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06:57
Effects of Surgical Masks on Cardiopulmonary Function in Healthy Subjects
Published on: February 12, 2021
Quantifying exposure risk: surgical masks and respirators
Keith T Diaz1, Gerald C Smaldone
1Stony Brook University Medical Center, State University of New York, Stony Brook, NY, USA. keith.diaz@sunysb.edu
American Journal of Infection Control
|August 26, 2010
Summary
Wearing masks at the source of respiratory aerosols, particularly N95 respirators, significantly reduces particle exposure for receivers in ventilated areas. Mask filtration alone, whether at the source or receiver, showed minimal protection without a proper seal.
Area of Science:
- Environmental Health
- Infectious Disease Transmission
- Occupational Safety
Background:
- The transmission dynamics of respiratory infectious aerosols between a source and receiver remain under-investigated.
- Previous research has not extensively evaluated the protective effects of masks in mitigating aerosol transmission.
Purpose of the Study:
- To investigate the efficacy of masks in reducing respiratory infectious aerosol transmission.
- To compare the protective effects of masks worn at the source versus the receiver.
Main Methods:
- A bench model was developed using radiolabeled wet aerosols to simulate exhaled particles.
- Two types of masks (N95 respirator and surgical mask) were tested on a ventilated mannequin head (source) and a receiver mannequin head.
- Exposure was quantified by measuring particles on a receiver filter, with results presented as simulated workplace protection factor (sWPF).
Main Results:
- Masks worn at the source significantly reduced receiver exposure (sWPF 170-320) in ventilated conditions, primarily through deflection.
- Masks worn at the receiver (filtration) offered minimal protection (sWPF 1.37-2.21) unless a Vaseline seal was applied (sWPF 118).
- In non-ventilated conditions, only a Vaseline seal provided significant protection (sWPF 16-101).
Conclusions:
- Deflection of exhaled aerosols by wearing a mask at the source is highly effective in ventilated environments.
- Mask filtration, without a proper seal, plays a minor role in reducing aerosol exposure at either the source or receiver.
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