Allergen h1 - house dust (Greer), IgE (ImmunoCAP). Where does the dust in the apartment come from and how to deal with it? What causes dust in the air

Have you begun to notice that the skin of your hands dries out and no creams can save the situation? Runny nose stubbornly resists nasal drops and does not go away for weeks? Do you swallow vitamins in handfuls, but still constantly feel lethargic? Perhaps it's not a weakened immune system, but dust.

Composition of household dust

Dust - what is there in it! Ordinary household dust consists of dozens or even hundreds of types of particles of various origins. Approximately one third of the dust consists of mineral particles, 20% of dead skin flakes. We shed dead cells constantly, and over the course of a lifetime, an average person loses about 18 kilograms of dead cells. Another 12–15% are the smallest textile fibers. Their source is carpets, curtains, our clothes, wallpapers, soft toys, upholstery of sofas and armchairs. The more such objects in the house, the more dust is formed in it. 7–10% of household dust is plant pollen, mold spores and other plant particles. The rest are microscopic globules of grease that stick other dust particles together and prevent cleaning, pet hair if you have any, and a huge number of microorganisms and tiny insects.

Where does house dust come from?

Where is there more dust - in a metropolis or in the bosom of nature? According to statistics, a city dweller inhales about a billion dust particles per minute, while a rural dweller breathes only 40 million. Therefore, it is the citizens who should pay special attention to the cleanliness of the house. The harm of house dust is not a myth, but a very real danger.

However, the most common harm to household dust is allergies. The most optimistic statistics says that every tenth inhabitant of the Earth is allergic to dust. But some believe that about 40% of people suffer from it. And this seems to be true, because often even the patients themselves do not suspect that the cause of their ailment is ordinary household dust. Dust allergy symptoms are often confused with the common cold. There really is something in common - this disease is manifested by a chronic runny nose, sore throat, sneezing, inflammation of the mucous membranes, dry cough and redness of the eyes. Allergic dermatitis is also not uncommon, when the skin becomes very dry, irritated and sensitive, itching or characteristic blisters occur - the so-called urticaria.

In the worst case, allergies can provoke the development of bronchial asthma - a very dangerous disease that every year in our country alone takes the lives of 5,000 people, mostly children.

Why does dust cause allergies? It's all about its ingredients. Mold spores and plant pollen are powerful allergens - everyone who suffers from hay fever in the spring and cannot calmly smell bird cherry knows this. But plants bloom only once a year, and dust surrounds us all the time. However, dust allergy is most often caused not by flora, but by fauna - insects that live in every lump of dust.

If you follow all these recommendations, you can not only make life easier for family members who are allergic to dust, but also completely get rid of this disease over time. Sometimes, if the allergic person manages to avoid contact with the allergen for a long time, the allergy disappears forever.

Do you know...

The Association of Home Appliance Manufacturers (AHAM) has certified the Rainbow system as an air purifier. No other vacuum cleaner has received such a certificate.

Do you know...

Permanent residence in a dusty room can become a factor in the occurrence of pneumoconiosis, fibrosis, and even lung cancer. In order to reduce the risk, it is worth getting rid of the abundance of napkins, decorative pillows and soft toys in the house, as well as cleaning with a vacuum cleaner at least once every two weeks.

I want to share with you information about house dust, or rather about its danger, if no measures are taken.

Maryland Medical Research Laboratory house dust analysis

Taking five bags, the hostess collected samples: one ball of dust from under the bed, another from the blades of the ceiling fan, the third from under the stove, the fourth, velvety green, found on the intake grate of the air conditioner. Finally, the journalist took the fifth ball from under the radiator from a neighbor, a bald bachelor, who also does not keep any dogs or cats, which made it possible to find a rare sample of house dust, obviously containing neither hair nor wool.

Having delivered her samples to the laboratory, the journalist gave them for analysis and, while pre-processing was in progress, asked the employees about the subject of their research. She learned that there were several hundred books published in the world on all kinds of dust.

Among these volumes there is even the work "Dust and Law" - a review of cases from judicial practice related to dust. This book tells, in particular, about the case when the dust was used to expose the impostor.

One millionaire, dying, bequeathed his fortune to his son, whom he had not seen for many years. Two people presented their rights to the inheritance, both with credible documents. To find out which of the two is the real heir, they found a pediatrician who had treated the son of a millionaire many years ago.

