Cold plasma furnaces reduce 99% of airborne viruses

Cold plasma reactors can oxidize viruses, causing them to lose their ability to invade human cells and cause infectious disease.

At the University of Michigan, Herek Clack, associate professor of Civil and Environmental Engineering at the University of Michigan and colleagues developed a cold plasma reactor that makes airborne pathogens unable to infect thread objects, including children. people. Plasma oxidizes the virus, neutralizing their cell entry mechanism.

Filters have long been used to remove fine particles, including viruses and bacteria from the air we breathe. This is a key component in the ventilation system in buildings and airplanes. However, many viruses smaller than the smallest particles are usually trapped by filters. One measure to reduce the spread of pathogens in the air is the cold plasma reactor.Plasma is the fourth state of matter, a gas composed of ions and electrons instead of neutral nuclei and atoms. A cold state means that the plasma does not form at high temperatures.

The researchers tested the prototype of a cold plasma furnace on a pig farm in Michigan to prevent the virus from causing blue-ear disease.(Photo: Robert Coelius).

After testing in laboratories and livestock farms, the team found that the reactor helped reduce more than 99% of the infectious disease virus in a gas mass. They are developing technology for use in agriculture and say the product is also useful in places where many people concentrate in enclosed spaces, including commercial airplanes.

Scientists don't know what makes some viruses and bacteria stay longer in the air, like tuberculosis and measles. A recent study showed that influenza viruses can spread in the air for more than an hour. Closed or crowded spaces reduce the level of virus attenuation, which increases the risk of infection when exposed.

There are several theories about the mechanism of killing bacteria of cold plasma, but viruses in the air are different from bacteria and cannot be killed in the same way. The researchers' understanding of cold plasma sterilization is based largely on the process of sterilizing contaminated surfaces by spraying plasma for many minutes, much longer than the exposure time of less than a second in the study. by Clack et al.

In the team's experiments, plasma reduced only more than 99% of the virus in the air but did not change the viral DNA. This means that the plasma cannot destroy the virus but only changes its ability to infect. Clack and his colleagues are exploring the mechanism of this process to regulate the reactor.

They are also considering how to use cold plasma reactors on board. Long-haul flights can take infected passengers around the world. There are many factors that determine the transmission of a virus in an aircraft's cabin, including in-flight maneuver. Airflow patterns in the cabin also play an important role in determining how far the virus from an infected person spreads. Researchers need to better understand these fluctuating factors before the aircraft manufacturer and airline can use the cold plasma reactor to prevent infectious disease from spreading.