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Airborne particulate matter may induce health risk with inhalation. Special concerns exist for deployed military personnel with inhaled particulate matter in desert environments. Continuous positive airway pressure (CPAP) used in obstructive sleep apnea may facilitate inhalation of particulate matter. We evaluated the ability of commercial CPAP filter systems to eliminate inhalation of particulate matter.

An ultrasonic medical nebulizer (DeVilbliss Ultraneb, DeVilbliss, Somerset, PA) atomized liquid producing "respirable" aerosol. Technetium-99m diethylene triamine pentaacetic acid dissolved in water was also aerosolized to quantify aerosol inhalation. A high efficiency particulate air (HEPA) filter placed at the patient-hose connection port in the bilevel positive airway pressure (BPAP) device captured the aerosol inbound to the patient. The HEPA filter provided a means to quantify aerosol dose delivered to a simulated patient. Commercial foam and ultrafine filters were assessed with aerosol to determine the simulated patient exposure.

Foam and ultrafine filters used together allowed 1.5% or less of aerosol volume to pass through the BPAP system. Foam filters alone allowed an average of 18.9% of aerosol delivered to pass through the BPAP system.

Foam and ultrafine filters used together in BPAP systems provide excellent aerosol filtration in this laboratory simulation of BPAP use.