Smoke is a very small solid particle suspended in the air by melting and condensing after high temperature melting and gasification of metal or plastic, often less than 1 micron, commonly used in welding, casting and other operations, the composition of welding smoke is often a variety of metal oxides. The smoke generated by welding contains some suspended particles, toxic gases such as ozone, etc., and some metal suspended particles, which reach the alveoli through the bronchi and can cause diseases such as bronchitis, pulmonary edema and even pneumoconiosis.