PPE

Occupational health of welding workers needs safety protection

1. Main hazards in welding operation

1. Hazards of metal dust. The composition of welding dust varies with different welding rods. The electrode consists of core and coating. 1n addition to a large amount of iron, there are carbon, manganese, silicon, chromium, nickel, sulfur and phosphorus in the core; The inner material of the drug skin is mainly composed of marble, fluorspar, rutile, pure salt, water glass, ferromanganese, etc. During welding, the arc discharge produces a high temperature of 4000 ℃ to 6000 ℃. While melting the welding rod and weldment, a large amount of dust is produced. The main components are iron oxide (mainly ferric oxide, accounting for 36% – 76%), manganese oxide, silicon dioxide, silicate, fluoride, ozone and nitrogen oxides. The dust particles diffuse in the working environment and are easily inhaled into the lungs. Long term inhalation can cause lung fibrosis, which is called welder’s pneumoconiosis, and often accompanied by manganese poisoning, fluorosis and metal smoke heat. The incidence of pneumoconiosis is slow, mainly manifested as chest tightness, chest pain, shortness of breath, cough, expectoration and other respiratory symptoms, accompanied by headache, weakness and other diseases, but it is very mild, generally does not affect the work. Early lung function damage is not obvious, late lung function may be impaired, when combined with pulmonary infection, symptoms and signs tend to be obvious. The length of service is mostly 7-23 years, with an average of about 20 years. Chest X-ray findings: in the early stage, irregular small shadows were dominant, mainly in the two middle and lower lung areas. There are small round shadows between them, which are widely distributed and low density; Some of them are mainly round like small shadows with high density, and blocky large shadows can be seen in some cases in the late stage. The hilum of lung is generally not enlarged, and there are few pleural adhesions and emphysema. After leaving the job, there was little progress



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