If you have a tendency towards being a hypochondriac, stop reading now.
Otherwise, consider this.
“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,” says UBC virologist Curtis Suttle.
Suttle was part of the first research project to quantify how many viruses are circulating around the earth’s atmosphere. It turns out there are billions.
They travel in soil dust, rain and sea spray. They know no boundaries as they make their way from earth up into the free troposphere, just below the stratosphere where where jets fly, and eventually make their way back down thousands of kilometres later.
“The viruses tend to hitch rides on smaller, lighter, organic particles in air and gas, meaning they can stay afloat in the atmosphere longer,” says a UBC press release about Suttle’s involvement in the research paper recently published in the International Society for Microbial Ecology Journal.
The researchers from UBC, the University of Granada and San Diego State University used platform sites high up in Spain’s Sierra Nevada mountains. They measured billions of viruses and tends of millions of bacteria being deposited every day. Viruses outnumbered bacteria at a rate that varied between nine and 461 times greater.
UBC says the researchers’ findings may explain why genetically identical viruses are often found in different environments around the globe.
So when someone sneezes in Vancouver, a genetically identical virus can find its way to Paris.
It was this ability to find the same viruses in many parts of the world that prompted the research. “This preponderance of long-residence viruses travelling 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.”
Viruses and bacteria are swept up in the atmosphere in small particles from soil-dust and sea spray. They typically fall back to earth during rain events and Saharan dust intrusions, says author and microbial ecologist Isabel Reche of the University of Grenada.
