Scientists have gauged the viruses from the sky that are circulating in the Earth’s atmosphere. And the number is immense as hundreds of millions of bacteria and billions of viruses drop each day into the troposphere, which is the lowest layer of the atmosphere.
The study published in the International Society for Microbial Ecology Journal suggested that those viruses are swept up into the atmosphere in microparticles from soil-dust and sea spray. Scientists from the University of British Columbia led the study, according to Science Daily.
Curtis Suttle, a virologist and one of the senior authors of the study, said that over 800 million viruses are deposited per square meter above the planetary boundary layer each day. That is equivalent to 25 viruses for each person in Canada.
In the study, the scientists wanted to figure out the number of viruses that deposited to the height of 2,500 to 3,000 kilometers or about 1,550 to 1,860 miles. And they set up two collectors on platforms sites in the Sierra Nevada mountains in Spain. This area is known to be under the influence of a global dust belt, according to Science Alert.
After quantifying the viruses in the troposphere, the scientists discovered millions of bacteria and billions of viruses that were dropped per square meter each day in the free troposphere. The deposition rates for viruses were nine to 461 times larger than the deposition rates for bacteria.
Isabel Reche, the microbial ecologist from the University of Granada, said that bacteria and viruses are typically deposited back to Earth through rain events and Saharan dust intrusion. On the other hand, rain was less efficient removing viruses from the atmosphere.
The researchers think that these fluxes of bacteria and viruses from the atmosphere could affect the structure and function of recipient ecosystems. They further noted that rather than being a negative consequence, this deposition delivers a seed bank that could allow the ecosystems to adapt faster to environmental changes.
Viruses are not the only main cause of diseases or known as pathogens. There are viruses referred to as bacteriophages that could help humans by terminating destructive and damaging bacteria. The viruses also have a significant role in the ocean’s carbon cycle, according to Science Alert.