Following the COVID-19 outbreak, Columbia University in the United States and Kobe University in Japan both announced studies that demonstrated that distant UVC light with a wavelength of 222nm inactivates the coronavirus and is safe for skin.
Recently, Columbia University published the latest research results, proving that far UVC light can kill seasonal coronavirus spread by air droplets, the inactivation rate of 99.9%. Using remote UVC light to continuously sterilize human indoor environments within regulatory limits could significantly reduce airborne viruses, the researchers said.
The team has previously shown that remote UVC light can safely kill airborne influenza viruses, and this time they are extending the scope of their study to novel coronavirus, a type similar in structure to the novel Coronavirus.
During the study, the researchers used a sprayer to atomize two common coronaviruses, and the aerosol containing the coronavirus then flowed in front of the remote UVC lamp. After being irradiated, the researchers then tested how many viruses survived.
On the basis of this study, the researchers estimated that within the limits of existing regulations, the inactivation rate of airborne virus by irradiation with remote UVC light for 8 minutes was 90%. The inactivation rate was 95% after irradiation for 11 minutes. The inactivation rate was 99% after irradiation for 16 minutes. The inactivation rate was 99.9% after 25 minutes of irradiation.
Meanwhile, the effects of novel Coronavirus with remote UVC light were tested. Preliminary data showed that far UVC was equally effective in killing novel Coronavirus. According to the lead researcher, the novel Coronavirus could not be truly distinguished by far UVC light, so the team expects it to be able to kill the virus in the same way.
By showing that far UVC light wavelength of 222 nm to kill the effect of airborne viruses, the researchers think the disinfection system based on far UVC light can in medical institutions, buses, planes, trains, railway stations, schools, hotels, offices, movie theaters, the gym some indoor public places such as the safe use, reduce the coronavirus and human-to-human transmission of influenza virus types and other risks.
The study has now been published in the journal Scientific Reports.
According to LEDinside, there has been a lot of controversy in the first half of this year about the efficacy and safety of 22-nm UVC light, and research teams have continued to conduct research. Among them, the industry still expects more in-depth studies to prove the preliminary results in terms of the security of 222nm UVC.