No participants were enrolled due to unavailability of research staff.

There are two purposes of this study. The first purpose is to determine the exposure seen by medical providers (e.g. anesthesiologists, surgeons, and nurses) to infectious and smoke particulates generated during anesthesia-related aerosol generating medical procedures (AGMPs) and pediatric otolaryngologic surgeries (with and without an intubated airway). The second goal of this study is to apply a local exhaust ventilation system (LEVS) to re-evaluate the exposure seen by the same medical providers during the same AGMPs and surgeries.

Prior to the patient entering the OR, particle counters (Digital PM2.5 Air Quality detector, ExGizmo, China) will ensure that the OR air quality has undergone the appropriate airflow exchanges and thus will all read 0.

Measurements will be taken every 30 seconds. A research assistant in the periphery of the OR will observe and record the following events: patient entrance into the OR, initiation of mask induction, intubation, rotation of OR table for surgery, initiation of surgery, completion of surgery, rotation of OR back to anesthesia, extubation, and patient departure from the OR. The particle counters will be positioned accordingly: 1) at the level of the patient's head, 2) at the level of the anesthesiologist/surgeon performing the AGMPs, 3) to the right of the patient, 4) to the left of the patient, 5) at the anesthesia workstation, and 6) at the circulating nurse's computer in the corner of the room. The particle counters will continue with measurements until the patient exits the OR. For patients randomized to the LEVS group, active suction will be provided through the use of a closed biohazardous smoke evacuation system (Neptune 3, Stryker, Michigan, USA) equipped with an internal high efficiency particulate air (HEPA) filter capable of capturing aerosolized particles as small as 0.1 mm with 99.99% efficiency via suction power up to 25 cubic feet per minute air exchange. The active suction will be positioned near the patient's airway without interfering with the AGMP, and across from the location of the anesthesiologist or surgeon performing the AGMP such that no HCW is positioned between the patient's airway and the suction device.

Inclusion Criteria:

• children receiving anesthesia-related aerosol generating medical procedures

Exclusion Criteria:

• patients with positive COVID symptoms
• positive preoperative COVID testing