He was unable to identify the real heir, but after looking at the child's preserved medical record, the doctor came up with an interesting idea. He sent both applicants to the cellar to shovel coal. When they went upstairs, the doctor pointed out one of them, on whose face small white spots appeared through a layer of coal dust. This is the rightful heir, said the doctor. In the case history it was written that he had smallpox. And although small pockmarks were not noticeable, the physician knew that the dust did not stick to them, and they would appear.

Experts estimate that 43 million tons of dust settle in the United States every year. Moreover, approximately 31 million tons are of natural origin, and the remaining 12 million are the result of human activity.

The most important source of dust- the soil. In second place are the oceans, throwing small salt crystals into the air. Estimates of the total mass of these grains of salt range from 300 million to 10 billion tons per year. Of course, it is not the crystals themselves that are ejected, but the smallest droplets of water that arise when the sea is rough and when air bubbles rising to the surface are destroyed. The droplets dry up and the air becomes saturated with salts. Most of the crystals rise high into the air and serve as nuclei for the condensation of water vapor. If there were no dust in the air, there would be no clouds.

The third largest source of dust is volcanoes. They produce the largest dust particles. The famous eruption of the Krakatau volcano on August 26-28, 1883 (see "Science and Life" N7 1984) threw more than 18 cubic meters into the atmosphere. km of crushed rocks, and part of this mass flew to a height of up to 40-50 km. Three months later, dust from Indonesia, where the volcano is located, flew to Europe, and for another three years, daylight throughout the earth was dimmer than usual, and sunsets and sunrises were more picturesque, crimson, thanks to the scattering of light on fine dust particles.

Larger dust particles, such as those released into the atmosphere during large forest fires, produce a bluish haze, scattering red light, passing the blue part of the spectrum. The sun then appears cold and the moon blue.

A major source of volcanic dust is the Japanese volcano Sakurajima on the island of Kyushu. Its last major eruption took place in January of this year, but the volcano is constantly smoking, annually releasing about 14 million tons of dust into the atmosphere. The nearby city of Kagoshima is considered the most dusty city in the world, its streets are always covered with dust and ash.
An important source of dust for the entire globe is the Sahara Desert (see "Science and Life" N2, 1985). Rains with pinkish dust, brought by the wind from the Sahara, fall in both England and Florida. Dust from the Sahara colors the snow on the mountains of Central America. The wind annually raises from 60 to 200 million tons of dust in this largest desert in the world. Samples of all these types of dust are available in any apartment. There is even extraterrestrial dust, mainly from comets and meteorites, which increases the mass of the Earth by 10 tons annually. There is also flower pollen. Especially a lot of it turned out to be in the air conditioner, which sucks in air from the street. In the dust from under the stove, under a microscope, crystals of boric acid were found, which is used as a remedy for cockroaches.

There was also some yeast, cat hair, pollen and a lot of blue and pink fibers, as explained by a specialist from natural tissues. In the dust from under the battery from the neighbor's apartment, they found blue synthetic fibers - possibly from underwear. Natural fibers differ from synthetic ones in their less smoothness and flattened irregular structural shape.

“But in the dust from under the bed they found something terrible, something like a microscopic rhinoceros with crayfish claws. All laboratory staff came running to see the curiosity. After heated discussions and searching in books, they came to the conclusion that this is one of fifty mites known in the world that live in house dust.

These microscopic creatures live in our mattresses, pillows, beds and upholstered furniture, in accumulations of dust on the floor. They are difficult to see with the naked eye. These mites feed on the 50 million skin flakes that slough off each of us every day. They cannot feed on living skin; they need precisely its fallen, withered particles, which has been proven in experiments. Several hundred of these mites, in a flat container open on one side, were bandaged to the experimenter's hand. A few days later, all individuals were dead - living skin did not suit them.

From apartment to apartment, ticks are carried by drafts, carried on clothes, shoes or furniture, but moving on their own to a neighboring house is the same for them as a person crossing the United States on foot.

It is estimated that in the average double bed there are about two million of them. They do not cause harm, although in some people these mites secrete up to 20 microscopic peas per day and cause allergies.

