Slow the spread of the coronavirus this winter, according to a November 18, 2020 Washington Post opinion piece co-authored by Jopseph Allen, associate professor of exposure assessment science and director of the Healthy Buildings program at Havard T.H Chan School of Public Health.

The authors explained that humidity can affect virus transmission in three ways. Studies suggest that higherhumidity can enhance the body’s ability to flight off infection, that the coronavirus decays faster at close 60% relative humidity than at other levels; and that drier air can lead to greater numbers of tiny coronavirus particles that travel father and penetrate deeper into the lungs.

They noted that portable humidifiers can easily increase the relative humidity in homes, where coronavirus transmission frequently occurs. “As winter sets in, we need to defend our home, schools and offices,” the authors wrote. “In addition to other strategies – masks, distancing, ventilation and filtration – rasing the humidity is another layer of defense to consider.”