Aluminosis is an occupational disease from the group of pneumoconioses that develops with regular, prolonged inhalation of aluminum vapors or dust. The main signs of aluminosis are progressive shortness of breath, cough. The patient is concerned about pain and heaviness in the chest, symptoms of general intoxication. The diagnosis is established on the basis of X-ray or CT data of the chest organs in the presence of a clear connection of the disease with professional activity. With aluminum pneumoconiosis, conservative therapy is prescribed using bronchodilators, corticosteroids, mucolytics.
J63.0 Aluminosis (lung)
Aluminosis (aluminum lung, bauxite lung, Shaver-Riedel syndrome) belongs to the subgroup of metalloconioses. The disease mainly affects workers engaged in the extraction of aluminum from bauxite ores, the production of abrasive materials and pyrotechnics, aircraft construction. In 1947, American doctors S. Shaver and A. Riedel first described pneumoconiosis as a pulmonary pathology in corundum grinders. According to statistics, aluminum lung is more common in men (68% of all cases) aged over 35 years. About 3% of all patients suffering from aluminosis die. Mortality among sick women is higher (5.3%).
The direct etiological factor of aluminosis is the inhalation of aluminum vapors and fine dust. In most cases, workers who extract aluminum from bauxite by electrolysis are exposed to the harmful effects of vapors. However, due to the additional content of a large amount of silicon in aluminum ore, such workers develop an occupational disease from the mixed effects of two components. The dust formed during the extraction of bauxite ore also contains aluminosilicates.
Aluminosis often occurs in persons working with the powder form of metal, manufacturers of pyrotechnic powder, aluminum paint, artificial abrasives. The causal factor of occupational disease in this case is microparticles of metal dust with sizes from 0.5 to 5 microns. Aluminosis develops on average after 18-30 years from the start of work in harmful conditions. Concomitant pulmonary pathology and hypersensitivity to aluminum contribute to the early (within 6-24 months) occurrence of metalloconiosis.
Microparticles of aluminum dust are able to penetrate deep into the respiratory tract and reach its terminal section. There, the dust is captured by alveolar macrophages. The reaction of the pulmonary interstitium to aluminum particles can proceed by the type of cellular proliferation or with the formation of connective tissue. In the first case, granulomatous process develops, in the second – interstitial fibrosis. Due to the gradual replacement of sections of interstitial connective tissue, the lungs lose elasticity, gas exchange is disrupted, hypoxemia occurs.
Macroscopically normal pulmonary parenchyma alternates with dense gray-black areas of fibrosis. Often, mainly in the basal parts, there are baggy and cylindrical bronchiectasis, subpleural cysts. Histological examination reveals peribronchial and perivascular clusters of macrophages filled with dust. Aluminum microparticles are present in the preserved alveoli.
At the initial stage, aluminosis disguises itself as frequent acute respiratory diseases. The patient is concerned about recurrent laryngitis, tracheitis and bronchitis. Later, a persistent painful dry or unproductive cough, stabbing and pressing chest pains are added. Initially, the pain syndrome is episodic, later thoracalgia becomes permanent and is felt more in the lateral parts of the chest. In the debut of an occupational disease, the bronchial secret departs with difficulty. After the appearance of bronchiectasis, the cough becomes moist with a large amount of yellowish sputum.
The dyspnea that occurs during exacerbations of pneumoconiosis gradually progresses and becomes permanent. At first, the patient experiences difficulty breathing when walking and climbing stairs, then – with the slightest load and at rest. Aluminosis is often accompanied by abdominal pain, digestive disorders. The general condition of the patient suffers – appetite worsens, unmotivated weakness appears, subfebrility, weight decreases.
Aluminosis is often complicated by the development of bronchiectasis. They are a constant source of infection and provoke the occurrence of pneumonia, periodic hemoptysis and sometimes pulmonary bleeding. Due to the rupture of subpleural cysts, spontaneous pneumothorax occurs, which can recur. In rare cases, tuberculosis develops against the background of aluminum lung. If contact with a harmful agent is not stopped in a timely manner, aluminum accumulates in the lungs and causes further sclerosis of interstitial tissue. Respiratory failure is steadily progressing. A chronic pulmonary heart develops, leading to a deep disability of the patient.
If a lung pathology is suspected, a patient working in a harmful production is examined by a professional pathologist. During the survey, the nature of professional harmfulness and work experience in this specialty are clarified. When examined in advanced cases of aluminosis, cyanosis of the lips and nail plates is revealed, with pronounced pulmonary fibrosis – diffuse cyanosis. Chronic oxygen starvation is indicated by deformation of the terminal phalanges of the fingers and nails by the type of drumsticks and watch glasses. The diagnosis is confirmed by:
- Physical examination. Auscultative data depend on the severity of the process, the presence of complications. At an early stage, hard breathing, dry whistling and buzzing wheezes from both sides are heard. When interstitial fibrosis has formed, sonorous crepitating wheezes are attached, localized in the lower parts of the lungs.
- Methods of functional diagnostics. The function of external respiration is disrupted mainly by the restrictive type. The vital capacity and maximum ventilation of the lungs gradually decrease, the residual volume of air increases. The ECG shows signs of overload of the right parts of the heart.
- X-ray studies. According to radiography and CT of the lungs, a deformed mesh lung pattern is revealed. Against its background, spotty shading located in the lower and middle sections of the lungs is visualized from both sides. Shadows can merge and form rounded or linear conglomerates. Emphysematous bulls are determined subpleurally. Bronchiectasis occurs in the basal pulmonary divisions.
- Laboratory tests. They are used as auxiliary diagnostic methods. In a clinical blood test with aluminosis, an increased number of lymphocytes and eosinophils is often found. Determination of the gas composition of the blood helps to clarify the degree of respiratory failure. To exclude pulmonary tuberculosis, sputum examination is prescribed.
In addition to tuberculosis, aluminosis should be differentiated with lung sarcoidosis, idiopathic fibrosing alveolitis, oncological processes. Differential diagnosis is performed by a pulmonologist. In unclear cases, magnetic resonance and positron emission tomography of the thoracic cavity are performed, bronchoscopy with a transbronchial lung biopsy is prescribed.
Patients with a confirmed diagnosis are strongly recommended to change their type of work. Aluminum has a cumulative property. With the continuation of its effect on the patient’s body, aluminosis steadily progresses. Even after the cessation of contact with the harmful factor, the disease does not undergo reverse development. The main tasks of specialists in the field of pulmonology and occupational pathology are to slow down the course of pneumoconiosis and prevent the occurrence of complications.
Patients are recommended a high-calorie diet, physical therapy, massage, seasonal vaccination against influenza. In case of infectious exacerbations, antibiotics are prescribed taking into account the sensitivity of the sputum microflora. Bronchodilators and mucolytics are used to improve the drainage function of the bronchi. Inhaled and systemic corticosteroids are prescribed for anti-inflammatory and immunosuppressive purposes. In decompensated pulmonary heart failure, cardiac glycosides, calcium antagonists, diuretics are used.
Prognosis and prevention
Aluminosis is incurable, the prognosis for recovery is unfavorable. But the disease usually progresses slowly. After the elimination of professional harmfulness, with the right treatment, the patient can lead an active lifestyle for many years. In severe cases, complex transplantation of donor hearts and lungs is possible. In order to prevent aluminosis, it is necessary to observe safety regulations at the workplace and use personal protective equipment.