ABSTRACT
The chapter provides in-depth information on the materials, design, and production of face masks globally used to protect against SARS-CoV-2 and other respiratory infections. The history of the face masks application is presented. The differences between face masks and respirators as personal protective equipment are analyzed. The advanced materials and technologies for improved antiviral protection are presented. The safety and performance testing procedures and standards are summarized. The influence of face masks on the wearer's comfort is also discussed. © 2023 Elsevier Ltd. All rights reserved.
ABSTRACT
Respiratory infections have arisen as a public health concern. The regulation of COVID-19 is based on knowledge of its transmission mechanism. Masks and respirators act as a physical barrier against respiratory droplets that enter through the nose and mouth, as well as droplets spat by sick persons. Textile masks (including 'do-it-yourself'), surgical (medical) masks and respirators are the three basic types of personal protection devices, covering the human face. The purpose of our work is to give a study on the morphological features of masks and respirators, which are widely accessible in Bulgarian shops and pharmacies, revealing their structure and differences between them. The results will be further used for the assessment of heat and mass transfer abilities of the masks/respirators, which are largely preconditioned by the masks' morphology. © 2022 IEEE.
ABSTRACT
Masks have been recommended as a protective tool for effectively combating the COVID-19 pandemic. In many countries, masks are required indoors, but the obligation temporarily and sporadically extends to all public places indoors and outdoors in some regions. Our study investigated the effect of wearing face masks in the classroom on the indoor environmental parameters and the human body experimentally. The study was performed at the Technical University of Sofia with 14 volunteers during regular lecture classes. Two stages were considered: with and without face masks. Measurement of the indoor environment parameters, oxygen (O-2) and carbon dioxide (CO2) concentration was continuously performed. Thermal image analysis was used to obtain the face thermograms of the participants. The results clearly showed the retention effect of the face masks on the exhaled air, leading to lower CO2 concentration in the classroom and higher O-2 concentration and humidity. It was also found that the continuous wear of a face mask for 40-45 min provoked an increment of the facial skin temperature under the mask to 37 degrees CC and even more. The rise of the temperature of the inner cantus of the eye showed that the face mask triggered the body's thermoregulation, causing thermophysiological reactions.
ABSTRACT
Wearing face masks in a pandemic is one way to limit the spread of viral particles. However, their use leads to a change in the dissipation of heat from the face to the environment. As a result, a microenvironment with increased air humidity, air temperature and carbon dioxide (CO2) concentration is formed under the mask. The aim of the paper is to present the design of a device for continuous measuring the temperature, humidity and concentration of CO2 in the microenvironment under protective face masks made of textiles. The requirements for the creation of such a device are complex: to fit well under the mask, not to impede the heat and mass transfer processes through the face mask, to support the sensors, to be reusable and to allow disinfection. The device will be used to determine the parameters of the microenvironment under protective masks of a different type. © 2021 IEEE.