A Japanese company has started producing a vacuum cleaner that not only collects dust along with mites, but also heats the collected dust, killing mites. This, according to the inventors, prevents the resettlement of mites from the dust collector around the apartment.

Without such a vacuum cleaner, Penny Moser decided not to pay any attention and pretend that she did not know about them in the same way that she did not know before visiting the laboratory. “That night, as always, my husband, my cat, and two million ticks slept comfortably in our bed.”

The fact that in some people house dust can cause allergic reactions for a long time, but only about twenty years ago it became known that allergies are caused not by the dust itself, but by microscopic mites living in it, 70-80% of which are bed mites. To combat these mites, it is necessary to ventilate, iron, or warm up bed linen, pillows, mattresses, blankets more often - these arthropods are afraid of both cold and heat, say a temperature of plus 40 ° C kills them in two days, and a higher one is much faster.

They are also afraid of the direct rays of the sun, and ultraviolet radiation not only kills ticks, but also decomposes the allergens contained in them and their excrement in two hours (these allergens withstand an hour of boiling in water without disintegrating). With a strong infestation, you have to change all pillows and, preferably, new ones with synthetic stuffing (feather stuffing for some types of ticks serves as an additional source of food).

Although bed mites do not disperse far from their habitat, in an apartment heavily infested with them, it is advisable to wash the floor with a 10-20% solution of table salt. And once a month, pickle house slippers, where they also find shelter, food, and a means of transport to neighboring rooms with formalin vapors or vinegar essence, tying the slippers for a while in a plastic bag with a few drops of liquid at the bottom. Insecticides are not used, since their effect is short-lived and dangerous to humans.

In houses of modern construction, where we suffer from great dryness of the air, dust mites are almost or completely absent - they need high humidity. Therefore, by the way, they are not afraid of wet cleaning, but their number decreases after dry cleaning.

Particles from the dust balls brought to the laboratory were placed on various nutrient media, and after a few days interesting cultures grew - a variety of mold fungi, as well as bacteria.
The most interesting result was dust from the fan and from the air conditioner, spores of the causative agent of gangrene were found here. The experts explained that these spores are carried by the wind and can get anywhere, but will only cause gangrene if they get into a deep wound where oxygen cannot penetrate. These microbes can only reproduce in anoxic conditions.

An important component of all samples was rubber dust from tires rubbed against asphalt and concrete. As a rule, its clouds do not rise above the fourth floor, and at the level of the seventh floor it is almost gone. The average inhabitant of a large city inhales about 500 billion dust particles daily, and among them there are many rubber ones. Although most of these particles are immediately exhaled, a lot remains in the nose, larynx and lungs.

Our body has a good defense against dust particles. They stick to the mucus that covers the surface of the respiratory tract and, together with this mucus, to the exit - into the larynx. They are driven by countless cilia that line the lining of the respiratory tract. These cilia synchronously perform wave-like movements that bring all microscopic particles that have got inside the lungs out. Coughing and expectoration removes them. However, if the dust content of the air exceeds the norm, this system cannot cope.

When dust storms raged in the western United States due to predatory prairie cultivation in the thirties, the lungs of many local residents were so clogged with earth that they could not cough. After treatment to widen their spasmodically contracted airways, these people coughed up pencil-thick rolls of packed dust from their bronchi. The air inside the house is always more dusty than outside, unless you live in a large industrial city.

House dust video

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General information about the study

An allergen is a substance that causes an allergic reaction. There are a huge number of substances of natural or artificial origin, each of which can become an allergen for humans.

The main participant in the immediate type (type 1) allergic reaction is immunoglobulin class E (IgE). For each allergen, there is a specific immunoglobulin E. The purpose of this test is to determine an allergic reaction to house dust (Greer Labs., Inc. allergen). Its most important components are mites of the Pyroglyphidae family. These include Dermatophagoides farinae, Dermatophagoides pteronyssinus and others.

House dust mites are one of the most common causes of conjunctivitis, an atopic dermatitis. They can be found in mattresses, carpets, etc. As a rule, mites feed on dead skin particles that a person loses daily. The waste products of ticks are digestive enzymes: proteins Derf1 and Derp1. They contribute to the destruction of human skin cells and can cause allergic reactions.

