Humans have been using masks to prevent dust for hundreds of years. Earlier, artisans who worked in workshops such as mining, smelting or smelting knew that some dust or smoke was toxic and long-term inhalation would make people sick. At work, they often cover their faces with cloth to reduce the inhalation of toxic dust. By the end of 18, some people began to design dust masks. The simple mask shown in figure 1 was designed by a mining engineer in Prussia. Lewis P. Haslett was the first patent holder of dust mask in the United States, and the mask he invented was also used by miners. Since then, a series of patents for respiratory protective articles have appeared in Europe and America, using cotton fiber, activated carbon, lime and other filtering materials to filter dust and some toxic and harmful gases. Modern dust masks are all made of non-woven fabrics, which originated from America 1960s~ 1970s. Based on the proprietary technology of non-woven fabrics and electrostatic fiber cotton filtration, American 3M Company began to design and produce dust masks from 1967, which coincided with the promulgation of the American Occupational Safety and Health Act (1970) and the establishment of the American Occupational Safety and Health Administration (OSHA). The occupational health and protection of American workers have been comprehensively strengthened, which has effectively promoted the application of dust masks and the research and development of more new technologies. After more than 40 years of development,

Doctors wear masks for a long time. French surgeon Paul Berger (1845- 1908) was the first person in the medical field to design and use masks (Figure 2). He was inspired by German pathologist CarlFluegge who found that saliva contained pathogenic bacteria. He suspected that saliva drops produced by doctors and assistants during the operation were one of the causes of wound infection. So he cut six layers of gauze into squares to make a mask, sewed the lower part of the mask on the surgical gown to cover his beard, and tied the upper part behind his neck with a rope to cover his nose. Berger began to use this mask in surgery from 1897 to 10. In the following 15 months, Berger found that the probability of infection in his surgical patients decreased significantly. 1899 On February 22nd, Berger read a paper entitled "Using masks in surgery" at the meeting of surgical association held in Paris, which made him