Virus Rain Is Pummeling Earth With Bacteria Every Day And Now We Finally Know Why
We're in the midst of the deadliest flu season in history, so just how much sickness is floating around in our atmosphere? Literally billions of viruses rain back to Earth every day, according to a shocking new study.
A new study in the journal Nature quantified the wet and dry deposition of free and attached viruses and bacteria at the Observatory high up on Spain's Veleta Peak and discovered that we're constantly being pummeled by microscopic bacteria raining from the sky. It's the first time that scientists have measured the number of viruses rising up from the Earth's surface into the free troposphere, the atmospheric layer that exists past our planet's weather systems but below the stratosphere where commercial airplanes fly.
"Every day, more than 800 million viruses are deposited per square meter above the planetary boundary layer—that's 25 viruses for each person in Canada," University of British Columbia virologist Curtis Suttle in a statement.
Suttle's discovery that these viruses can travel thousands of miles in the upper troposphere may explain why scientists find genetically identical strains in completely different parts of the world.
"Roughly 20 years ago we began finding genetically similar viruses occurring in very different environments around the globe," he said. "This preponderance of long-residence viruses traveling the atmosphere likely explains why—it's quite conceivable to have a virus swept up into the atmosphere on one continent and deposited on another." "The explanations for these observations are (1) that closely related microbes that can serve as host cells for these viruses must live in very different environments, (2) that the viruses must have very broad host ranges that allows them to infect distantly related hosts, or (3) that the dispersal of some viruses is so high that they are distributed globally," says the study.
What facilitates these viruses return back to our surface, though?
"Bacteria and viruses are typically deposited back to Earth via rain events and Saharan dust intrusions," said author and microbial ecologist Isabel Reche from the University of Granada. "However, the rain was less efficient removing viruses from the atmosphere."
If the story of a supervirus that travels thousands of miles through the air from a remote island to a densely populated city doesn't sound like a good movie plot, we don't know what does.