Asbestosis - causes and symptoms, treatment and prevention of asbestosis. Asbestosis: symptoms, diagnosis, treatment How and how asbestosis is transmitted

Occupational diseases caused by exposure to the dust factor, silicosis

asbestosis

Asbestosis is called pneumoconiosis, which develops from the inhalation of asbestos dust. Asbestos is a mineral with a fibrous structure. Its chemical structure consists of magnesium and silicon salts, sometimes with an admixture of calcium oxide, aluminum and other elements.

Due to its valuable quality - fire resistance, high strength, low thermal conductivity, acid and alkali resistance - asbestos has become widespread in industry. It is applied to the manufacture of thermal insulation materials, slates, pipes, brake bands, etc.

Asbestos dust is formed both during the extraction of asbestos and during its processing (crushing, loosening, spinning, etc.).

Asbestosis develops more often in workers with 10 years of experience in contact with asbestos dust. Only in rare cases, the disease occurs in people with less experience. The clinical picture of asbeetosis resembles silicosis, but in the first case, the phenomena of bronchitis and emphysema are more pronounced.

One of the first signs of asbestosis is shortness of breath. It appears initially during physical exertion, and with the progression of the process, it is also observed at rest. The ventilation of the lungs is disturbed. Another characteristic complaint in asbestosis is a cough - dry or with a small amount of viscous sputum difficult to separate. Asbestos bodies are sometimes found in sputum, which are formed as a result of the chemical transformation of asbestos fibers. The third most common complaint is chest pain. The disease is usually accompanied by general weakness, fatigue, headaches, and dyspeptic symptoms.

Characteristic appearance of patients with asbestosis. The complexion acquires a gray-earthy tint, the lips are cyanotic. Asbestos warts may appear on the skin of the fingers and toes. Significant weight loss is noted.

Auscultatory changes in the lungs are caused by bronchitis, emphysema and pneumosclerosis. Breathing is hard or weakened, often with an extended exhalation. Abundance of dry whistling buzzing rales; there are also moist rales. Emphysema in asbestosis is more pronounced in the upper sections, in contrast to silicosis, in which basal emphysema develops. Asbestosis is often accompanied by bronchiectasis "disease and interstitial" pneumonia. Respiratory failure is noted already in the early stages of the disease. In an advanced stage of the disease, cor pulmonale develops.

In asbestosis, in contrast to silicosis, clinical signs are significantly ahead of radiological ones. According to the clinical and radiological picture, stage I, II and less often III stage of asbestosis are distinguished.

At stage I, patients complain of shortness of breath during normal work, intermittent cough, chest pain. There is a box shade of percussion sound, hard breathing, dry wheezing. X-ray reveals an increase in the vascular-bronchial pattern, a decrease in transparency in the middle and lower parts of the lungs, a soft mesh pattern, emphysema, mainly in the upper parts of the lungs, expansion and compaction of the roots.

In stage II asbestosis, shortness of breath occurs during normal walking, coughing intensifies, and viscous sputum is separated. With percussion, the box tone of the sound is more pronounced. Breathing is hard, an abundance of dry rales in all lung fields. There may be a pleural friction rub. X-ray changes in this stage are more pronounced. The transparency of the middle and lower parts of the lungs is significantly reduced, the lung pattern is reticulated. Sometimes small spotting is determined. Emphysema is more pronounced in the upper sections of the lungs. Pleuropericardial and pleurodiaphragmatic adhesions are determined.

In stage III asbestosis, shortness of breath is observed at rest. Disturbed by constant painful cough with sputum, pain in the chest. Pronounced cyanosis. Percussion sound box. The mobility of the lung edges is sharply limited. Breathing is hard, weakened in places. Abundance of dry and moist rales. The heart sounds are muffled, the accent of II tone is on the pulmonary artery. Radiologically, significant interstitial changes are noted, as well as inhomogeneous darkening, more often in the middle sections, merging with the roots of the lungs. Pleural changes are expressed.

The course of asbestosis is progressive. Death occurs from decompensated cor pulmonale. Unlike silicosis, asbestosis is rarely complicated by tuberculosis. Asbestosis is known to predispose to the development of lung cancer.

