According to a new study by Oregon researchers, flu viruses are more easily transmitted from one person to another when humidity levels are low. The researchers say that the idea of using a humidifier may prove helpful for many people in places where the influenza virus is more likely to pose serious threats.

“It seems that [the influenza virus'] ability to survive and be transmitted person-to-person is greatly affected by how dry or wet the air is,” says study co-author Jeffrey Shaman, Ph.D., of Oregon State University in Corvallis.

The researchers wanted to find out why the virus tends to spread more rapidly in some areas, while in others there is almost no flu activity. It appears that the situation has a lot to do with the level of humidity. When the level of humidity is low, influenza virus can survive for a long period of time and transmission rates go up.

For the study, the team used data from a 2007 Mount Sinai School of Medicine study. The previous study failed to identify a connection between absolute humidity and flu virus transmission and survival.

Taking into consideration the fact that relative humidity explains only about 36 percent of flu virus survival and 12 percent of transmission, while absolute humidity is linked to 90 percent of flu virus survival and 50 percent of transmission, the conclusion is unquestionable. But researchers still do not have a valid explanation for this phenomenon.

The findings are published in the journal the Proceedings of the National Academy of Sciences.