a domestic manufacturer, and it is better to directly purchase goods from organizations that not only distribute insecticides, but also themselves engage in baiting domestic insects. Here there is the highest probability of acquiring a truly high-quality drug.

It is permissible to use the dust in the form of an aqueous solution, but before pouring the powder into water, you should read the instructions - the mixture may contain substances that are insoluble in water. The best option for using dust against bedbugs is to use it in the form of a dry powder. For those who decide to treat their bedroom with dust themselves, you should know the following.

Dust is a dry powder and the less moisture it contains, the more effective and greater its insecticidal properties. Therefore, you need to initially treat dry surfaces, and protect your respiratory organs with a respirator. Inhalation of dry chemical particles necessarily stimulates their absorption on the mucous membranes and can provoke irritation and even general poisoning of the body.

Before processing, you need to take out all things that can be removed and lifted in sealed plastic bags. This category includes: bed linen, Stuffed Toys, electronics, contents of drawers, cabinets and so on. It must be remembered that these things may contain adult bedbugs and their eggs. The bags will prevent them from getting out as they move around the apartment and infecting other rooms. All items must be additionally treated with temperature or chemicals that allow the processing of fabrics and plastic.

At the time of treatment, there should be no pets, birds or aquarium fish in the room. For the last two categories, it will be enough to inhale a few particles of dry dust for irreversible changes to begin in their body.

As already noted, funds are needed personal protection- gloves, goggles, mask or respirator. Clothing should not allow dust to penetrate bare areas of the skin.

Before treatment, wet cleaning of all surfaces that need to be sprinkled with dust is recommended, this will increase the insecticidal effect.

After treatment, pets should not be allowed into the room.

Precautionary measures

True dust has specific smell, which may disrupt night sleep, and the smallest particles of chemistry can cause allergic reaction. Therefore, if there is pain in the eyes, watery eyes, sneezing, headache, nausea and other signs of disorder general condition, it is necessary to interrupt contact with dust as soon as possible and seek medical help.

Efficiency of dust against bedbugs

In general, DDT is very effective against any insect. It is not for nothing that the Nobel Prize was awarded for this discovery. However, the reviews that can be found on the Internet are contradictory, which we attribute to different chemical composition products distributed under the Dust trademark, as well as the frivolity of manufacturers.

//www.youtube.com/watch?v=2CcHlvQdWCg

1. Dust repellent for bedbugs.
2. What does it consist of.
3. How to use this drug.
4. What harm does dust cause to people?

Dust - description of the drug

Dust is an insecticidal drug that is effective in the fight against bedbugs, cockroaches, flies, ants and fleas. On average, the packaging of this powder is designed for 10 m2. Due to its physiological properties, the dust is resistant to temperature changes and works great in dusty places. After cleaning, microparticles of powder remain on the treated surfaces, which continue to act for several months.

The composition of this drug may vary depending on the manufacturer's brand. To attract buyers and increase the price, flavors and dyes are added to the powder, but this does not affect the quality of the dust. The base of pure dust powder contains:

• Cypermethrin (colorless insecticide, due to its viscosity helps to increase the duration of the drug).
• Malathion (a poisonous substance that is used against any insects).
• Synergist piperonyl butoxide (helps accelerate the penetration of toxic substances through the cuticles of arthropods).
• Solvent.
• Talc (most of the powder, filler).
• Lubricant.

The main properties of this drug

In the fight against bedbugs, you will need more of the drug than in the fight against other insects. The structure of their proboscis is designed to feed on blood; it is difficult for them to swallow powder. Therefore, the composition of the dust is aimed at destroying insects upon tactile contact. The toxicity of this substance is not high and allows a person to stay indoors throughout the entire period of pest control.

Popular dust-based powders

On the shelves of non-food stores we see huge assortment various drugs for bedbugs. Here is a list of the most effective dust powders:

• Klopoveron. The drug was created for use by specialists in large areas of infection, so it rarely appears on sale. It is an order of magnitude more expensive than other insect control products.
• Dust " Clean house" This is very reliable means used in domestic conditions. It has moderate toxicity, so you should strictly follow the instructions for use.
• Phenaxin is odorless and provides good results.
• Fas-double – serves as an analogue to Phenaxin.
• Riapan. Active substance This powder is permethrin. The effect of the drug lasts for 3-4 days.
• Dust "Tornado". One package is enough for 70m2, approximate cost drug from 20 rubles.
• Neopine. A type of powder that can be diluted with water and treated in hard-to-reach areas.

