BOSTON (CBS) – Experts from Harvard say they might have a simple solution for concerns over airflow in schools during the coronavirus pandemic – open windows and doors.

In an op-ed for the Washington Post, professors Joseph G. Allen and Jack Spengler and research associate Jose Cedeño-Laurent of the Harvard T.H. Chan School of Public Health wrote, “Opening windows sounds too simple to be true… But in this case, simplicity is elegant – grounded in science and risk-reduction principles.”

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The experts say that opening doors and windows could help stop the spread of the coronavirus by diluting virus particles that might be in the air.

“It’s the simplest and quickest way to increase the air-change rates,” they wrote. “The benefits of open windows extend to buses, too.”

Improving air quality in schools is a major issue in many towns this fall as districts choose between in-person, hybrid or remote learning.

The state’s largest teachers’ union, the Massachusetts Teachers Association, doesn’t believe it will be safe until school buildings are upgraded to improve air quality.

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On Monday, several teachers in Andover refused to enter schools during a professional development day because they were worried about the air quality inside the buildings. They went back inside Tuesday after the school committee threatened legal action.

The Coalition to Safely Reopen Schools, made up of parents, teachers and community activists from Massachusetts, issued a statement Monday about 16 different areas of concern, including “the proper ventilation and circulation of air.”

Those in favor of students returning to school at least part-time say other precautions, such as masks, social distancing and plastic shields should be enough for teachers and students.

Governor Charlie Baker said he’s against all Massachusetts schools starting fully remote because the data and science doesn’t support it. He said the vast majority of communities in Massachusetts have coronavirus transmission rates low enough to allow for in-person learning.

The Harvard researchers say if you’re going back to school, open those windows when you can.

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‘Opening windows now, in the so-called shoulder season when weather is mild, can buy schools time to make the permanent and necessary upgrades to ventilation systems before winter arrives,” they wrote.