Silicosis is the most serious type of pneumoconiosis, which is caused by long-term inhalation of dust containing free silica. Extensive nodular fibrosis in the lung seriously affects lung function and loses the ability to work.
The cause of disease
Silicon is widely distributed in nature, and about 95% of it is pure time in various forms (containing more than 97% free silica). Silicon is also the main component of the earth's crust. Therefore, when mining, quarrying and tunneling, workers are engaged in rock drilling and blasting. Have more opportunities to contact with dust; Stone rolling, crushing and mixing in the manufacture of glass, enamel and refractory materials, sand grinding, sand mixing, modeling, furnace building, sand blasting and sand cleaning in the foundry industry. , have access to silica dust (commonly known as silica dust). Free silica is usually represented by time.
The contact time depends on many factors. In addition to its physical and chemical characteristics, the content of free silica in dust, the concentration of dust in the air, the particle size of dust, contact time and the body's defense function all affect the occurrence and severity of silicosis. Generally speaking, dust containing more than 80% free silica often causes typical diffuse collagen fiber changes in the lungs, and the disease progresses rapidly and is prone to fusion. When the free silica content is lower than 80%, the lesion is atypical and the disease progresses slowly. When it is lower than 10%, it mainly causes interstitial fiber changes and develops slowly, which is classified as other pneumoconiosis.
A large amount of dust with high content of free silica is inhaled into the lungs, which often cannot be completely removed from the respiratory tract in time. Sometimes, although there are no signs of silicosis, silicosis reappears several years after leaving work. This situation is usually called "advanced silicosis"; Early silicosis patients will continue to develop even if they leave dust work. If there are no complications, patients can survive for a long time, but they often lose their ability to work. Therefore, in order to protect workers' health, China stipulates that the maximum allowable concentration of dust containing more than free silica 10% in workplace air is 2 mg/m3; When it exceeds 80%, it is 1mg/m3. If this requirement can be met, silicosis will not occur.
In addition, there are chronic diseases of respiratory system, such as chronic rhinitis, chronic bronchitis, emphysema and tuberculosis. Patients have poor defense function and weak airway mucus-cilia activity, which makes them more susceptible to illness than healthy people in the same environment.
Silicosis is the most common type of pneumoconiosis, which is caused by long-term inhalation of a large number of dust containing free silica, mainly a disease of extensive nodular fibrosis of the lungs. In severe cases, it affects respiratory function and loses the ability to work.
Generally, there are no symptoms or symptoms are not obvious in the early stage. As the disease progresses, the symptoms will get worse. Because the inhalation of silica dust stimulates the respiratory tract and causes reflex cough, the degree of cough and sputum volume are closely related to respiratory tract infection, but not to the degree of silicosis. A few patients may have phlegm and blood. In the early stage, I often feel chest tightness and shortness of breath, and acupuncture-like pain unrelated to childbirth often occurs when the climate is changeable. The degree of chest tightness and shortness of breath is related to the scope and nature of the lesion. If the lesion is large and progresses rapidly, shortness of breath is obvious and gradually aggravated. Patients will have dizziness, fatigue, insomnia, palpitation, loss of appetite and other symptoms.
Comprehensive measures should be taken for silicosis patients, including removing dust, arranging proper work, strengthening nutrition and doing moderate rehabilitation exercise, so as to strengthen their physique and prevent respiratory tract infections and complications.
Dust prevention is the key to control or reduce the occurrence of silicosis. Industrial and mining enterprises should adopt comprehensive dust prevention measures such as rushing into production process, wet operation, sealing dust source, ventilation and dust removal, and equipment maintenance and repair. Strengthen personal protection and observe dust-proof operation procedures. Regularly detect the dust concentration in the air of production environment and strengthen publicity and education. Do a good job in pre-job physical examination, especially X-ray chest film. All patients with active pulmonary tuberculosis and various respiratory diseases should not take part in silica dust operations. Strengthen the regular physical examination of workers exposed to silica dust, and the inspection interval depends on the content of exposed silica dust and the concentration of air dust. It is also necessary to strengthen the prevention and treatment of tuberculosis in industrial and mining areas. Those with negative tuberculin test should be vaccinated with BCG; Preventive anti-tuberculosis chemotherapy for positive patients can reduce the occurrence of silicosis and complications.
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