ABSTRACT
SARS-CoV-2 has been detected both in air and on surfaces, but questions remain about the patient-specific and environmental factors affecting virus transmission to the environment. Additionally, more detailed information on viral findings in the air is needed. In this cross-sectional study, we present results from 259 air and 252 surface samples from the surroundings of 23 hospitalized and eight home-treated COVID-19 patients between July 2020 and March 2021 and compare the results between the measured environments and patient factors. In four cases, positive environmental samples were detected even after the patients had developed a neutralizing IgG response. SARS-CoV-2 RNA was detected in multiple particle sizes and different air samplers. Appropriate infection control against airborne and surface transmission routes is needed in both environments, even after antibody production has begun. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.
ABSTRACT
BACKGROUND: COVID-19 and other respiratory infections spread through aerosols produced in respiratory activities and in certain surgical procedures considered as aerosol-generating procedures (AGP). Due to manipulation of the upper airway mucosa, rhinosurgery has been considered a particular risk for spread of respiratory infections. Our aim was to assess staff exposure to aerosols during common rhinosurgical procedures METHODS: Staff exposure to generated particle concentrations and size distributions between 0.3 λm and 10 λm were measured during rhinosurgery using an optical particle sizer without any additional collection methods. Similarly measured aerosol exposure during coughing (a commonly used risk reference for aerosol generation) and the operating roomâ™s background concentration were chosen as reference values. RESULTS: Altogether 16 common rhinological surgeries (septoplasties and endoscopic sinus surgery) were measured. The use of suction produced significantly lower aerosol concentration compared to coughing. Low aerosol generation was observed during injection anaesthesia of the nasal mucosa. Instrument comparison revealed that the microdebrider produced fewer aerosols than cold dissection in particles of 1-5 λm and >5 λm. CONCLUSIONS: Common rhinosurgeries do not seem to generate as high aerosol concentration exposures as previously believed. Rather, the observed aerosol exposure is lower or similar to exposures during coughing. Therefore, the classification of common rhinosurgeries as AGPs should be re-assessed or possibly discarded.