The current physical distancing guidelines provided by the World Health Organisation (WHO) and by the US Centers for Disease Control and Prevention (CDC) may not be adequate to curb the coronavirus spread, according to a research which says the gas cloud from a cough or sneeze may help virus particles travel up to 8 metres. The research, published in the Journal of the American Medical Association, noted that the the current guidelines issued by the WHO and CDC are based on outdated models from the 1930s of how gas clouds from a cough, sneeze, or exhalation spread.
Study author, MIT associate professor Lydia Bourouiba, warned that droplets of all sizes can travel 23 to 27 feet, or 7-8 metres, carrying the pathogen.
According to Bourouiba, the current guidelines are based on "arbitrary" assumptions of droplet size, "overly simplified", and "may limit the effectiveness of the proposed interventions" against the deadly pandemic.
She explained that the old guidelines assume droplets to be one of two categories, small or large, taking short-range semi-ballistic trajectories when a person exhales, coughs, or sneezes.
However based on more recent discoveries, the MIT scientist said, sneezes and coughs are made of a puff cloud that carries ambient air, transporting within it clusters of droplets of a wide range of sizes.
Bourouiba warned that this puff cloud, with ambient air entrapped in it, can offer the droplets moisture and warmth that can prevent it from evaporation in the outer environment.
"The locally moist and warm atmosphere within the turbulent gas cloud allows the contained droplets to evade evaporation for much longer than occurs with isolated droplets," she said.
"Under these conditions, the lifetime of a droplet could be considerably extended by a factor of up to 1000, from a fraction of a second to minutes," the researcher explained in the study.
The MIT scientist, who has researched the dynamics of coughs and sneezes for years, added that these droplets settle along the trajectory of a cough or sneeze contaminating surfaces, with their residues staying suspended in the air for hours.
"Even when maximum containment policies were enforced, the rapid international spread of COVID-19 suggests that using arbitrary droplet size cutoffs may not accurately reflect what actually occurs with respiratory emissions, possibly contributing to the ineffectiveness of some procedures used to limit the spread of respiratory disease," Bourouiba wrote in the study
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Haha ...when few mangaloreans who share cmon DNA with Isis and Pakistanis show open solidarity with Pakistan ..they cannot point at nationalist Indians. Papa same DNA share madidru naavu part of ummah chummah ..namma for father's Arab andru saha Saudi nalli ivakke mooji kaasda maryade tikkuji ..haha ...can any body who supports ummah can get citizenship in Saudi ? It means there are two types of DNA ..pure DNA and impure DNA. Hahaha....
Its very much understood that Muslim terrorists are using naxals and ulfa to spread their terror ..becoz they know if they directly engage ..boot licking khangress is not in power ...bjp don't want terror supporters vote and mercilessly it will crack down. ..Bholo Bharath mata ki jai
Shaji, that can not be done in Assam, since the DNA is same ..
Now china or Pak is going to get the blame, as the outsiders are held responsible for Train accidents in India.... Today one Train mishap was averted as the loco driver noticed a iron mould of 380 kilos on the track ......It will be a mystery how the mould of 380 kilos can be placed on railway tracks ....
why indian forces are not given special rights in Assam as they are given in kashmir
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