How to use?

It’s quite easy to poison bedbugs yourself with dust. When processing an apartment, you must follow the following rules:

• Preparing for work. We remove food, personal hygiene products, dishes, animals and other residents from the premises, and open all windows.
• Overalls. Wear clothing that is as closed as possible, gloves and goggles. Be sure to use a respirator to avoid inhaling pollen powder.
• To apply the powder, use a washcloth or wide brush.
• Spread it in a thin layer over inner surface beds, carpets, baseboards and pest habitats.
• We try to carefully pour the powder into places where there are cracks.
• If you need a liquid consistency of the dust, but you don’t know how to dilute it, pay attention to the instructions written on the package.
• If pollen gets into your eyes, rinse thoroughly with running water.
• Having finished processing the room, we take off our clothes and send them to the wash. We take a shower and go for a walk for 3-4 hours.
• After the specified time has passed, we begin cleaning the room. Using a vacuum cleaner, remove the remaining powder from upholstered furniture, wash the remaining surfaces with soda solution.

Harm to humans

The question often arises of how toxic anti-bug products are. Scientists say DDT has harmful effects on the environment and interferes with the human endocrine system. However, the health organization considers this drug moderately toxic. There is a risk of chronic poisoning if it is used daily for a long time. With long-term use of out dust at home, there is a risk of disruption of the following body functions:

• The endocrine reproductive system is destroyed.
• Sperm quality decreases.
• There is a risk of premature birth.
• The menstrual cycle is disrupted.
• The quality of lactation deteriorates.

Advantages and disadvantages of this drug

The product is very effective against insects. However, compared to other insecticides, the powder is not very convenient to use. Read more about the advantages of dust products:

• Most powders do not need to be diluted in water. However, there is a dust that is used in liquid form; how to dilute it is written in the instructions on the package.
• Low price.
• One package is enough for large area defeats.
• The dust affects more than 20 species of insects. However, bedbugs are one of the few who get used to the toxic properties of dust.
• It is less toxic to humans.

What are the disadvantages of the powder:

• Inconvenient to use. The powder must be scattered and then rubbed onto the surface.
• Low concentration of toxic substances.
• Characteristic smell.
• Bedbugs develop immunity to certain powders.

It is quite possible to destroy bedbugs in the house with the help of dust

Dust - basic properties

The name dust combines many products with similar properties. Release form is usually loose powder white, which can be either in pure form or with various additives. All dusts are quite powerful insecticides, many of which are based on boric acid, others on other auxiliary substances with similar effects. Depending on the manufacturer, this product may have different composition, color and smell due to the inclusion of certain additional ingredients.

However, in any embodiment, the dust will have the ability to exhibit its basic properties at any temperature. The only thing that can prevent it from maintaining its poisonous effect is high humidity during storage.

How does dust differ from other pesticides? First of all, the main working component is called pineronyl butoxide. It is this that provides the active components with a prolonged effect, that is, thanks to this substance, just one treatment of the contaminated room will provide a long-lasting poisonous effect.

However, it should be borne in mind that to kill bedbugs you will need a slightly larger amount of dust than, say, when baiting cockroaches. Both the first and second are very tenacious, but cockroaches are still inferior to bedbugs. But at the same time, dust, among other insecticides, shows best results it is in the fight against bedbugs that this is the most profitable option baiting, since the powder particles will retain their toxic activity for a long time and gradually destroy all individuals of the colony over several weeks.

Criterias of choice

On a note! Contact insecticides are fundamentally different in their principle of action from intestinal insecticides. Such substances do not necessarily enter the body through the esophagus. In order for them to begin their work, they only need to get on the chitinous cover. That is, if a bug runs through the scattered dust, it will probably smear its paws in it. And this is quite enough.

Effective dusts against bedbugs

Despite the fact that on the market household chemicals Today there are a huge number of dusts, but relatively few are truly effective. And they are often used not only by ordinary people, but also by specialists from pest control services and SES. Let's look at the most active dusts that have been tested for suitability and have shown excellent results in practice.

On a note! Independent use"Klopoveron" is inappropriate in most cases. It is much easier and cheaper to turn to professional pest control services for help!

