In a reference study, researchers found that UV light emitting diodes (LEDs) can quickly and effectively destroy human coronavirus. If they are effective against SARS-CoV-2, this technology could be a cheap way to disinfect surfaces, ventilation systems and water systems.
It is well known that SARS-CoV-2, which is the virus that causes COVID-19, can spread through respiratory droplets and surfaces contaminated with nasal, oral and ocular secretions.
According to a review article in the journal Environmental research, SARS-CoV-2 has been present in air samples from areas such as hospital rooms and elevators. It was also measurable in poorly ventilated or crowded spaces.
SARS-CoV-2 was also viable for several days on common surfaces such as stainless steel and plastic.
Due to the urgent need to find effective methods of disinfection for SARS-CoV-2, researchers at Tel Aviv University in Israel – in collaboration with the University of Haifa, Oranim Academic College and Chaim Sheba Medical Center in Tel HaShomer – have begun to investigate whether or not irradiation using the UV LED would inactivate human coronaviruses.
They recently published their results in Journal of Photochemistry and Photobiology B: Biology.
Using human coronavirus OC43 (HCoV-OC43) as a replacement for SARS-CoV-2, the research team tested various UV LED bulbs that emit variable wavelengths – measured in nanometers (nm) – to see which would inactivate HCoV-OC43 virus is effective.
After exposing the viral suspensions placed in dark tubes to UV LED light, the team found that the 285 nm wavelengths were extremely effective at inactivating the virus and almost as effective as the 265 nm wavelengths, inactivating 99.9% of coronavirus in less than 30 seconds.
Moreover, other viruses have shown similar sensitivity to these wavelengths, indicating that this technology could be useful against many types of human coronavirus, including SARS-CoV-2.
Researchers say these findings are significant because not only does 285 nm UV LED light disinfect coronaviruses, but it is also less expensive and easier to access than the 265 nm variety.
“I found it quite easy to kill the coronavirus using radiant LED bulbs [UV] Easy. ”
– Prof. Hadas Mamane
Because the researchers used HCoV-OC43 instead of SARS-CoV-2, they say their future work will aim to confirm these results by testing the impact of LEDs and their combinations on the virus that causes COVID-19.
According to the study’s co-author, Dr. Yoram Gerchman Medical news today, “SARS-CoV-2 requires a biosafety laboratory 3 (BSL3) to spread (though not for analysis) because the disease it causes is much more severe.”
“The [HCoV-OC43 virus] it only needs a level of biological safety 2 [laboratory]. At that time, BSL3 [laboratory] into the [the] The virology center of Sheba Hospital was under renovation and I didn’t want to be late. “
Dr. Gerchman explains that it is common to use bacteriophages, which are viruses that infect bacteria, but not humans, as surrogates, because researchers can work with them in a tier 1 safety laboratory.
In addition, the surrogate virus team used in the study belongs to the same genus betacoronavirus as SARS-CoV-2 and closely resembles its size and structure.
Despite the success of UV LED irradiation on human coronaviruses, the Tel Aviv University press release warns that this technology is dangerous and does not recommend it for residential use. The authors say that it is necessary to design a system that uses UV LEDs.
The COVID-19 pandemic has increased the use of disinfectants in both public and household settings.
Recent research in the journal Environmental science and technology letters found an increase in the number of quaternary ammonium compounds (QAC) in house dust collected from homes after the pandemic began. QACs are chemicals in cleaning and disinfection products that cause reproductive and respiratory damage.
In addition, the use of large amounts of disinfectants can harm wildlife and the urban environment, according to a journal review. Environmental research.
Due to the dangers of chemical methods, professionally designed UV LED disinfection systems can be a safer solution – one that can disinfect surfaces, air and water.
According to Prof. Mamane, the researchers “killed the viruses using cheaper and more easily available LED bulbs, which consume less energy and do not contain mercury like ordinary light bulbs.”
“Our research has commercial and societal implications, given the ability to use such LED bulbs in all areas of our lives, safely and quickly.”
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