CLEVELAND, Ohio – From the morning bus ride to recess. From the classroom to the cafeteria. As students go about their school day in the age of COVID-19, the threat of contracting the deadly virus ebbs and flows, based on the availability of masks, fresh air and space between one another.

Given the reality that children below the age of 12 are still ineligible for vaccination, and that many schools are not requiring masks, what we know today about the virus could induce panic in any parent sending their child back to the classroom. We know that the predominant Delta variant is roughly twice as infectious as the original. And public health authorities now acknowledge that COVID-19 spreads through aerosol particles that can linger in the air for hours – not just through larger droplets or soiled surfaces.

Suddenly it’s no mystery why COVID outbreaks have temporarily shuttered a number of Ohio schools or forced them into remote learning, just weeks into the academic calendar.

Indeed, life during the pandemic is all about risk management. So with the help of Dr. Amy Edwards, an infectious disease specialist at University Hospitals, cleveland.com and The Plain Dealer have considered the following eight components of an average school day, ranked from lowest to highest risk of COVID-19 exposure.

8. Recess

Edwards encourages schools to treat more parts of the school day like outdoor recess, allowing children to spend as much time outside as possible, where there is a very low risk of COVID-19 transmission because of natural ventilation.

“Of course, there have been cases of outdoor transmission but it’s pretty rare,” Edwards said. “But if you’re doing quiet reading time, or any kind of instruction that can be done in a less structured environment, outdoors in order to minimize risks, it’s been found to be hugely successful.”

According to the National COVID-19 Outdoor Learning Initiative, outdoor schooling can reduce respiratory transmission, reduce contact transmission, improve physiological outcomes and mental health.

It’s still important to maintain distance between students, when possible, especially among those who are unvaccinated and while taking part in physical activities.

7. Hallways and lockers

Time spent in school hallways or at lockers is considered one of the lower risk parts of the school day, according to Edwards, because students and staff spend relatively little time in the space. And typically, there is more ventilation in hallways than many other school building locations.

“In general, if everything is big, open and has good air flow, the risk is lower,” Edwards said. “The more closed off something is, there is less air flow and a higher risk.”

To help further mitigate risks in hallways, MayoClinic recommends schools create one-way traffic patterns and reconfigure locker setup, grouping lockers together by student classrooms.

6. Restrooms

Between the short amount of time spent in restrooms and the automatic separation that restroom stalls provide, Edwards classifies restroom breaks as a relatively low-risk part of a student’s day.

“If it’s a cramped and small restroom with very poor air circulation, you could, in theory, see a situation where somebody went in who has COVID-19, had a coughing fit generating a lot of aerosols, left and somebody else came in and breathed those in, but that’s pretty unlikely,” Edwards said.

Aerosol particles can remain in the air for up to three hours, however the longer they linger, the more they’re diluted as they mix with other air in the space. Schools can reduce risk in bathrooms by limiting occupancy and frequently cleaning high-touch surfaces.

5. Sports

Assigning risk to sports depends on which sport is being played and what playing conditions are present, which puts these physical activities in the middle of the list.

Sports like swimming and track, where there isn’t close contact, will have a lower risk than a high contact sport such as wrestling, according to Edwards. Outdoor sports like football are afforded the luxury of natural ventilation, whereas indoor basketball will rely on the ventilation system installed in the building.

One of the biggest risks for sports comes from the increase in heavy breathing, which produces more droplets and aerosols, two ways in which COVID-19 is spread.

4. Bus

Edwards classifies the bus as a medium-level exposure threat. To keep kids safe while riding a school bus, she urges everyone to be masked and drivers to keep windows open.

“If the windows are open that can mitigate a lot of that risk,” Edwards said. “But of course, in Cleveland, how many more months are we going to be able to have kids on the bus with the windows open?”

Without proper ventilation, droplet and aerosol transmission can occur. The highest risk for droplet transmission is to those sitting closest to a student with COVID-19. In cases of a long bus ride and closed windows, conditions could allow for aerosol transmission as well.

“The nice thing about school buses is it’s generally a short ride,” Edwards said. “I think droplets are going to be the primary driver of outbreaks on buses. That’s why masking and not going to school if you’re sick or have symptoms is a big deal.”

The CDC recommends that drivers have spare masks on hand, install physical barriers between drivers and students, limit the number of students on the bus, provide hand sanitizer and disinfect frequently touched surfaces after each bus use.

3. Classroom

Similar to buses, or any confined space, the key to keeping classrooms safe are masks and ventilation. Teachers can reduce the risk of droplet transmission by making sure everyone in the room is masked and by moving desks farther apart. Teachers can increase ventilation naturally by opening doors and windows, or by using mechanical ventilation systems.

MayoClinic recommends spacing out desks and having them all face the same direction. Echoing recommendations from the CDC and World Health Organization, MayoClinic urges mask use, especially when social distancing is difficult to maintain. Parents can help maximize mask benefits by providing a clean back-up mask each day, labeling masks with their child’s name, sending a resealable bag to store masks when not in use and teaching proper mask practices at home.

The three most important qualities of an effective mask for children are comfort, the correct fit and a filtration system, said Linsey Marr, engineering professor at Virginia Tech during a Speak Up America virtual panel discussion on COVID-19 and schools. She cautions against children wearing N95 masks because they’re designed to fit adults. Instead, she encourages double masking, cloth masks with filtration layers and KN95 and KF94 masks, which offer designs for children.

The CDC suggests increasing air flow by moving workspaces to the most ventilated parts of a building or opening windows and doors for more natural ventilation, using fans to increase effectiveness. Schools can also consider installing filtration systems and using mechanical ventilation systems that bring fresh, outdoor air inside.

2. Lunch

“Lunch is probably one of the major risk points for kids during the day,” Edwards said. “Students are eating, laughing and generating tons of droplets and aerosols while not wearing masks.”

Schools have implemented different policies to mitigate lunchtime risks such as splitting up lunch groups between the cafeteria and classrooms and encouraging students to eat outside.

Healthychildren.org, powered by the American Academy of Pediatrics, suggests students eat lunch at their desks or in small groups, avoiding crowded lunchrooms. It’s especially important to keep unvaccinated students six feet apart when eating, since masks will be off. And as always, any measure to increase ventilation will help reduce the risk of aerosol transmission.

1. Choir

Like the lunchroom, choir is another part of the school day that brings a high risk of COVID-19 exposure. Singing is a forceful activity which tends to generate a high number of infectious aerosols.

“There are a number of documented super spreader events, both in the United States and around the world, linked to some sort of choir,” Edwards said. “I would see that as a fairly large risk point.”

Of the 61 people who attended a choir practice in Washington at the start of the pandemic, 53 cases were identified and two individuals died from COVID-19. A CDC investigation revealed that the 2.5-hour practice served as an opportunity for droplet transmission because of close contact, surface transmission from high-touch surfaces and aerosol transmission through singing, which can emit more small droplet particles than other activities.