Terms of use

Dust must be used throughout the entire room. Treatment of individual zones will not bring a positive result. The powder is scattered in an even layer on all surfaces and left for a while.

Important! Not every dust can be diluted with water! You will always find information about the application technique in the instructions!

Let's look at the main processing steps in more detail.

• First you need to properly prepare the room. We remove all people and pets from the room. We inspect and clean small items. We put food products in sealed containers or take them out of the room. We remove covers and bed linen from sofas, armchairs and beds and, if possible, wash them automatically at the highest possible temperature.
• We move all the furniture away from the walls, if possible we disassemble or unfold it so that all parts of cabinets, beds, sofas, etc. were available during processing.
• It is advisable for the handler to use personal protective equipment: gloves, goggles and a cotton-gauze bandage. It is better to choose clothes from dense material - this way you will provide protection to the skin.
  

  On a note! Modern dusts are not particularly toxic to humans, but inhaling their small particles is highly undesirable!

• Now take a wide brush and use it to apply dust to all surfaces. It is better to simply scatter the product near the baseboards and joints of facing panels. We carefully process the wallpaper joints, back and internal walls pieces of furniture. We apply dust on the window sills, door frame and around ventilation grilles. We treat the upholstery of upholstered furniture as well as possible, both the internal parts and all seams.
• After surfaces have been properly treated, leave the room and wash your hands and face thoroughly. We remove protective clothing and wash it. After a few hours (4-5), we ventilate the room and carry out wet cleaning using a soap solution with the addition of soda. Hard-to-reach places should not be washed - the dust should remain there. long time– 1-2 months.

No matter how carefully you apply the dust, you will not be able to get rid of bedbug eggs. For this reason, repeated treatment is necessary, due to which the young hatched individuals will be destroyed.

Water-soluble dusts against bedbugs are more convenient to use. They are easier to apply to various surfaces, and they stick to them much better.

Almost all modern powder insecticides have a neutral odor and evaporate extremely little. Therefore, without much concern, they can be left on pieces of furniture for several days and their presence will be quite safe. However, if you use old formulations (based on DDT), remember that such dusts can accumulate in the body. Therefore, after treatment they must be washed off thoroughly.

On a note! For this reason, today DDT is not recommended for use in everyday life and agriculture! It is much safer to use modern insecticides - they are not inferior in effectiveness to their predecessor and at the same time are not capable of causing much harm to the health of humans and domestic animals!

During processing, it is extremely important to ensure that there are no children or pets in the room. In no large quantities Dusts are not dangerous, but it is better for children and animals not to come into contact with them. In addition, the condition of other residents should be taken into account - if someone has allergies or suffers from bronchial asthma, all prescribed safety measures must be followed. It is advisable to remove persons with high sensitivity to the components of the drug from the premises during treatment.

Don't expect instant action from the dust. A positive result will be observed only a few days after treatment. In the first few days, the activity of bedbugs will decrease, but only slightly. Therefore, first of all, you must initially decide whether it is suitable for you this remedy or a faster result is needed.

So, having examined the properties and principle of operation of dust from bedbugs, we can highlight its main pros and cons. Positive sides– it is safe for people and warm-blooded animals, effective and prolonged action. Among the negative characteristics are the low concentration of the active substance and, compared to other insecticides, dusts are not very convenient to use.

Dichlorodiphenyltrichloroethane, better known by the abbreviation DDT, was synthesized back in 1874, but it was only in 1937 that this compound was discovered to be highly toxic to insects.

The first case wide application new insecticide was the mass pollination of the Pacific Islands with DDT dust, undertaken American army before the liberation of the islands from the Japanese in 1942. This protected the paratroopers from malaria, dengue fever and other tropical diseases carried by insects. Winter 1944 American soldiers in Naples they sprayed with dust to destroy lice.

After World War II, a new insecticide began to be widely used to kill pests. Agriculture, but after some time it turned out that this substance decomposes in nature extremely slowly, is transmitted through the food chain to other organisms, accumulates in them and slowly poisons them. In addition, DDT-resistant insect lines have emerged that can withstand even tenfold doses of the drug. Therefore, the use of DDT has been banned in most countries for almost thirty years (Sweden was the first to ban this insecticide in 1969). True, the World Health Organization has not banned DDT, but has not financed its purchases by developing countries for a long time. The World Bank doesn't even give loans to countries that still use this insecticide.

