New technology could kill 99.9% of the deadly germs in the air

Air can be contaminated with dangerous germs known as airborne pathogens, such as bacteria and viruses like influenza (flu), common cold (rhinovirus), varicella zoster (chicken pox), mumps and measles.

Airborne diseases are very easily transmitted, and can result in respiratory illness that can be life threatening. It’s therefore no wonder that outbreaks of airborne infectious diseases are a major public health concern.

Now a new study suggests that non-thermal plasma – a cool gas made up of electrically charged particles, despite having no overall charge – could inactivate airborne viruses and provide sterile air. Although the technology has a long history and many applications (in medicine and food industry), this is a completely new use for it.

There are air disinfection methods currently available, but they have several limitations. Ultraviolet germicidal irradiation (UVGI), for example, is a disinfection method that uses ultraviolet light to kill or inactivate microorganisms by destroying their DNA so that they cannot reproduce inside the human body. However, over-exposure to UVGI has adverse health effect, leading to skin erythema (superficial reddening of the skin) and a painful eye condition known as photokeratitis.

Air filtration is a good method to clean the air, removing particles and stops outside pathogens from penetrating into buildings such as healthcare facilities. However, some airborne pathogens are too small to be removed and can pass through air filters.

Non-thermal plasma can inactivate 99.9% of airborne viruses through releasing energetic, charged fragments of air molecules that can destroy viruses in less than a second. The non-thermal plasma can also kill bacteria through destruction of their cell wall.

The plasma was produced in a non-thermal plasma reactor. When pathogens in the air pass through it, they atoms called radicals (such as ozone). These alter the lipids, proteins and nucleic acids of the microorganisms they encounter – killing the pathogens or rendering them harmless. The device also works by filtering pathogens from the air stream.

Combining filtration and inactivation of airborne pathogens will provide a more efficient way of providing sterile air than current devices.

While the device is effective, is it safe? We know that ozone is linked to respiratory conditions. But the researchers say that ozone exposure from the device is within regulation standards.

So, it looks like non-thermal plasma reactors have the potential to replace the traditional face mask and provide sterile air – especially in crowded areas such as on public transport, and in schools and hospitals.

Given how difficult it is to prevent the transmission of airborne disease, this is great news.