Analysis Of Occupational Exposure To PM2.5 During Bronchoscopic Thermal Ablation

ObjectiveTo measure the mass concentration of PM2.5 in the smoke generated by thermal ablation such as laser and high-frequency electric in real time during bronchoscopic procedure,leading to investigate the occupational exposure of PM2.5 in smoke from thermal ablation under flexible bronchoscope and discuss the effects of different thermal ablation techniques,operating methods and human factors on the exposure of PM2.5 to medical staff.MethodThe indoor air samples before and during the operation of bronchoscopy were collected from three endoscopy rooms in Center of Interventional Pulmonology of Changhai Hospital from September 12,2018 to October 24,2018.The real-time relationship curve of PM2.5 concentration was recorded.The bronchoscopic laser and high frequency electric therapy were the mainly monitoring objects.The patients are anesthetized by local anesthesia combined with intravenous anesthesia.The trend and difference of PM2.5 exposure concentration with time under different thermal ablation was studied,while the influence and effect of negative pressure suction on PM2.5concentration and the influence of human factors on PM2.5 exposure under thermal ablation were analyzed.Nonparametric tests was used to compare the concentration of PM2.5 in two groups of independent samples with non-normal distribution under different thermal ablation.Results1.Comparing laser ablation,electrocision and electrocoagulation,the concentration of PM2.5 within 60 seconds in the environment after a short time of laser,electrocision or electrocoagulation treatment increased temporarily after a certain delay,and eventually remained the same as the background concentration.However,the concentration of PM2.5 did not change significantly after a short time of electrocoagulation.Under the current environmental conditions in study,the maximum ambient concentration of PM2.5 after laser irradiation could reach 700.9?g/m~3,the average concentration was 187.30?g/m~3;the peak concentration of PM2.5 produced by electrocautery is 210.1?g/m~3,the average concentration is 74.73?g/m~3;the peak concentration of PM2.5 produced by electrocoagulation is 43.6?g/m~3,the average concentration is 42.34?g/m~3.The concentration of PM2.5 produced by laser ablation was averagely higher than that by electrocoagulation and electrocoagulation,and the difference was statistically significant.In high frequency electrothermal ablation,the average concentration of PM2.5 produced by electrocision was higher than that by electrocoagulation,and the difference was statistically significant.There was no significant increase in PM2.5 concentration caused by electrocoagulation.2.In our research,one bronchoscopic laser therapy was studied,in which the average exposure concentration of PM2.5 was 46.7 ug/m~3,which was statistically higher than the background concentration 36.0 ug/m~3.The total procedure duration was 45minutes and the effective laser irradiation time was 65 seconds.Another bronchoscopic procedure with electrocautery snare and electrocoagulation was monitored,in which the background concentration of PM2.5 was 60.2 ug/m~3 before operation,the treatment time was 38 minutes,the effective high-frequency electric cauterization time was 125 seconds.Finally the average exposure concentration of PM2.5 was 79.2 ug/m~3,which was statistically higher than the background concentration.3.The operation places of all 19 cases of bronchoscopy in this study were recorded,and their correlation with the increase of PM2.5 concentration during the bronchoscopy was analyzed.The results showed that the changes of the operation places had little effect on PM2.5 occupational exposure.4.Under the same external environment,the time-dependent curves of PM2.5concentration within 60 seconds after single laser irradiation were recorded with negative pressure suction on and off respectively,and then compared with those of general bronchoscopy.The monitoring results showed that PM2.5 concentration increased temporarily after laser irradiation,nevertheless PM2.5 concentration was higher without negative pressure suction.Negative pressure suction could reduce PM2.5 exposure by70-80%.For general bronchoscopy,negative pressure suction had no statistically significant effect on PM2.5 exposure.5.When two different operators performed laser therapy under the same external conditions,the duration from the time when the focus was irradiated to the time when the PM2.5 concentration reached a peak after each of laser irradiation was used as an indicator of the difference of PM2.5 exposure to human factors.The results showed that the average duration of operator A was 45.38±13.80s and that of operator B was37.88±9.31s.There was no significant difference in the average duration between the two groups statistically.There was no significant difference in the effect of different operators on occupational exposure to PM2.5 during thermal ablation.ConclusionThrough quantitative analysis of PM2.5 exposure and related factors in smoke generated by different thermal ablation techniques under fiberoptic bronchoscope,it was found that thermal ablation operation could cause transient elevation of PM2.5concentration in the environment and increase the overall PM2.5 exposure concentration during bronchoscope operation.The PM2.5 exposure of medical staff during operation could exceed the lower limit of mild PM2.5 pollution stipulated by the state.In the long run,it may endanger the health of medical staff.The concentration of PM2.5 exposure produced by laser therapy is higher than that produced by high frequency electricity.High frequency electrocautery produces more PM2.5 than electrocoagulation.Electrocoagulation hardly causes PM2.5 occupational exposure.The apply of negative pressure suction device during operation is the key to reduce PM2.5 exposure of medical staff in thermal ablation,while human factors have little influence on PM2.5 occupational exposure.As a basic research on occupational protection of smoke in interventional pulmonology,this study lays a foundation for further research on the harm of PM2.5 to medical staff,and the exploration of protective measures and the development of relevant guidelines.