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Etiology. Asbestos is a mineral containing 40-60% silicon in the form of calcium, magnesium, iron, sodium silicates without the participation of SiO2. Natural asbestos is mined in Canada, South Africa, China, Italy and the United States of America.

There are two forms of asbestos. Amphibole or hornblend (amphiboloasbestos, tremolite, amosite, crocidolite) have short fibers, are acid-resistant, but less resistant to elevated temperatures, melt at a temperature close to 1150 °. Another variety of asbestos is serpentine (serpentine asbestos, chrysolite, white asbestos) has long fibers that are easily separated, poorly conducts heat, is resistant to high temperatures (melts at a temperature of about 2750 °), but is less resistant to chemicals.

Varieties of asbestos with long fibers are used in industry as a raw material for the production of threads and asbestos fabrics. Tow is produced from short-fiber asbestos, which is used for sealing gaps in motor and machine industries, as well as in the construction of refractory installations (asbestos cement, roofing slabs, etc.). Air pollution with asbestos dust is observed during the grinding of raw materials in textile asbestos production, during preparatory work when combing the fiber. Asbestos dust consists of fibers in the form of needles, from 1 to 400 u long, from 15 mu to several microns thick. The incidence of asbestosis increases in proportion to the concentration of dust in the air and the number of years worked in the workplace associated with asbestos dust.

Pathogenesis. The development of asbestosis is different from silicosis. In this disease, a number of phenomena are observed that have not yet been clarified. It is still unknown why asbestos needles up to 200 u long do not stay in the airways and get inside the vesicles. During respiratory movements, the needles touch the walls of the vesicles, injure them and penetrate into the depths of the lung tissue until they come across the interalveolar septa, walls of blood vessels or bronchi. This mechanism explains the randomness in the distribution of asbestos needles in the lungs. After a few months, usually up to a year, asbestos needles in the lung are covered with a protein shell and transformed into club-shaped or dumbbell-shaped asbestos bodies. Lymphocytes, plasma cells, macrophages, giant cells accumulate around these bodies, and then collagen fibers are formed, which are arranged randomly. Over time, a fibrous connective tissue is formed, poor in cells. The most probable hypothesis is that the tissue fluid washes Mg and Fe cations from the surface of the crystal network of the asbestos needle and the released bonds combine with the protein substance in the form of sols that gradually absorb Si02, which cause fibrotic reactions.

Pathological anatomy. The lower lung fields, in later periods, the middle and even the upper ones, are covered with scattered fibrous changes in the stroma, the stripes of these blackouts intersecting can imitate focal blackouts, and over time increase and form large foci of fibrosis. Aging, fibrous tissue causes deformation of the bronchi and the development of emphysema. The pleura thickens, semicircular foci of cartilaginous hardness form on it. On microscopic preparations, a characteristic feature is the presence of asbestos needles and asbestos bodies among the lung tissue.

Clinic. An early symptom of asbestosis is a painful, dry cough and very rarely expectorated stinging sputum, in which asbestos bodies can be found, indicating that a person inhales asbestos dust. Over time, shortness of breath appears on the nerve plane during exercise, less often there are pains at the base of the chest cavity.

On physical examination, sometimes shortened percussion sound in the lower lung fields and symptoms of emphysema, sometimes bronchitis. In workers working in asbestos dust, "asbestos warts" form on the skin of the fingers and palms, rough, the size of millet or black pepper grain, without inflammatory features. Warts occur near asbestos needles driven into the skin, which irritate the skin. If the asbestos needles are removed, the warts disappear.

Radiography. At the beginning of the disease, changes are visible on the lateral and lower parts of the lower lobes of the lungs in the form of a delicate mesh or small tender stripes and a weak intensity of focal changes (stage I). Over time, the mesh becomes rough and, together with the thickened pleura, covers the lungs with a veil, against which numerous small foci of emphysema are visible, forming a picture resembling foam. Horizontal and oblique stripe-like shadows appear on the lateral parts of the lung fields. The upper lung fields, in relation to the lower lung fields, are contrastingly emphysematous. The contours of the heart and diaphragm become blurred, indistinct (stage II).

