Classroom Virus Spread: How Humidity Can Help

The COVID-19 pandemic taught us a lot about how diseases spread indoors. One big lesson was that crowded, poorly ventilated spaces can be hotspots for infection. Most classrooms in the U. S. don't have mechanical ventilation, so they can fill up with tiny virus particles in the air. Scientists used a safe virus called bacteriophage phi6 to study how well these airborne particles spread in classrooms without any natural or mechanical ventilation. They found that these virus-carrying particles can cause new infections quickly, no matter the distance.Interestingly, the length of exposure didn't change how easily the virus spread. What did make a difference was the humidity in the room. Higher humidity actually lowered the spread of the virus, while temperature and UV disinfection devices didn't make much difference. So, even without fancy ventilation systems, keeping the humidity up can be a simple and cheap way to reduce virus spread.