However, it is now discovered that there is no better way to control malarial mosquitoes than DDT. When South Africa, far behind other countries, banned the insecticide in 1996, malaria cases rose more than sixfold, and five years later it was allowed again. Just don’t spray it in tons from airplanes flying over cities, ponds, swamps and farmland. Experts now believe that careful use inside homes is quite acceptable. According to the WHO, two grams of DDT per square meter adobe walls reduce the likelihood of malaria infecting the residents of the house by 90%. Spraying needs to be repeated only once a year. That's why the World Health Organization has endorsed the use of DDT for indoor spraying, saying it is not only the best weapon for fighting malaria mosquitoes, but also the cheapest and most effective of insecticides. If used correctly, DDT poses no threat to nature or humans.

In addition, recently we had to call into question the data on the accumulation of DDT and toxic products of its breakdown in wildlife.

About twenty years ago, ecologists monitoring the maintenance toxic substances in the fat of marine mammals, unknown organic compounds with chlorine atoms in the molecule began to be detected in fat samples. Their structure resembled DDT, and it was concluded that the drug and its decomposition products were carried by rivers into the ocean and accumulated there in mammals.

And recently, in a bottle of whale oil, preserved in the last whaler sailing ship that was permanently laid up off the coast of Connecticut (USA), the same compounds were found - as many as 11 of their varieties. Since the fat sample dates back to 1921, when DDT was not produced or used, one can only conclude that these compounds are synthesized somewhere in the ocean. Where exactly is not yet clear, it is only known that something like DDT is produced by symbiotic bacteria that live in sea sponges and, apparently, thereby protect their hosts from being eaten.

And many other countries. However, recently a number of reports have appeared about the significantly exaggerated harm of DDT. There is an assumption that the main harm to mammals and birds is caused not by DDT itself, but by impurities (mainly dioxins) that arise during its industrial production. WHO officially recommends the use of DDT for the prevention of malaria.

History of creation, receipt, application

DDT (C 14 H 9 Cl 5) is classic example insecticide. DDT is white in form crystalline substance, tasteless and almost odorless. First synthesized in 1873 by the Austrian chemist Othmar Zeidler, it was not used for a long time until the Swiss chemist Paul Müller discovered its insecticidal properties in 1939, for which he received the Nobel Prize in Medicine. in 1948 as "For the discovery of the high effectiveness of DDT as a contact poison."

DDT is an extremely effective and very easy to produce insecticide. It is prepared by condensing chlorobenzene (C 6 H 5 Cl) with chloral (Cl 3 CCHO) in concentrated sulfuric acid (H 2 SO 4). DDT is a topical insecticide, that is, it causes death on external contact by affecting nervous system insect. The degree of its toxicity can be judged by the fact that fly larvae die when less than one millionth of a milligram comes into contact with the surface of their body. Thus, it can be argued that DDT is highly toxic to insects, while in appropriate concentrations it is harmless to warm-blooded animals. However, if these levels are exceeded, it also has a toxic effect. In particular, in a person into whose body DDT can penetrate through the respiratory system, skin, and gastrointestinal tract, it causes poisoning, the symptoms of which are general weakness, dizziness, nausea, irritation of the mucous membranes of the eyes and respiratory tract. DDT poisoning is especially dangerous when processing premises and seeding material. In addition, exposure to large doses can be fatal. Data obtained as a result of clinical studies make it possible to determine the toxicity of DDT for humans as follows: see Table No. 1. Due to the danger of DDT poisoning, all types of work with it are carried out with the mandatory use of personal protective equipment (working clothing, safety shoes, respirator, gas mask, safety glasses, etc.).

The benefits and harms of DDT

Except household use As a means of controlling pests such as flies, cockroaches and moths, as well as being beneficial to agriculture as a means of controlling pests such as the Colorado potato beetle and aphids, DDT has a number of generally recognized "heroic" achievements on a global scale, among them the most the following are significant:

• In January 1944, a typhus epidemic in Naples was prevented using DDT. This is the first winter epidemic of lice-borne typhus that has been stopped.
• In India, thanks to DDT, not a single person died from malaria in 1965, while 3 million people died in India. The US National Academy of Sciences estimates that DDT saved 500 million lives from malaria during its use until 1970.
• In Greece in 1938 there were a million people with malaria, but in 1959 there were only 1,200 people.
• In the Italian province of Latia in 1945, the monthly mortality rate from malaria was 65-70 people, and after DDT was used, it dropped to 1-2 people in 1946.
• The use of DDT largely rid India of visceral leishmaniasis (carried by mosquitoes) in the 1950s and 1960s.

