Microwave Radiation as a Method for Killing Covid and Other Viruses?

 You can find the article here, and you can find more from the Air Force Research Lab here. 

Introduction

During the Sars-Cov-E-2 pandemic (COVID-19), numerous methods were attempted to reduce viral transmission, including temperature variation in both hot and cold weather (Who), alcohol (BBC),  and bleach (Who). Despite many of these ideas, which were the result of misunderstood science, falling short of decreasing viral transmission and destroying the virus, several methods which showed previous interesting results were brought back into the limelight to be reanalyzed. Of these, the use of non-thermal microwave radiation to kill COVID-19 was explored, despite previous results indicating microwave radiation performing poorly against viral infection (Epstein and Cook 1951). In recent years, evidence has shown that non-thermal radiation inactivation may host a proposed mechanism involving the electromagnetic coupling of microwave radiation to mechanical dipole resonances, meaning microwaves can cause mechanical stress if at the right frequency (Lui et al 2009). This effect, known as the structure-resonant energy transfer (SRET), has been seen in previous explorations which have covered SRET and thermal effects on pathogen inactivation (Xiao et al. 2022).  Researchers hypothesized that high-powered microwaves may cause more mechanical damage to viruses, but studies indicated that inactivation of viruses from microwaves was less than 75% (Cantu et al. 2023). In this study, four frequencies of microwave which were noted as being “of interest” for inactivation of Bovine Coronavirus (BCoV) were explored for BCoV in aerosols. Previous studies by this group (Hoff et al. 2023) showed roughly 74% inactivation of BCoV in aerosol when exposed to 5.6 GHz. In order to obtain a more comprehensive evaluation of microwave-virus interactions, this study hypothesized that exposing aerosolized BCoV to a lower frequency of microwave, namely 4.0 GHz would result in weaker inactivation compared to 5.6 GHz. 

Methods

Cohick et al. used a custom built experimental apparatus which allowed them to pump aerosolized BCoV down a tube which had consistent radiation. This set-up included aerosol being generated using a nebulizer. Once generated, the aerosol would flow down a polycarbonate flow tube into a biosampler.

Figure 1) Custom apparatus used to explore radiation effects on aerosolized viruses, including the collision nebulizer (left) and the biosampler (right) and the radiation input (center). 

Findings

 46 experiments were carried out (20 with RF exposure and 26 control/no-RF exposure).  Each experiment took 15 minutes to complete. After the virus was aerosolized and irradiated, virus survival rates were analyzed using a TCID50 assay, which is a method of determining the infectious virus titer by calculating the dilution required to produce a known cellular effect, such as cell death. Their results indicated there was no statistically significant reduction in BCoV survival rate while under 4.0 GHz radiation in comparison to BCoV under no radiation. There was also no statistically significant increase in the standard deviation when comparing the results under RF exposure and control. 

Figure 2) BCoV survival rate for irradiated samples and control samples. Median and interquartile ranges are depicted, alongside raw data.

Conclusion

Given previous results showing that BCoV had a strong reduction in survivability under higher frequencies but a lessening reduction in survivability under smaller frequencies (Cantu et al. 2023) this result is consistent.  Furthermore, this trend is noted as aligning with observations in other SRET work involving the neutralization of viruses. Cohick et al. plan to continue experiments on aerosolized BCoV under high frequencies and exposures of BCoV virus to shorter RF pulse lengths. They hope to create a more comprehensive understanding of how frequency-based radiation may affect the survivability of COVID-19.

Citations

Cohick, Z. W., Hoff, B. W., Revelli, D., Cox, J., Irshad, H., Snider, A., Arndt, A., Enderich, D. A., McCohaha, J. W., Schrock, J. A., Ibey, B. L., Thomas, R. J., Luginsland, J. W., Roach, W. P., & Shiffler, D. A. (2026). Evaluation of 4.0 ghz RF exposure effects on bioaerosols containing bovine coronavirus. Bioelectromagnetics, 47(1). https://doi.org/10.1002/bem.70040 

BBC. (2020, March 5). Coronavirus: Don’t use vodka to Sanitise Hands. BBC News. https://www.bbc.com/news/business-51763775 

WHO. (2022, January 19). Covid-19 mythbusters. World Health Organization. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/myth-busters 

Epstein, M. A., and H. F. Cook. 1951. “The Effects of Microwaves on the Rous No. 1 Fowl Sarcoma Virus.” British Journal of Cancer 5, no. 2: 244–251. https://doi.org/10.1038/bjc.1951.25.

Liu, F., B. Rittmann, S. Kuthari, and W. Zhang. 2023. “Viral Inactivation Using Microwave‐Enhanced Membrane Filtration.” Journal of Hazardous Materials 458: 131966. https://doi.org/10.1016/j. jhazmat.2023.131966.

Xiao, Y., L. Zhao, and R. Peng. 2022. “Effects of Electromagnetic Waves on Pathogenic Viruses and Relevant Mechanisms: A Review.” Virology Journal 19, no. 1: 161, 2022/10/12. https://doi.org/10.1186/s12985-022-01889-w. 

Cantu, J. C., J. W. Butterworth, K. S. Mylacraine, et al. 2023. “Evaluation of Inactivation of Bovine Coronavirus by Low‐Level Radiofrequency Irradiation.” Scientific Reports 13, no. 1: 9800. https://doi.org/10.1038/s41598-023-36887-7.

Hoff, B. W., Z. W. Cohick, B. S. Tilley, et al. 2023. “Observed Reductions in the Infectivity of Bioaerosols Containing Bovine Coronavirus Under Repetitively Pulsed RF Exposure.” IEEE Transactions on Biomedical Engineering 70, no. 2: 640–649. https://doi.org/10.1109/TBME.2022. 3199333.