President Donald Trump has proposed scientists look into injecting disinfectant as means of killing the novel coronavirus, an idea that was quickly shot down by experts.
The suggestion made at a White House briefing on Thursday is the latest of several scientifically dubious or unproven methods raised by the US president to counter the virus, which has claimed nearly 50,000 lives so far in the United States.
It came after a Homeland Security official reported the findings of US government study on the effects on the virus from disinfectants and from higher heat and humidity.
Department undersecretary Bill Bryan said research had shown bleach could kill the virus in saliva or respiratory fluids in five minutes and isopropyl alcohol could kill it even more quickly.
Mr Trump picked up on the idea when he took the podium.
“The disinfectant knocks it out in a minute. One minute,” he said. “Is there a way we can do something like that by injection inside?” He said it would be “almost a cleaning. It gets in the lungs and does a tremendous number on the lungs.”
However, bleach is a toxic chemical, and inhaling it could damage the lungs.
“Inhaling chlorine bleach would be absolutely the worst thing for the lungs,” said John Balmes, a pulmonoligist at Zuckerberg San Francisco General Hospital, and a professor of medicine at the University of California San Francisco.
“The airway and lungs are not made to be exposed to even an aerosol of disinfectant,” Dr Balmes told Bloomberg news agency.
“Not even a low dilution of bleach or isopropyl alcohol is safe,” he said. “It’s a totally ridiculous concept.”
Mr Trump also proposed exposing the body to light after Mr Bryan said the study had found that the coronavirus survived for a shorter time on door handles and other nonporous surfaces when it was exposed to sunlight, higher temperatures and humidity.
“Suppose we hit the body with a tremendous ultraviolet or just very powerful light,” the president said. “I think that hasn’t been checked but you’re going to test it.”
Researchers could also bring “the light inside the body”, Mt Trump said, “either through the skin or in some other way.”
The World Health Organisation has warned against using UV lamps to sterilise any part of the body, saying it can cause skin irritation.
However, the study appeared to bear out Mr Trump's suggestion in February that the exposed virus might be affected by warmer spring temperatures.
“The virus is dying at a much more rapid pace” from exposure to humidity or heat, Mr Bryan told the briefing.
The new research offered practical tips for many Americans, including “increasing the temperature and humidity for potentially contaminated indoor spaces” in order to kill the virus on surfaces, he said.
At a temperature of 21-24°C and 80 per cent humidity in the summer sun, for example, the research showed the virus would last just two minutes on a porous surface, Mr Bryan said. Dry environments may require “extra care”.
More than 870,000 people in the U.S. have been confirmed infected with the virus and more than 49,000 have died. About 20,000 new cases were added on Thursday.
As some US states begin planning to roll back social-distancing restrictions, an important question has become whether summer heat might impact the virus – and whether the autumn might bring a new outbreak, as some experts inside and outside the government have suggested.
Weather and UV rays are often an important factor in the transmission of infectious diseases. Transmission of the flu, for example, is often correlated with cold temperatures and dry air. One study found that in northern Europe, low temperature and low UV indexes coincided with peaks of the flu virus in the period between 2010 and 2018.
“We know that respiratory viruses are quite seasonal. Coronaviruses are also respiratory viruses, and we had hope and anticipation it would be, too,” said William Schaffner, an infectious disease professor at Vanderbilt University in Nashville, Tennessee. But, he said, not all coronaviruses show strong seasonal variation, and it is not clear that this one will.
Scientists continue to research the new coronavirus, and the pathogen has circulated in parts of the world with high, humid temperatures. Singapore is experiencing a surge of cases despite hot, humid weather. And in the developed world, many people spend much of their time indoors in controlled, cooler, drier environments without direct sunlight.
Anthony Fauci, the National Institutes of Health scientist on the White House task force, said in an April 9 television interview that, “one should not assume that we are going to be rescued by a change in the weather. You must assume that the virus will continue to do its thing.”