School detections account for the fastest growing positivity rates as we close 2020. The dynamics of transmission via aerosols in the classroom change completely depending on whether the infected person – or patient zero – is a student or a teacher.
Teachers talk far more than students and raise their voices to be heard, which multiplies the expulsion of potentially contagious particles. In comparison, an infected student will only speak occasionally. According to the Spanish National Research Council (CSIC) guidelines, the Spanish government has already recommended that classrooms be well ventilated.
the riskiest scenario is a classroom with no ventilation and the teacher – patient 0 – as the infected person.
If two hours are spent in the classroom with an infected teacher, without taking any measures to counter the number of aerosols, there is the risk that up to 12 students could become infected.
If everyone is wearing a face mask, the number that could become infected drops to five. In real outbreaks, it has been noted that any of the students could become infected irrespective of their proximity to the teacher as the aerosols are distributed randomly around the unventilated room.
If the room is ventilated during the lesson, either with fresh air or mechanically, and the class is stopped after an hour in order to completely refresh the air, the risk drops dramatically.
For several months, schools have been searching for ways to get students safely back to classrooms and campuses. It’s been the focus of administrators, parents, teachers, scientists, municipalities, and others.
Closures and other limited access measures have burdened parents, social support systems, local governments, and of course, students themselves. While some schools have been able to reopen, many more have failed. Some schools have already invested heavily in disinfection and safety solutions – and yet still have fallen short of getting back to normal