These substances enter the body by inhalation, with an increased concentration of dust in the air or by contact with products that contain an allergen (clothes, pillows, blankets). Allergy symptoms can be as follows: redness (hyperemia), skin rashes, itching, swelling and swelling of the skin, redness and burning of the mucous membrane of the eyes, lacrimation, swelling of the eyelids, sneezing, coughing, shortness of breath, bronchospasm.

The analysis is safe for the patient compared to skin tests (in vivo), as it eliminates contact with the allergen. In addition, the use of antihistamines and age characteristics do not affect the quality and accuracy of the study.

Quantitative determination of specific IgE antibodies makes it possible to assess the relationship between the level of antibodies and the clinical manifestations of allergy. Low values ​​of this indicator indicate a low probability of an allergic disease, while a high level has a high correlation with the clinical manifestations of the disease. When detecting high levels of specific IgE, it is possible to predict the development of allergies in the future and a more pronounced manifestation of its symptoms. However, the concentration of IgE in the blood is unstable. It changes with the development of the disease, with the amount of dose of allergens received, as well as during treatment. It is recommended to repeat the study when symptoms change and when monitoring ongoing treatment. The need for re-examination should be consulted with the attending physician.

ImmunoCAP is characterized by high accuracy and specificity: even very low concentrations of IgE antibodies are detected in a small amount of blood. The study is revolutionary and based on the immunofluorescent method, which allows to increase the sensitivity several times compared to other tests. The World Health Organization and the World Allergy Organization recognize ImmunoCAP diagnostics as the "gold standard", as it has been proven to be accurate and stable in independent studies. In the Russian Federation, the technique has not yet become widespread, although worldwide up to 80% of tests for class E specific immunoglobulins are performed using ImmunoCAP.

Thus, the detection of specific IgE using this technique brings allergy diagnostics to a qualitatively new level.

What is research used for?

• For the diagnosis of allergic diseases (bronchial asthma, allergic rhinitis, respiratory allergy, atopic dermatitis).
• To assess the risk of developing allergic reactions to house dust (Greer).

When is the study scheduled?

• In the presence of the following symptoms indicating an allergic nature: redness and burning of the mucous membrane of the eyes, lacrimation and swelling of the eyelids, nasal congestion, sneezing, coughing, shortness of breath, bronchospasm, etc.
• Children - if their parents suffer from allergic diseases, including those manifested by contact with house dust (Greer).
• With a continuously relapsing course of respiratory diseases without periods of remission.
• With the polyvalent nature of sensitization, when it is not possible to conduct in vivo testing with suspected allergens.
• False-positive or false-negative skin test result.

Everyone knows that there is always dust in the air we breathe. It surrounds us with an invisible (and sometimes very visible) cloud, consisting of various microparticles. What is the percentage of dust in an urban atmosphere on a typical day? What determines the migration route of dust particles and what can prevent the “dusting” of the city?

Dust is like fog, only dust. If fog is a mass of small droplets of liquid suspended in the air, then dust is solid particles suspended in the air with a size of the order of a tenth of a micrometer. The dust in the city is made up of everything that is possible: from pieces of soil and sea water salts to volcanic emissions.

But in general, on a typical Moscow day, the amount of “local” dust in the atmosphere is about 70 percent. Basically, we, the inhabitants of the metropolis, are stuck not with particles of sand or soil, but with emissions of fuels and lubricants, dust from erasing car tires on asphalt, and in winter also reagents that are sprinkled on roads. It is clear that on days when another forest or peat bog burns somewhere in the Moscow region, the amount of dust in the capital increases. For example, during the summer of 2010, which you will surely remember, the dust content in the city exceeded the norm by dozens of times. And a few months ago, we all carried on our shoulders not one or two particles of the burnt INION.

Their migration routes also depend on the size of the dust grains.

Large and medium particles, larger than 1 micron, land on a new place within a day or several hours, and during this time they do not move far from their previous place of residence. They travel, for example, between the Butovo courtyard and the Tula streets. Small particles can stay in the air for up to 20 days, overcoming great distances. Today they are over Moscow, and after some time - over Vladivostok.

Independent air monitoring in Moscow shows that with a period of 7-10 days, the dust content changes by 1.5-3 times, and from May to August, the average amount of dust and fluctuations in its amount in the air are much less than in the period from September to April .

Our body is not able to filter out dust smaller than 2.5 micrometers. It freely passes through the respiratory tract and enters the lungs.

