Anthracosis is a lung lesion caused by inhalation of coal dust particles and characterized by the development of pulmonary fibrosis. Symptoms of anthracosis (cough, shortness of breath, chest pain, fatigue) are progressive. When making a diagnosis, professional anamnesis, data from radiography and computed tomography of the lungs, spirometry, analysis of blood gas composition are taken into account. Treatment of anthracosis is mainly symptomatic: taking bronchodilators, steroid medications, chest massage, oxygen therapy. Patients with anthracosis are shown to be monitored by a pulmonologist and a professional pathologist; in some cases, a change of profession.
J60 Coal miner ‘s pneumoconiosis
Anthracosis is a pneumoconiosis that develops with prolonged exposure to coal dust on the lung tissue. Lung lesions caused by inhalation of carbon-containing dust (carboconiosis) include anthracosis, graphitosis and sooty pneumoconiosis. Among them, anthracosis is the most common occupational disease. It develops among workers engaged in coal mining and having a long production experience. Depending on the working conditions and the duration of contact with coal dust, the prevalence of anthracosis among miners ranges from 12 to 50%. The progression of anthracosis can lead to severe lung lesions, the development of cardiopulmonary insufficiency, disability, which determines its medical and social significance for occupational pathology and pulmonology.
The main mechanisms determining the risk of developing coal pneumoconiosis include: the concentration of coal dust in the ambient air, the length of service of industrial harmfulness, as well as the presence of predisposing factors. Anthracosis usually affects miners, workers of mining and processing plants and coke plants who have worked in the coal industry for at least 15-20 years. More often and earlier, clinical and radiological changes develop in persons associated with the extraction of anthracite, less often – rocks with a lower degree of coalification (stone, brown coal). Along with anthracosis, coal industry workers may encounter other pneumoconioses, primarily silicosis or anthracosilicosis, because coal mine dust often has an admixture of silicon dioxide. Additional factors that increase the risk of developing anthracosis are concomitant smoking, non-compliance with labor protection requirements, violation of the technological process of coal mining, chronic respiratory diseases, etc.
The smallest particles of coal dust enter the body by inhalation. A certain part of them settles on the mucous membranes of the nasopharynx, trachea and bronchi and with the help of movements of the cilia of the ciliated epithelium and the resulting mucus is removed outside. At high concentration and intense exposure, dust particles penetrate into the lower respiratory tract, where they are found in the lumen of the alveoli, macrophages and cells of the alveolar epithelium. With the lymph current, coal particles can be transferred to regional (bronchial, tracheal, bifurcation) and other lymph glands. With anthracosis, the surface of the lung acquires a characteristic mottled appearance and a gray-black color. Constant irritation of the bronchi with coal dust causes the development of chronic catarrhal bronchitis, and the deposition of coal masses in the interstitial tissue causes desquamative interstitial pneumonia with subsequent outcome in lung cirrhosis.
Based on pathomorphological and clinical-radiological changes in the lung tissue, 2 forms of coal pneumoconiosis are distinguished: spotted anthracosis (benign anthracous fibrosis) and progressive massive pulmonary fibrosis. The course of spotted anthracosis is slowly progressive and relatively favorable. In the lungs there are single local foci of coal pigmentation in the form of “anthracite spots”. Pulmonary fibrosis is poorly expressed; however, due to ectasia of terminal bronchioles, local centrilobular emphysema develops. A variety of this form is a knotty spotted anthracosis, in which radiologically nodules up to 1 cm in size are determined in the lung tissue.
Progressive massive pulmonary fibrosis usually develops in patients with intercurrent complications (for example, pulmonary tuberculosis). In the etiology of this form of anthracosis, the role of the immunocomplex mechanism of lung tissue damage is not excluded – the proof of this is the frequent combination of coal pneumoconiosis and rheumatoid arthritis, called Kaplan and Coline syndrome. Progressive massive fibrosis has an unfavorable course; at the end of this form of anthracosis, the structure of lung tissue changes according to the type of “honeycomb” (so-called “cellular lung”), the pulmonary heart is formed. The cause of death of patients, as a rule, becomes cardiopulmonary insufficiency.
Features of the clinical course of anthracosis are determined by the severity of bronchitis, emphysema and pulmonary fibrosis. Based on the clinical and radiological picture, three stages are distinguished in the development of pneumoconiosis of coal miners.
In stage I, symptoms may be absent or may be represented by rapid fatigue, cough, shortness of breath with physical exertion and chest pain. According to radiography data, small focal shadows with a diameter of 1 to 3-5 mm are determined in the middle sections of the lungs; the roots of the lungs are expanded; the pulmonary pattern is deformed.
For stage II of anthracosis, shortness of breath at rest, an increase in general weakness, the persistence of cough and thoracalgia are typical. Radiological changes include an increase in the number and size of small focal shadows, pronounced emphysema, thickening of the pleura.
Stage III of anthracosis proceeds with pronounced signs of respiratory failure. With progressive massive fibrosis, melanophthysis can be observed – the coughing up of black sputum caused by the breakthrough of fibrous cavities into the respiratory tract. Severe complications of the progressive form of anthracosis are pulmonary hypertension with right ventricular insufficiency. On the radiographs of the lungs, individual massive darkenings of up to 5-10 cm in size are determined against the background of multiple small-focal formations and the phenomenon of “honeycomb”. Sometimes anthracotic caverns are visible in the center of large shadows.
Patients with anthracosis and other carboconioses are at risk for the development of respiratory tuberculosis. Pulmonary anthracosis can be combined with anthracosis of the skin – the deposition of coal particles in the dermis.
To correctly determine the form of pneumoconiosis, a thorough collection of professional anamnesis is necessary. In favor of anthracosis, an indication of prolonged contact with coal dust indicates. Physical examination reveals a barrel-shaped chest, weakening of breathing, dulling of percussion sound. The primary stage of instrumental diagnostics includes chest x-ray, however, additional lung CT is required to clarify the genesis of focal shadows.
Spirometry allows us to judge the degree of violation of the function of external respiration, and the study of the gas composition of the blood – the severity of respiratory failure. Often, bronchoscopy with a transbronchial biopsy of lung tissue is required to exclude other lung pathology.
When establishing the diagnosis of anthracosis, first of all, it is necessary to exclude the patient’s contact with a harmful agent – coal dust. The issue of transferring the patient to a less dusty area of work (at stage I), changing professional activities or assigning disability (at stage II and III) is being resolved. In addition, patients are advised to avoid contact with any dust, beware of viral infections, limit physical activity, and give up smoking. Specific treatment of anthracosis has not been developed, therapy is symptomatic. Depending on the stage of anthracosis and the severity of clinical manifestations, bronchodilators, steroid drugs, vitamin therapy are prescribed. Of the physiotherapeutic techniques, inhalation therapy, percussion chest massage are effective. With pronounced signs of respiratory insufficiency, oxygen therapy is indicated.
Prognosis and prevention
Anthracosis is a slowly progressing disease, but its late detection or addition of complications predetermine an unfavorable outcome. Spotted anthracosis has a more favorable course compared to progressive massive fibrosis. At stage I of anthracosis, patients remain functional; at stage II and III, the prognosis for working capacity is questionable. Patients with anthracosis should be under the careful supervision of a pulmonologist and a occupational pathologist; if necessary, consult a phthisiologist. Prevention of coal pneumoconiosis consists of carrying out engineering and technical measures aimed at reducing the release of dust during tunneling, minimizing the contact of workers with coal dust, the use of personal protective equipment (respirators). Persons exposed to carbon-containing dust should undergo periodic medical examinations.
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