Sunlight, heat, and humidity weakens coronavirus, says US official
On Thursday, a US official said the deadly coronavirus weakens when exposed to sunlight, heat, and humidity, making way for hopes that the pandemic might come to an end in summer months. William Bryan, acting head of the US Department of Homeland Security's Science and Technology Directorate, said at a White House briefing that the virus best survives indoors and in a dry environment.
Bryan based his statements on a research conducted by the US Army's high biosecurity laboratory at Fort Detrick. The research hasn't been peer-reviewed yet. The half-life of coronavirus, which is the time taken for a virus to reduce its strength to half, was studied for this. The US official explained coronavirus' half-life was reduced from 18 hours to one hour indoors when the humidity increases from 20 to 80%.
On non-porous surfaces like stainless steel/door handles, the half-life dropped from 18 hours to six hours, when the humidity was increased. When sunlight was added, the half-life came down from six hours to just two minutes. In a dark room, the virus maintained half of its strength for an hour. In the presence of sunlight, it lost its strength in 90 seconds.
"Within the conditions, we have tested to date, the virus in droplets of saliva survives best in indoors and dry conditions. ... The virus dies quickest in the presence of direct sunlight," he summarized.
While his statements provide a ray of hope, there are some questions that remain unanswered. The foremost being — if the virus is less lethal in warmer temperatures, why has the death toll risen in countries like Singapore? Bryan, on his part, also cautioned by saying "it would be irresponsible for us to say summer will kill the virus".
Naturally, Bryan's words made United States President Donald Trump happy as he reminded of the criticism he faced earlier for saying summer months will bring good news. "I just threw it out as a suggestion, but it seems like that's the case because when it's on a surface, that would last for a long time. It dies very quickly with the sun," Trump said.
According to Bryan, researchers have also concluded that isopropyl alcohol was a more effective disinfectant than bleach. Subsequently, Trump said researchers should use these findings on coronavirus patients by "inserting light or injecting disinfectant". "Is there a way we can do something like that by injection, inside, or almost a cleaning? It would be interesting to check that," the President of the US said.
Trump's handling of the virus has regularly been criticized as the death toll in the country reached 50,243 and infections rose to 886,709. Globally, the COVID-19 disease has killed 191,055 with the number of infections standing at 2,725,391.