The purpose of this project is to study the composition, hazard, and protection of smoke from endoscopic gastrointestinal surgery. The study is a single-center, prospective, randomized, controlled, cohort study. The investigators plan to enroll 80 patients who undergo endoscopic gastrointestinal surgery and 10 medical staff participating in surgery in the gastrointestinal endoscopy room of the First Affiliated Hospital of Xi'an Jiao Tong University. The investigators will randomize the included study subjects. The investigators will monitore smoke and try to remove the smoke with an air sterilizer in the Air sterilizer group. The control group was monitored for smoke without any intervention. The primary endpoint is concentration of PM2.5 in smoke from endoscopic gastrointestinal surgery, the risk factors, and the effect of air sterilizer on its removal. The secondary endpoint is the concentration of PM1.0, PM10, formaldehyde, Total Volatile Organic Compounds, CO, and CO2 in smoke from endoscopic gastrointestinal surgery, the risk factors, and the effect of air sterilizer on its removal. Other exploratory objectives include the hazards of smoke to staff in the gastrointestinal endoscopy room, and the viral content of smoke.

The investigators will enroll 80 patients undergo endoscopic gastrointestinal surgery and 10 medical staff participate in surgery in the gastrointestinal endoscopy room. The patients will be randomized into the control group and the Air sterilizer group. The investigators will use air quality testing equipment to monitor the concentrations of the PM2.5, PM1.0, PM10, formaldehyde, Total Volatile Organic Compounds, CO, and CO2 of the smoke near the mouth and nose of the surgeon, cooperating nurse, and anesthesiologist, and try to remove the smoke with an air sterilizer in the Air sterilizer group. The control group was monitored for concentrations of the above ingredients in smoke without any intervention. The primary endpoint is concentration of PM2.5 in smoke during endoscopic gastrointestinal surgery, the risk factors related to surgery, and the effect of air sterilizer on its removal. The secondary endpoint is the concentration of PM1.0, PM10, formaldehyde, Total Volatile Organic Compounds, CO, and CO2 in smoke during endoscopic gastrointestinal surgery, the risk factors related to surgery, and the effect of air sterilizer on their removal. Other exploratory objectives include the hazards of smoke to staff in the gastrointestinal endoscopy room, and the viral quantitative of smoke.

Inclusion Criteria:

• Patients who undergo endoscopic gastrointestinal surgery and medical staff who participate in the surgery in the gastrointestinal endoscopy operating room of the First Affiliated Hospital of Xi'an Jiao Tong University
• Voluntary participation in this study

Exclusion Criteria:

• Severe liver disease
• Severe Kidney disease
• Severe cardiovascular disease
• Severe cerebrovascular disease
• Severe neuropsychiatric disease
• Unable to cooperate with the research

The invesitigators will conduct further research on endoscopic surgical smoke