200 Scientists Say WHO Ignores the Risk That Coronavirus ‘Aerosols’ Float in the Air

“Six months into a pandemic that has killed over half a million people, more than 200 scientists from around the world are challenging the official view of how the coronavirus spreads,” reports the Los Angeles Times: The World Health Organization and the U.S. Centers for Disease Control and Prevention maintain that you have to worry about only two types of transmission: inhaling respiratory droplets from an infected person in your immediate vicinity or — less common — touching a contaminated surface and then your eyes, nose or mouth. But other experts contend that the guidance ignores growing evidence that a third pathway also plays a significant role in contagion. They say multiple studies demonstrate that particles known as aerosols — microscopic versions of standard respiratory droplets — can hang in the air for long periods and float dozens of feet, making poorly ventilated rooms, buses and other confined spaces dangerous, even when people stay six feet from one another. “We are 100% sure about this,” said Lidia Morawska, a professor of atmospheric sciences and environmental engineering at Queensland University of Technology in Brisbane, Australia. She makes the case in an open letter to the WHO accusing the United Nations agency of failing to issue appropriate warnings about the risk. A total of 239 researchers from 32 countries signed the letter, which is set to be published next week in a scientific journal. In interviews, experts said that aerosol transmission appears to be the only way to explain several “super-spreading” events, including the infection of diners at a restaurant in China who sat at separate tables and of choir members in Washington state who took precautions during a rehearsal… The proponents of aerosol transmission said masks worn correctly would help prevent the escape of exhaled aerosols as well as inhalation of the microscopic particles. But they said the spread could also be reduced by improving ventilation and zapping indoor air with ultraviolet light in ceiling units. The Times also got a response from Dr. Benedetta Allegranzi, a top WHO expert on infection prevention and control, who argued the group only presented theories based on experiments rather than actual evidence from the field. Allegranzi also added that in weekly teleconferences, a large majority of a group of more than 30 international experts advising the WHO had “not judged the existing evidence sufficiently convincing to consider airborne transmission as having an important role in COVID-19 spread.”