By Herek Clack
It’s the enduring media image of infectious disease outbreaks, including the current coronavirus outbreak from Wuhan, China: people in public spaces with faces half-hidden by surgical masks.
Filters have long been used to remove particles, including viruses and bacteria, from the air we breathe. Particle filters are key components of building and aircraft ventilation systems. Unfortunately, viruses are much smaller than the smallest particles those filters typically capture reliably.
One possibility for curbing the spread of airborne pathogens is a nonthermal plasma reactor. Plasma is the fourth state of matter, a gas composed of electrically charged ions and electrons rather than neutral atoms and molecules. Nonthermal means the plasma isn’t formed at high temperatures. At the University of Michigan, my colleagues and I developed a nonthermal plasma reactor that leaves airborne pathogens unable to infect host organisms, including people. The plasma oxidizes the viruses, which disables their mechanism for entering cells.
After testing in the lab and at livestock facilities, we’ve shown that the reactor reduces the numbers of infectious viruses in an air stream by more than 99%. We’re developing the technology for use in animal agriculture, but it might also be useful where people are concentrated in enclosed spaces, including commercial aircraft.