washington scientists have known for several months the new coronavirus can become suspended in microdroplets expelled by patients when they speak and breathe but until now there was no proof that these tiny particles are infectiousa new study by scientists at the university of nebraska that was uploaded to a medical preprint site this week has shown for the first time that sarscov2 taken from microdroplets defined as under five microns can replicate in lab conditionsthis boosts the hypothesis that normal speaking and breathing not just coughing and sneezing are responsible for spreading covid19 and that infectious doses of the virus can travel distances far greater than the six feet two meters urged by social distancing guidelinesthe results are still considered preliminary and have not yet appeared in a peerreviewed journal which would lend more credibility to the methods devised by the scientiststhe paper was posted to the medrxivorg website where most cuttingedge research during the pandemic has first been made publicthe same team wrote a paper in march showing that the virus remains airborne in the rooms of hospitalized covid19 patients and this study will soon be published in a journal according to the lead authorit is actually fairly difficult to collect the samples joshua santarpia an associate professor at the university of nebraska medical center told afpthe team used a device the size of a cell phone for the purpose but the concentrations are typically very low your chances of recovering material are smallthe scientists took air samples from five rooms of bedridden patients at a height of about a foot 30 centimeters over the foot of their bedsthe patients were talking which produces microdroplets that become suspended in the air for several hours in what is referred to as an aerosol and some were coughingthe team managed to collect microdroplets as small as one micron in diameterthey then placed these samples into a culture to make them grow finding that three of the 18 samples tested were able to replicatefor santarpia this represents proof that microdroplets which also travel much greater distances than big droplets are capable of infecting peopleit is replicated in cell culture and therefore infectious he saidthe potential for microdroplet transmission of the coronavirus was at one stage thought to be improbable by health authorities across the worldlater scientists began to change their mind and acknowledge it may be a possibility which is the rationale for universal maskingthe world health organization was among the last to shift its position doing so on july 7i feel like the debate has become more political than scientific said santarpiai think most scientists that work on infectious diseases agree that theres likely an airborne component though we may quibble over how largelinsey marr a professor at virginia tech who is a leading expert on aerial transmission of viruses and wasnt involved in the study said it was rare to obtain measurements of the amount of virus present in airbased on what we know about other diseases and