Can the gas emitted during welding poison people? What are the symptoms?

Welding fume is liquid metal and slag that are overheated and evaporated at the high temperature of arc welding. As soon as this high-temperature steam leaves the high-temperature zone of arc welding, it is quickly oxidized and condensed into fine solid dispersed particles or fine solid agglomerated particles, which are suspended in the air and become welding smoke. The amount of welding dust produced by several common welding methods is listed in table 1. The nature, composition, morphology and chemical structure of welding dust of various welding materials are comprehensively and deeply explained in the book "Welding Hygiene and Safety" compiled by the Eighth Committee of the Welding Society, so I won't repeat them here. In the past, the harm degree of welding dust was controversial. By the 1980s, due to the rising incidence of welders in some units, it was confirmed that long-term inhalation of welding dust such as Jie 422 and Jie 507 covered electrode would affect human respiration through the investigation of the incidence, clinical research and animal tests, especially the autopsy analysis of welders who died of welder's pneumoconiosis, and the cooperation of Dalian Shipyard, Jiangnan Shipyard, Gansu Provincial Health and Epidemic Prevention Station, Ministry of Railways Labor and Health Research Institute and Qiqihar Vehicle Factory. Therefore,1October 5th, 1987 165438 The Ministry of Health, the Ministry of Labor and Personnel, the Ministry of Finance and the All-China Federation of Trade Unions jointly issued the Provisions on Revising the Scope of Occupational Diseases and the Treatment Methods for Occupational Disease Patients, which officially designated "welder pneumoconiosis" as an occupational disease. The conscious symptoms of welder's pneumoconiosis are cough, black sputum, chest tightness and shortness of breath, and decreased vital capacity. X-ray chest film of welder's pneumoconiosis shows irregular or circular shadows. The length of service of welder pneumoconiosis is about 15~20 years. Because there were many welders entering the factory in China in the 1950s, the late 1970s and 1980s were the periods of high incidence of welder pneumoconiosis. More than 3,000 welders were inspected from 1975 to 1977, and it was confirmed that welder's pneumoconiosis accounted for 3.69%. After 20 years' dynamic observation in Dalian Shipyard from 65438 to 0983, 10.63% of 743 welders were diagnosed as welder's pneumoconiosis. A total of1987,660 workers in the freight car workshop of Qiqihar Vehicle Factory were examined, and it was confirmed that 13. 18% of them suffered from welder's pneumoconiosis. In the investigation of the incidence of welder's pneumoconiosis in 1980s, it was also found that the incidence was higher in the cold area in the north and lower in the south. This is because when the weather is cold in the north, the doors and windows of the workshop are closed for a long time, and the natural ventilation conditions are poor. Therefore, the northern welding workplaces should pay more attention to protection.