Quartz – The reason is rooted in science history: “Covid, it’s now an established fact, is airborne. Like other infectious diseases such as measles, chickenpox, or tuberculosis, it spreads through aerosols that can stay in the air for long periods of time, and travel long distances. The airborne quality of the virus is recognized by public health authorities including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC). Yet when the virus emerged, and for some time afterward, public health authorities thought instead that the virus might spread through large droplets, which unlike aerosols can only travel about two meters, and can fall on nearby surfaces, which in turn become potential vehicles of transmission. This was the theory that had everyone wiping down their groceries and wondering whether to disinfect their mail in early 2020. Though aerosols and droplets may sound similar, their public health implications are very different. The assumption that covid was spread by droplets informed public health advice such as stressing the importance of social distancing, wearing any kind of mask including cloth ones, and disinfecting surfaces—as opposed to focusing on high-quality masks that can stop aerosol transmission (such as N95s) and ventilation. But evidence that covid was airborne was abundant early on—what was lacking was the will to accept it. The WHO labeled the theory of airborne transmission as misinformation, and worked to dispel it, sharing on its social media channels: “#FACT: #COVID19 is NOT airborne.” Yet as early as April 2020, a team of scientists presented evidence of aerosol transmission of covid to the WHO, gathered by studying the transmission dynamics of some superspreader events. “I said well, we will explain it to them, and then we’ll have a reasonable debate as scientists,” said Jose Jimenez, a professor of chemistry at the University of Colorado, Boulder, who was on the team led by renowned atmospheric physicist Lidia Morawska. But the WHO team, he said, was closed to the idea, and one of them was even rude and yelled at Morawska. It took almost two more years for the WHO to acknowledge she was right all along…”