An astonishing number of viruses are circulating around the Earth’s atmosphere – and falling from it – according to new research from scientists in Canada, Spain and the U.S.
The study marks the first time scientists have quantified the viruses being swept up from the Earth’s surface into the free troposphere, that layer of atmosphere beyond Earth’s weather systems but below the stratosphere where jet airplanes fly. The viruses can be carried thousands of kilometres there before being deposited back onto the Earth’s surface.
“Every day, more than 800 million viruses are deposited per square metre above the planetary boundary layer—that’s 25 viruses for each person in Canada,” said University of British Columbia virologist Curtis Suttle, one of the senior authors of a paper in the International Society for Microbial Ecology Journal that outlines the findings.