Thus, the world quickly gained positive experience with the use of DDT. This experience led to a rapid increase in the production and use of DDT. The increase in the production and use of DDT was not the only consequence of the “positive experience”. It was also the reason for the formation in people's minds of erroneous ideas about the non-toxicity of DDT, which in turn led to the cultivation of carelessness in the use of DDT and a disregard for safety standards. DDT was used anywhere and everywhere without complying with the requirements established by sanitary and epidemiological standards. The current situation could not but lead to negative consequences. For example,

• V kindergarten, in Iran, when preparing porridge, the jars were mixed up and the corresponding amount of DDT dust was poured into the cauldron instead of powdered milk. Several dozen died from poisoning;
• In the early 1950s, the Colombian government forcibly sprayed DDT on peasants visiting the Ministry of Agriculture to combat lice.

The peak of this euphoria came in 1962, when 80 million kilograms of DDT were used for their intended purpose and 82 million kilograms were produced. After which the production and use of DDT began to fall. The reason for this was the worldwide debate about the dangers of DDT, which was caused by the book of the American scientist Rachel Carson “Silent Spring”, which means “Silent Spring” or “Silent Spring”, in in which Carson argued that the use of DDT had a detrimental effect on reproductive function in birds. Carson's book caused a wide resonance in the United States. Carson was supported by various environmental organizations, such as the Environmental Defense Fund, National Federation Wildlife Federation (National Wildlife Federation). The producers of DDT and the government administration supporting them, represented by the Environmental Protection Agency, sided with Carson's opponents. The debate about the dangers of DDT soon grew from national to international. However, Carson's conclusions about the dangers of DDT were not based on any scientific basis.

In his book, Carson draws on the research of James DeWitt, summarized in his articles “Effects of Chlorinated Hydrocarbon Insecticides upon Quail and Pheasants” and “Chronic Toxicity to Quail and Pheasants of Certain Chlorinated Insecticides.” insecticides" (“Chronic Toxicity to Quail and Pheasants of Some Chlorinated Insecticides”). Carson praises DeWitt's research, calling his experiments on quail and pheasants classic, but she misrepresents the data DeWitt obtained from his research. Thus, referring to DeWitt, Carson writes that “Dr. DeWitt's experiments (on quail and pheasants) established the fact that exposure to DDT, without causing any noticeable harm to birds, can seriously affect reproduction. Quails whose diets were supplemented with DDT survived throughout the breeding season and even produced a normal number of eggs with live embryos. But few chicks hatched from these eggs.” However, Carson leaves out the numbers in his book. The fact is that from quail eggs that ate food containing DDT in large quantities, namely 200 ppm (that is, 0.02%; for example, at that time the maximum permissible concentration of DDT for eggs established in the USSR was 0.1 ppm ), only 80% of the chicks hatched, but 83.9% hatched from the eggs of quails in the control group, whose food was free from DDT. Thus, the difference between quails consuming food with DDT and the control group was only 3.9%, which did not make it possible to draw a conclusion regarding the effects of DDT on reproductive function in birds. Much later it was found that DDT causes thinning of egg shells and the death of embryos. However various groups birds vary greatly in their sensitivity to DDT; birds of prey show the greatest sensitivity, and in natural conditions A marked thinning of the shell can often be detected, whereas chicken eggs are comparatively insensitive. Because of Carson's omissions in her book, most experimental studies were done with DDT-insensitive species (such as quail), which often showed little or no shell thinning. Thus, Carson's book misdirected science by targeting birds that were not sensitive to the effects of DDT, thereby delaying research into the effects of DDT on birds by 20 years. However, we can now talk about the impact of DDT on the environment from a scientific point of view.

