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Yesterday the White House published a blog post titled "Let's Clear the Air on COVID," describing the virus as primarily transmitted through aerosols—small, tiny airborne particles. Though some experts around the world have been arguing that point for years, and subsequently advocating for respirator use and enhanced ventilation systems, this is the first time the White House has formally acknowledged that aerosol transmission has been the primary driver of the COVID-19 pandemic. In doing so, it has turned away from the language used by the Centers for Disease Control and Prevention (CDC). (Soucheray, 3/24)

For Catherine Noakes, a scientist who studies how pathogens move in the built environment, the first few months of the coronavirus pandemic were punctuated with a foreboding sense of frustration. That frustration was rooted in the readily accepted assumption that COVID-19 was not spreading through the air via microscopic particles called aerosols, but predominantly through larger respiratory droplets expelled among people in close proximity and falling quickly on nearby surfaces. (Grover, 3/11)

A research team at the University of Oregon says ventilation, filtration, and humidity levels of an indoor room can reduce how easily a virus spreads. Additionally, they found there was not much difference in the number of virus particles projected through the air between people standing 4 feet (ft) or 11 ft away. The team believes their findings can assist building operators in creating an indoor environment that helps improve the health and safety of those inside. (Pelc, 3/2)

There is ample evidence that SARS-CoV-2 can become airborne1 and that ventilation reduces the risk of transmission,2 but the difficulty is what to do about it. For all the sensitivity of the human senses, our eyes and ears cannot tell us whether the air in a room is full of aerosols harbouring SARS-CoV-2. But what if we could measure the freshness of that air and, therefore, get a rough idea of how safe we’d be in a particular indoor space—or at least how well ventilated it is? Carbon dioxide (CO2) monitors, which measure concentrations of the gas in parts per million (ppm), have emerged as one way to do that. (Baraniuk, 3/23)

The Centers for Disease Control and Prevention on Thursday updated its guidance so that people visiting health care facilities are allowed to wear highly protective masks such as N95s. The change comes after a POLITICO report last week found that hospitals around the country routinely ask patients and visitors to wear a surgical mask instead of their own N95. (Levy, 3/24)

As COVID-19 cases were reported to be on the rise in nine states, the director of the Centers for Disease Control and Prevention emphasized Thursday in a visit to Princeton University that the pandemic is not yet over. “We’re not at a steady state of disease that I can be happy with,” Rochelle Walensky said. “We still have 900 deaths a day in this country. I still think we have a lot of work to do to make sure that we’re in a place that is safe for this country and for the American people.” (Laughlin, 3/24)