In the last stage III, the darkening of the lower lung fields becomes intense and it is often impossible to determine the boundaries of the diaphragm and heart. The upper lung fields are largely emphysematous. Hilusnye shadows almost during the entire time of illness remain unchanged. It is difficult to draw a clear radiological boundary between the three stages of the disease.

Functional disorders in asbestosis. It can be concluded that there is a violation of ventilation (low spirometry data), reduced lung distension and difficulty in gas exchange (increased vesicular-arterial gradient).

Clinical course the disease is slow, the first symptoms appear after several years of work in asbestos dust. The further course of the disease sometimes develops faster than with silicosis and leads to chronic respiratory decompensation and circulatory decompensation. The disease is necessarily accompanied by emphysema and bronchitis. It has not been noted that asbestosis contributes to the development of tuberculosis, but with asbestosis, lung cancer is observed much more often than in other people.

Asbestosis is an occupational disease from the group of silicates. The immediate cause of its development is the inhalation of dust containing asbestos. The latter is a natural material and in Greek means "indestructible". This collective concept combines all minerals from the class of silicates with a fine-fiber structure (chrysotile, anthophyllite, amosite, crociodolite). There are several types of asbestos in nature (the most famous of them are blue and white), and all of them are capable of causing pathology of the respiratory system in humans.

Due to its strength and fire resistance, asbestos is widely used in industry and in the manufacture of building materials. Pipes, slate, panels, various technical products are produced from it. It is used for thermal insulation of water pipes, water heating and heating boilers, as well as for the manufacture of fire safety products.

Causes and mechanisms of development

The disease is more susceptible to persons engaged in the extraction of this mineral, its processing and the manufacture of various products from it. This pathology is most common in Canada, which is the leader in asbestos reserves among all countries of the world.

Moreover, pneumoconiosis develops not only in persons who have prolonged contact with the mineral. There are known cases of illness with occupational harmful experience of less than 3 years and even 20 years after contact with asbestos. The literature describes cases of pneumoconiosis with very little contact with a damaging agent - in workers (for example, painters or electricians) who are in the same room with insulators. In addition to professional contact, sometimes there is a household one. It is even possible to develop the disease in women who inhaled asbestos-containing dust while washing the clothes of their husband, who works in a hazardous industry.

The mechanism of development of pathological changes in the lungs in asbestosis is not completely clear. The literature describes several aspects of the negative impact of asbestos dust on the respiratory system:

• mechanical irritation and damage;
• fibrosing action;
• damage to lung tissue as a result of the release of silicon compounds;
• immunopathological reactions;
• carcinogenic effect, etc.

The latter should be given special attention. According to most scientists, not all asbestos fibers are capable of causing cancer. It depends on the length of the fibers. If their dimensions exceed 5 microns, then such properties are not typical for them, while shorter fibers (3 microns or less) have a pronounced carcinogenic effect. Asbestos has been proven to potentiate the action of other carcinogenic substances.

In persons suffering from asbestosis, the risk of lung cancer increases by about 10 times, if such people are also active smokers, then by 90 times. Asbestos fibers penetrate deep into the alveoli (especially in the basal sections) and damage their walls, creating a premorbid background. Also, in this category of patients, cancer of other localizations is more often detected -, and.

Clinical signs

The clinical picture of asbestosis is due to pathological changes in the lungs associated with the inhalation of dust containing this mineral. At the same time, and come to the fore, pneumofibrosis is also observed.

The disease usually manifests itself in the early stages. However, in some patients it is asymptomatic or reminds of itself many years after the cessation of work in harmful conditions.

Asbestosis is characterized by:

• early appearance (first occurs during physical exertion, later worries at rest);
• obsessive cough in the form of attacks (first dry, then with sputum difficult to separate);
• chest pain (with involvement of the pleura);
• violation of the general condition (causeless weakness, increased fatigue, frequent headaches);
• change in appearance (, earthy-gray color of the skin, cyanosis of the lips).

A peculiar sign of the disease is the presence of asbestos fibers in the sputum and the formation of a special type of warts on the skin. However, this is not observed in all patients. Asbestos fibers appear in sputum upon contact with the mineral, their presence indicates self-purification of the lungs from foreign substances. Asbestos bodies can also form in the sputum, which, in all likelihood, are part of the mineral fibers that have changed their structure under the influence of the environment.

