New antimicrobial technology for air filters can destroy bacteria, fungus, and viruses in seconds, including SARS-CoV-2, potentially preventing the spread of airborne diseases.

For the first time, researchers at the University of Birmingham have created novel antimicrobial technology for air filters that can destroy bacteria, fungus, and viruses such as SARS-CoV-2 in seconds, presenting a viable solution to limit the spread of airborne illnesses.

Scientists have published a study in the journal Scientific Reports today that shows how air filters with an antimicrobial coating, which are coated with a chemical biocide called chlorhexidine digluconate (CHDG), can be used in the lab, in industrial air condensers, and even on trains in the United Kingdom.

People in the lab added cells of SARS-CoV-2, which causes COVID-19, to both the treated and untreated filters. They measured them at different times over a period of more than an hour to see if the virus had spread to any of them. The findings revealed that, whereas a significant amount of virus persisted on the surface of the control filter for an hour, all SARS-CoV-2 cells were killed on the treated filter within 60 seconds of being exposed. Experiments with bacteria and fungi that typically cause illness in people, such as E. coli, S. aureus, and Candida albicans, yielded similar findings, demonstrating that the innovative technology is both very efficient anti-fungal and anti-bacterial air filter treatments.

Meanwhile, both the control and treatment filters were installed in train carriages’ heating, ventilation, and air conditioning systems to see how successful they are in a real-world environment. The filters were placed in matched pairs across carriages on the same train route for three months before being removed and shipped for investigation, with researchers counting bacteria colonies left on them. Even after three months on board the train, no bacteria remained on the treated filter, according to the trial.

Further studies revealed that the treated filters are long-lasting, with the ability to preserve their structure and filtration function over time.

“Most ventilation systems recycle air through the system, and the filters currently being used in these systems are not normally designed to prevent the spread of pathogens, only to block air particles,” says Dr. Felicity de Cogan. “This means filters can actually act as a potential reservoir for harmful pathogens. We are excited that we have been able to develop a filter treatment which can kill bacteria, fungi and viruses – including SARS-CoV-2 – in seconds. This addresses a global un-met need and could help clean the air in enclosed spaces, helping to prevent the spread of respiratory disease.”

While there have been other novel filters to ‘purify air,’ such as high-efficiency particulate air filters used in aerospace cabins, UV light, and silver nanoparticles added to filter mesh, according to Dr de Cogan, these have fallen short because they lack energy efficiency or speed in effectiveness, and are not suitable for the majority of existing heating, ventilation, and air conditioning systems, which would necessitate significant infrastructure upgrades to use them.

According to Dr. de Cogan, the technology they “have developed can be applied to existing filters and can be used in existing heating, ventilation and air conditioning systems with no need for the cost or hassle of any modifications. This level of compatibility with existing systems removes many of the barriers encountered when new technologies are brought onto the market.”

Source: 10.1038/s41598-022-06579-9

Image Credit: Getty

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