The research focuses on the synergistic effects of ultraviolet (UVA and UVC) irradiation and hydrogen peroxide (H₂O₂) in neutralizing aerosolized viruses, with an emphasis on creating conditions closely mimicking typical indoor air environments, in a controlled 19 m³ atmospheric chamber.
The experimental setup employed an aerosol generator that operated based on the saturator/condenser mechanisms. Through this system, the original size of the particle (120 nm) increased to 550 nm, forming a complex structure consisting of the virus (bacteriophage T4) and mucin solution enveloping it.
Key findings demonstrate the potent, dose-dependent virus inactivation capabilities of UVC irradiation, achieving 90%, 99.8%, 99.9% virus DNA destruction at UVC dosages of 7, 8.93, and 17.83 mJ.cm^-2, respectively, of the initial viral load.
The study further explores UVA irradiation's contributory role in decreasing virus viability, particularly at higher doses, underlining its potential as an auxiliary disinfection method. Our results showed that UVA, at a dose of 135.5 J.cm^-2, resulted in an 80% viral load decreasing for the T4 bacteriophage.
Additionally, the effectiveness of H₂O₂, both in the absence and presence of UV light, reveals its potent antiviral properties, significantly enhancing viral DNA destruction. The present study reveals that even low concentrations of hydrogen peroxide (<1 ppm) can significantly destruct airborne viruses, with effectiveness increasing as the concentration rises. For example, at just 32 ppb, we observed a 78% of DNA molecules were destructed compare to initial condition. Our results demonstrated that for the UVA with the doses of 135.5 J.cm^-2and UVC with the doses of 6.7 mJ.cm^-2, over 99.999 of the initial loaded virus DNA was destructed, Fig. 1.
The integration of UVA or UVC irradiation with H₂O₂ in the gas phase represents a promising air disinfection technology, with significant implications for public health and indoor air quality management.

Figure 1. The effect of H<sub>2</sub>O<sub>2</sub> on the detected DNA of T4 for different UV light sources.

Figure 1. The effect of H₂O₂ on the detected DNA of T4 for different UV light sources.

Ali Mohamadi Nasrabadi

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