Asbestos warts can appear in such patients on the arms and legs as a result of the introduction of mineral fibers into the integumentary epithelium. In this zone, pronounced keratinization is noted, and in the underlying tissues - chronic inflammation.

With prolonged contact with asbestos, complications may develop in the form of:

• formations;
• suppurative processes in the lungs;
• torpidly flowing forms (rare);
• severe respiratory failure;
• cor pulmonale;
• oncological diseases (, cancer of the esophagus, stomach or intestines).

A malignant tumor process in the lungs is combined with asbestosis much more often than with other diseases of dust etiology. It develops 20-50 years after contact with a harmful factor and is more common in men. A cancerous tumor is usually detected in the lower lobes, where asbestos dust settles.

stages

The severity of symptoms in asbestosis may vary depending on the stage and nature of pathological changes in the lung tissue. Its course is conditionally divided into 3 stages:

• On the first of them, the patient has initial signs of emphysema and insufficiency of respiratory function. He is worried about shortness of breath, coughing and discomfort in the chest. Intermittent dry rales and pleural friction rub are heard above the lungs. There is an increase in the pulmonary pattern, fine-loop fibrosis and slight changes in the pleura.
• The second stage is manifested by a coarser change in the pulmonary pattern, nodular shadows, expansion and compaction of the roots of the lungs, and the formation of pleurodiaphragmatic adhesions. This is due to developing emphysema and pneumofibrosis. In patients, respiratory failure increases, shortness of breath and cough increase, cor pulmonale begins to form. On auscultation, along with dry rales, moist rales are heard.
• With stage 3 asbestosis, severe respiratory failure with dyspnea at rest and cyanosis is noted. Most patients have decompensated cor pulmonale. The chest becomes barrel-shaped. The images reveal diffuse pneumosclerosis and emphysema, as well as signs of chronic cor pulmonale.

It should be noted that the severity of the condition of patients with asbestosis is mainly due to emphysema and impaired respiratory function and, to a lesser extent, pneumofibrosis. Aggravates the course of the disease with the addition of infection and the development of complications.

Diagnostic principles

A doctor can suspect asbestosis in a patient by carefully studying the anamnesis of his life and illness, comparing it with complaints and objective examination data.

The main method of diagnosis is radiological. However, changes on the radiograph associated with the penetration of asbestos dust into the respiratory tract are present not only in patients with pneumoconiosis. They can also be found in absolutely healthy people who have ever been in contact with this mineral. These may be pleural plaques (thickening or calcification of the parietal pleura) and a small effusion into the pleural cavity. In the absence of complaints and other radiological signs of the disease, such changes are not considered a manifestation of an occupational disease.

If chest x-ray findings are questionable, a high resolution prescription is recommended.

Additional information about the patient's health status is provided by:

• (signs of inflammation);
• (asbestos fibers and bodies);
• (cor pulmonale), etc.

As soon as the presence of an occupational disease is confirmed in a patient, he should be immediately informed about it. After all, within a certain time a person has the right to receive compensation for the damage caused to his health.

Patient management

There is no specific treatment for this pathology, therefore, after making a diagnosis, the patient is advised to stop contact with dust (if it continues) and give up bad habits. In the future, an examination of working capacity is carried out and symptomatic treatment is prescribed. The latter includes:

• the use of expectorants and sputum thinners, as well as bronchodilators;
• inhalations of various therapeutic solutions (essential oils, sodium bicarbonate);
• breathing exercises;
• physiotherapy procedures;
• with infectious complications - taking antibacterial drugs;
• with respiratory failure - oxygen therapy, etc.

Which doctor to contact

If you suspect asbestosis, you should contact a pulmonologist. It must be remembered that the disease can occur even many years after minor contact with asbestos. A consultation with an oncologist and a cardiologist is mandatory. The treatment involves a specialist in exercise therapy, a physiotherapist, an infectious disease specialist.

Asbestosis – Lung diseases associated with asbestos exposure are caused by inhalation of asbestos fibers. Diseases include asbestosis; lung cancer; the formation of benign focal lesions of the pleura and its thickening; benign pleural effusions and malignant pleural mesothelioma. Asbestosis and mesothelioma lead to progressive shortness of breath.

