US study: open windows in the classroom kill 70 percent of the virus

2020-10-21T07:22:15.027Z

Windows open to disperse up to 70% of virus particles and protective screens in front of the desks to slow their spread: so physicists have calculated how to reduce the circulation of the new coronavirus at school, within the classrooms. The research, published in the journal Physics of Fluids, is due to physicists from the American University of New Mexico. The study of the transport of aerosols and droplets of saliva within closed environments can help establish effective measures to counter the spread of the Sars-CoV-2 virus. One of the most important environments for gaining a quick understanding of the spread of virus particles, the authors note, is the classroom. Researchers used a fluid particle dynamics model to explore aerosol transport within an air-conditioned classroom. It emerged that the distribution of the aerosol inside the room is not uniform, due to the air conditioning and the position of the source and that, said one of the authors, Khaled Talaat, "the particles can be transmitted from one student at the desks or clothes of other students, even if kept separated by a distance of 2.4 meters ". According to Talaat, "the position of the student in the classroom affects the likelihood of transmitting particles to others and receiving them". However, it was found that "almost 70% of the particles leave the system when the windows are open". In addition, the expert added, the research shows that "air conditioning removes up to 50% of the particles released during exhalation and conversation, but the rest settles on the surfaces inside the room and can re-enter. air". As a result, research also highlights the importance of using effective filtration and sterilization systems in air conditioners. The study also shows that even the protective screens placed in front of the benches significantly reduce the transmission of particles from one student to another, because explained Talaat "they influence the circulation of the air flow near the source, making the trajectories of particles change. ".