Degradation resistance

DDT is highly resistant to decomposition: neither critical temperatures, nor enzymes involved in the neutralization of foreign substances, nor light are able to have any noticeable effect on the decomposition process of DDT. As a result, when DDT enters the environment, it somehow enters the food chain. Circulating in it, DDT accumulates in significant quantities, first in plants, then in animals and, finally, in the human body. Calculation by Dahmen and Hayes (1973) showed that at each link in the food chain there is a 10-fold increase in DDT content:

Plants (algae) - 10x

Small organisms (crustaceans) - 100x

Pisces - 1000x

Predatory fish - 10000x

This rapid accumulation of DDT is clearly visible from following example. Thus, in a study of one ecosystem in Lake Michigan, the following accumulation of DDT in food chains was discovered: in the bottom silt of the lake - 0.014 mg/kg, in crustaceans feeding on the bottom - 0.41 mg/kg, in various fish- 3-6 mg/kg, in the adipose tissue of seagulls feeding on this fish - over 200 mg/kg.

Impact of DDT on humans

Available data on the toxic effects of DDT in humans can be summarized as follows. DDT has an acute toxic effect on humans: in small and medium doses it causes poisoning, in adults mostly without negative consequences in the future, in large doses it can cause death. DDT accumulates in the fatty tissues of the body, enters mother's milk, and can enter the blood. Theoretically, with weight loss, or due to prolonged exposure, the accumulation of DDT in the body can lead to intoxication of the body. Objectively, the consequences of DDT accumulation in the human body have not been established. The effect of DDT on the human body does not have carcinogenic (causing cancer), mutagenic (causing permanent changes in living matter), teratogenic (causing deformity), embryotoxic (causing changes in the fetus) effects, and does not lead to a decrease in fertility (the ability to have offspring). DDT leads to the induction of microsomal enzymes, but does not entail any morphological changes in the liver, and enzymatic activity generally does not exceed the norm. The effect of DDT on the human immune system appears to be inhibitory in nature (inhibits the activity of enzymes, in in this case inhibition of antibody formation), but this has not been definitively established.

It should be noted that many popular scientific sources contain categorical statements about the carcinogenic, mutagenic, embryotoxic, neurotoxic, immunotoxic effects of DDT on the human body. For example, DDT is alleged to cause or contribute to a variety of human diseases that were not previously thought to be associated with any chemical. These include cardiovascular disease, cancer, atypical pneumonia, retrorental fibroplasia, poliomyelitis, hepatitis and "neuropsychiatric manifestations". At the time these claims were made, the causes of each and every one of these diseases were unknown, or at least not proven. Needless to say, the accusation that DDT predisposes to polio was refuted after the disease was brought under control through vaccination. Unfortunately, today there is no immediate possibility of combating cardiovascular diseases, cancer and many other less common human pathological conditions, the occurrence of which was attributed to DDT. Meanwhile, such irresponsible statements can cause great harm and, if taken seriously, can even interfere with the scientific search for the true causes and real measures to prevent these conditions.

Impact of DDT on other living organisms (except humans)

Available data on the toxic effects of DDT on other living organisms can be summarized as follows. Aquatic microorganisms are more sensitive to the effects of DDT than terrestrial ones. At a concentration of environment 0.1 µg/l DDT can inhibit the growth and photosynthesis of green algae.

Indicators of both acute and chronic toxicity for various types aquatic invertebrates are not uniformly affected by DDT. In general, DDT is highly toxic to aquatic invertebrates at acute exposure levels as low as 0.3 µg/L, with toxic effects including reproductive and developmental impairment, cardiovascular changes, and neurological changes.

DDT is highly toxic to fish, with LC50 values ​​(96 h) obtained in static tests ranging from 1.5 µg/L (largemouth bass) to 56 µg/L (guppy). Residual levels of DDT above 2.4 mg/kg winter flounder eggs caused abnormal embryo development; Similar residual concentrations were found to be associated with the death of lake trout fry under natural conditions. The main target of the toxic effect of DDT may be cellular respiration.

Earthworms are not sensitive to the acute toxic effects of DDT at levels above those likely to be present in environmental conditions.

DDT can have an adverse effect on the reproductive function of birds, causing the thinning of egg shells (which leads to their destruction) and the death of embryos.

Some mammal species, especially bats, may be adversely affected by DDT. The bats, caught in nature (in which residual DDT was found in their adipose tissue), died as a result of artificial starvation, which served as a model for fat loss during migratory flights.

In addition, the carcinogenic, teratogenic and immunotoxic effects of DDT on some living organisms have been established.