Diagnosis is based on history and chest x-ray or CT and, in the case of malignancy, tissue biopsy. Treatment of asbestosis is effective, except for malignant neoplasms, which may require surgical and/or chemotherapy treatment.

ICD-10 code

J61 Pneumoconiosis due to asbestos and other minerals

What causes asbestosis?

Asbestos is a naturally occurring silicate whose heat-resistant and structural properties have made it useful in construction and shipbuilding, it is used in automobile brakes and some textile industries. Chrysotile (snake fibre), chrocidotil and amosite (amphibole, or straight fibers) are the 3 main types of asbestos fibers that cause disease. Asbestos can affect the lungs and/or pleura.

Asbestosis, a form of interstitial pulmonary fibrosis, is much more common than malignant diseases. Shipbuilders, construction workers and textile workers, home remodelers and workers, workers and miners who are exposed to asbestos fibers are numerous categories of people at risk of the disease. Secondary lesions may occur among family members of sick workers and among those who live close to mines. The pathophysiology is similar to that of other pneumoconiosis - alveolar macrophages, in an attempt to engulf inhaled fibers, secrete cytokines and growth factors that stimulate inflammation, collagen deposition, and ultimately fibrosis, except that asbestos fibers themselves can also be directly toxic to lung tissue. Disease risk is usually associated with the duration and intensity of contact and the type, length and thickness of inhaled fibers.

Symptoms of asbestosis

Asbestosis is initially asymptomatic, that is, when there are no symptoms of asbestosis, but can cause progressive shortness of breath, a nonproductive cough, and malaise; the disease progresses in more than 10% of patients after cessation of contact. Long-term asbestosis can cause thickening of the terminal phalanges of the fingers, dry basilar rales, and, in severe cases, symptoms and manifestations of right ventricular failure (cor pulmonale).

Pleural lesions - a hallmark of asbestos damage - include the formation of pleural deposits, calcification, thickening, adhesions, effusion, and mesothelioma. Pleural lesions are accompanied by effusion and malignancy, but few symptoms. All pleural changes are diagnosed by chest x-ray or HRCT, although chest CT is more sensitive than x-ray for detecting pleural lesions. Treatment is rarely required except in cases of malignant mesothelioma.

Discrete deposits, which occur in 60% of asbestos-exposed workers, typically involve the parietal pleura bilaterally at the level between the fifth and ninth ribs adjacent to the diaphragm. Spot calcification is common and can lead to misdiagnosis of severe lung involvement if radiographically superimposed on lung fields. HRCT can distinguish between pleural and parenchymal lesions in such cases.

Diffuse thickening occurs in both the visceral and parietal pleura. This may be a spread of pulmonary fibrosis from the parenchyma to the pleura or a nonspecific reaction to a pleural effusion. With or without calcification, pleural thickening can cause restrictive disorders. Rounded atelectasis is a manifestation of pleural thickening, in which invagination of the pleura into the parenchyma can draw lung tissue into a "trap", causing atelectasis. On chest x-ray and CT, it is typically defined as an irregularly contoured scar mass, often in the lower lung, and may be mistaken radiologically for a lung malignancy.

Pleural effusion also occurs but is less common than the other pleural lesions it accompanies. The effusion is an exudate, often hemorrhagic, and usually resolves spontaneously.

Diagnosis of asbestosis

The diagnosis of asbestosis is based on a history of asbestos exposure and a CT scan or chest x-ray. Chest x-ray reveals linear reticular or patchy infiltrates reflecting fibrosis, usually in the peripheral lower lobes, often accompanied by pleural involvement. "Honeycombed lung" reflects more advanced disease, which may involve the middle lung fields. As with silicosis, severity is determined by the International Labor Organization scale, based on the size, shape, location, and severity of infiltrates. Unlike silicosis, asbestosis causes reticular changes mainly in the lower lobes. Root and mediastinal adenopathy is uncommon and suggests a different diagnosis. Chest X-ray is not informative; High resolution chest CT (HRCT) is informative when asbestosis is suspected. HRCT is also superior to chest x-ray in identifying pleural lesions. Pulmonary function tests, which can reveal reduced lung volumes, are non-diagnostic but help characterize changes in lung function long after the diagnosis is made. Bronchoalveolar lavage or lung biopsy is indicated only when atraumatic methods fail to establish a definitive diagnosis; the detection of asbestos fibers indicates asbestosis in people with pulmonary fibrosis, although such fibers can sometimes be found in the lungs of exposed people without the disease.

