TESTING
How Coronavirus Advanced Filtration Efficiency AND THE INDUSTRY By Nikki Sasher
P
eople spend 90% of their time in indoor environments, making air quality one of the most profound health implications for the world’s population. Addressing this global public health concern requires a clear understanding of the transmission processes of infections by developing and implementing targeted infection prevention and control measures. Worldwide outbreaks of severe acute respiratory syndrome (SARS) and other viral agents have caused a substantial health impact on the population and have increased public concerns about the spread of viral disease. The global pandemic caused by the novel coronavirus SARS-CoV-2, which caused the disease known as COVID-19, has changed the world in ways no one could have imagined. There is much more to learn about this ever-changing global threat. However, some aspects of the virus are known, such as its main route of transmission being that of an airborne nature. Therefore, there is a strong effort to mitigate risk to
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the general population through the use of engineering controls such as improved air filtration.
A Word on Particles As it relates to human health, particles with a diameter of 10 microns or less (≤ PM10) can penetrate and lodge inside the lungs. Particles with a diameter of 2.5 microns or less (PM2.5) can penetrate deeply into the lungs, particles less than 0.5 microns in size can pass through the blood/gas barrier and enter the bloodstream, and chronic exposure to particles contributes to the risk of developing cardiovascular and respiratory diseases, as well as lung cancer. Particles can be viable or non-viable in nature. Viable particles contain one or more living organisms such as bacteria or fungi, and their size generally ranges from 0.2-30 microns. Viable particles can survive and replicate independently. Nonviable particles include particles that commonly consist of a complex mixture of solid and liquid particles of organic and inorganic substances suspended in air.
Viruses are in a different classification, in that they are parasitic, not free-living or able to transport themselves, and require a transport particle followed by a host to survive and replicate. Non-viable particles are the main source of movement for all other particles and are commonly referred to as transport particles.
Background on Viral Testing at AAF Clean AIR Center In 2015, the University of Minnesota developed a test to evaluate filter performance using a 50-nanometer swine virus, an adaptation of the ASHRAE 52.2 (2012) method, and molecular virology to quantify the percent reduction of virus with mechanical capture based on transport particles entrapped within filter media. The goal of this study was to develop a standardized method to evaluate filter performance against a virus of interest in the swine industry and ultimately provide producers with a procedure to evaluate filter efficiency. In 2018, before the coronavirus pandemic, AAF Flanders worked with the
