As the government juggles vaccine distribution, virus management, and nationwide concern, the reopening of schools is a constant priority, as the C.D.C. has urged communities to return children to school but face hesitancy from parents and teachers alike. After months of online learning and a tentative modification into hybrid models, the effect of the pandemic on students has been widely observed in studies focusing on overall “learning gains” and levels of variability among classmates. Preventing further decline in the quality of education requires the reopening of schools and the subsequent return to an engaging and interactive environment– but that wholly depends on the ability of state governments and school administrators to comply with scientific recommendations and maximize safety within the classroom. 

After the application of a hybrid model, a typical classroom contains 20-30 students, all of whom are 6 feet apart and masked. These standard precautions provide an effective level of protection against the virus, yet the fact remains that 30 people, in close proximity, in a closed indoor area with low ventilation is simply a formula for disaster. A major cause of concern regarding the risk of contamination in schools is ventilation. With an airborne virus, the ability of indoor environments to circulate air is an influential factor in minimizing outbreaks and protecting students and staff. Through the mask, students’ breaths mix throughout the room, to the extent that about 3% of the air each person breathes has been exhaled by someone else. Presuming that there is an asymptomatic infected student in the room, as it is best to examine and therefore prevent all worst-case scenarios, this simple statistic confirms that the risk of contagion is high. Exposure, as said by environmental health expert Joseph G. Allen, is simply “a function of concentration and time”. Within a short time, perhaps the duration of a class period, the contaminants circulate around the room, which soon reaches its peak level of concentration. At this point, the damage has been done. Likely one or more students present will contract the virus. 

As a method of prevention, experts at the Healthy Buildings program recommend 4-6 air exchanges per hour in classrooms, most accessible through opening a window. The New York Times conducted a study and conferred with building system experts to determine the extent to which this open window will prevent contagion. The fresh air from external environments dilutes the contaminants and reduces their intensity, therefore limiting the rate of spread. As opening a window is dependent on weather conditions and placement of the classroom, experts also recommended another practical and inexpensive option: adding an air cleaner with a HEPA filter and a box fan blowing out. Both alternatives reduce exposure for students and lower levels of concentration– reducing the risk of an outbreak in schools and increasing the likelihood that schools will be able to stay open.