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asbestosis is a disease of the respiratory system caused by the inhalation of asbestos particles.

Prolonged exposure to these particles in the lungs can lead to scarring of lung tissue and shortness of breath.

Signs of asbestosis can range from mild shortness of breath to very severe lung damage, and they usually occur after several years of regular asbestos inhalation.

Asbestos is a natural substance that is very resistant to temperature and corrosion. In the past, asbestos has been extensively used for the production of insulating and refractory materials, cement, and some types of tiles.

Most people acquired asbestosis from working with building materials. Asbestos is still used in construction in a number of countries. But after studying this disease in the same USA in the mid-70s, the government began to strictly regulate the use of asbestos. Acquired asbestosis among non-asbestos workers is very rare. Treatment of the disease focuses only on relieving the symptoms.

Causes of asbestosis

As the disease progresses, the lungs become more and more scarred, losing their function. Over time, due to asbestosis, the lungs cease to expand normally, severe shortness of breath occurs.

Smoking cigarettes increases the harmful effect of asbestos on the lungs, so smokers develop the disease more often and progress faster.

Risk factors for asbestosis

For example:

asbestos miners.
. Auto mechanics.
. Builders.
. Electricians.
. Dock workers.
. boiler operators.
. Railway workers, etc.

In general, it is safe to be surrounded by asbestos materials as long as they are isolated and do not release particles into the air.

Symptoms of asbestosis

Asbestosis symptoms include:

Dyspnea. It is the main symptom of this disease. At first, shortness of breath is felt only during strenuous work, but over time it can occur even at rest.
. Cough and chest pain. As the disease progresses, a person may experience persistent coughing and chest pains.
. Finger deformity. Severe cases of asbestosis sometimes result in a deformity in which the fingers become drumstick-like (rounded fingertips). It should be remembered that many other diseases cause similar changes.

When should you see a doctor?

Diagnosis of asbestosis

To identify asbestosis, a number of studies may be needed:

Chest x-ray. Asbestosis appears on x-ray as wide light areas in the lungs. In severe asbestosis, the entire lung can be affected, causing it to look like a honeycomb.
. Computed tomography (CT). This is a computer scan of the chest using X-rays, which makes it possible to examine tissues in detail. CT helps diagnose asbestosis in its early stages, before lung lesions become visible on plain x-rays.
. Determination of lung function. These tests are to determine how much air the patient's lungs can take in. The patient, for example, may be asked to exhale as hard as possible into a special device called a spirometer. Other tests will show the oxygen saturation of the blood (oximetry). Based on the results of the examination, the doctor will conclude how badly the lungs are affected.

Asbestosis treatment

Therefore, treatment is focused only on relieving the symptoms of the disease:

. Medical treatment. People with asbestosis may benefit from inhalers given to people with asthma. They contain bronchodilators - substances that dilate the bronchi and improve breathing. These include Ventolin, Salamol, Serevent and others.
. Non-drug treatment. To facilitate breathing, the doctor may prescribe oxygen, which is supplied to the patient through a special plastic mask.
. Surgery. If the lungs of the patient do not cope with their functions, then he may be prescribed a lung transplant. This is a very complex operation, associated with many risks, but sometimes it is the only salvation for the patient.

Quit smoking. Patients need to stop smoking because smoking worsens the course of asbestosis. In addition, smoking is the surest way to get lung cancer, emphysema and many other dangerous diseases.
. Get vaccinated. With impaired lung function, it becomes difficult to treat lung infections, and colds often cause complications. Your doctor may recommend getting vaccinated to avoid the flu and other viral infections.

Complications of asbestosis

Prevention of asbestosis

The main sources of asbestos to avoid are:

Heating mains insulation.
. Some types of tiles.
. Building insulation of old houses.
. Soundproofing of some rooms.
. Some types of building tiles, etc.

Konstantin Mokanov