In 2010, Canadian scientists published in the journal Environmental Health Perspectives a map of the concentration and distribution of dust particles that can pose a risk to human health. They used satellite data to obtain the data. The highest level of "dust threat", according to their data, are the territories of North Africa and Asia Minor. And the most dangerous region of this kind was the territory in the north of China. Which is famous not for its deserts, but for the morning smog.

The World Health Organization claims that an average of 7 percent of heart attacks worldwide are due to air pollution like dust. And reducing this pollution by 10 milligrams per cubic meter by 2 percent reduces the risk of death of local residents from heart attacks. And although these numbers are not high, in themselves they serve as a wonderful testament to the importance of even such a trifle as dust for our health.

Dust, the origin of which is less related to human activity - particles of soil and sand - is much easier to deal with than dust of industrial origin. Landscaping of wastelands, courtyards and other urban areas is the most effective method here. The “living” site not only strengthens the soil and prevents the city from becoming dusty, but also absorbs and recycles dust particles already in the air.

Dust on the matrix of a SLR camera is an unpleasant thing, but far from fatal. The designs of DSLRs are far from perfect tightness, so dust ingress is inevitable. And even if you have never removed a camera lens, this does not mean at all that the matrix of your camera will remain pristine. Sometimes the presence of dust on the matrix is ​​so insignificant that without looking closely you will not even know about its existence. But there comes a moment when the dust begins to show itself in all its glory. Dust on the matrix becomes more noticeable when shooting at a closed aperture. So in a picture taken with an aperture of 22, you can see the smallest dust particles.

And so, if you want to look at the dust on the matrix of your camera. We switch to the “A” (aperture priority) or “M” mode, set the aperture to 20, IS0 100. When using the “M” mode, the shutter speed is set according to the exposure meter, in the “A” mode the shutter speed will be set automatically. We are looking for a solid background (preferably a neutral gray or white sheet of paper) and take a picture. Focusing is not required.

If there is coarse dust on the matrix, then it can be immediately seen in the photo using the camera display.

But if you want to see the full picture, then you need to use an editor that allows you to work with curves or levels. I use Lightroom and its Tone Curve tool. On the tone curve, we shift the points as close to the center as possible:

Or using levels in Photoshop:

And here you will see the full picture.

Do not rush to faint, all cameras have dust on the matrix. When there are few dust particles on the matrix and they are small, it is easier to remove them with retouching tools in processing programs. But if the camera matrix has turned into a "starry scattering of the night sky" and the dust in the pictures has begun to annoy you, then it's time for cleaning. In my case, the last straw was a black dot, clearly visible to the naked eye, just above the center of the image.

I prefer to clean the matrix myself. How to clean the camera matrix yourself at home? For cleaning I use a pear (syringe) and, in extreme cases, cotton swabs. I bought a pear for cleaning the matrix in a regular pharmacy, so it's 5 times cheaper. I heard that it is not recommended to use such pears, since they may contain talc residues and, on the contrary, you can cover the matrix with dust.

To clean the sensor, remove the lens and raise the mirror. To do this, we find in the menu the corresponding item “Raising the mirror for cleaning”.

First, we try to get rid of dust using a pear. We thoroughly blow the matrix by actively working with a pear. After that, we put on the lens and take another picture with the parameters indicated above. And we do manipulations with levels or curves. If the result is satisfactory, then the cleaning is over. If the result is still unsatisfactory, we continue to repeat the operation with the pear. With severe pollution, there will definitely be dust particles that bite into the matrix with their teeth. To such dust particles I apply "physical violence" using a cotton swab.

The complexity of cleaning the matrix is ​​due not so much to the amount of dust on the matrix, but to the time that has passed since the moment of contamination. I noticed that if you do not delay the removal of dust, then you can get rid of it by simply blowing a pear. But in the case when I postpone cleaning, the use of a cotton swab is inevitable. For more severe pollution, special solutions are used, but I have not yet encountered such pollution, so I can’t talk about their use. I finish cleaning the matrix when an acceptable result is achieved. A few small dust particles are quite acceptable, since they are not visible on open diaphragms. That is, I eliminate especially “harmful” dust particles that are striking in all photographs.

If you are unsure of your abilities, it is better to give the camera to the service than to change the damaged matrix later due to a mistake.