And no mask works if the wearer doesn’t cover their mouth and nose at all times. Well-fitted masks with multiple layers are best. Loosely folded face masks and bandana-style coverings don’t capture the smallest droplets. However, not all masks are equally effective. Not only do masks minimize the number of droplets that escape, they slow down the droplets that aren’t stopped and reduce the distance they can travel – all of which are crucial in close quarters. The best way to prevent the spread of COVID-19 on school buses is to ensure that everyone wears masks, which are safe for children 2 and up to use. To be sure, some could prove impractical due to the nature of children and the budget realities in school districts everywhere. These eight recommendations are best practices for families and school leaders to take into consideration. The Centers for Disease Control and Prevention recently updated its school bus guidance, and several educational transportation trade groups have produced a task force report with detailed guidance of their own. But some school districts have welcomed students back into classrooms. The number of children regularly boarding school buses has plummeted from around 25 million before the pandemic due to the large number of students who are doing remote learning either full-time or several days a week. Open windows bring in fresh air and dilute the overall concentration, greatly reducing the risk of an outbreak. However, smaller droplets can remain suspended for hours and carry the coronavirus throughout the bus.Īir currents generated by heating, ventilation and air-conditioning – often referred to as HVAC systems – are capable of spreading these droplets, which scientists call “ aerosols,” from an infected person to other passengers. Large droplets – to be exact, those greater than 50 microns across, about as wide as a human hair – tend to fall within a couple of feet and deposit in the confines of the seat. But it is now established, based on an analysis from recent outbreaks, that the virus is predominantly spreading from one person to another through airborne droplets.ĭroplets of various size are expelled when you cough, sneeze, sing or even just speak. It’s not yet clear what the minimum dose of the coronavirus is to become infected. Credit: Zhihang Zhang, Jesse Capecelatro, Kevin Maki, Jim Smith and Jason Bundoff. Numerical model showing the flow of air and concentration of aerosols inside a campus bus.
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