The most dangerous aerosols are those that produce droplet nuclei (particles less than 5 [[micro]meter] in diameter).
Available data suggest that infectious droplet nuclei range in size from 1 to 5 [[micro]meter]; therefore, respirators used in health care settings should be able to filter the smallest particles in this range efficiently.
The susceptible exhales droplet nuclei into the air, to which target manikins are exposed.
From previous studies on interpersonal transport of droplet nuclei, relevant parameters range from droplet nuclei features, human (both susceptible and target) activity to indoor air distribution.
Airborne spread by droplet nuclei has sparked controversy, since true airborne transmission would best be controlled by isolating patients in rooms with negative air pressure and requiring staff to wear masks on entering the room.
The attack rate increased at low relative humidity, as would be expected, since virus suspended in aerosolized droplet nuclei survives much longer at lower humidity.
Infection occurs when a susceptible person inhales droplet nuclei
The size and duration of air-carriage of respiratory droplets and droplet nuclei.
On airborne infection (Study II): Droplets and droplet nuclei.
Small droplets may participate in short-range transmission, but they are more likely than larger droplets to evaporate to become droplet nuclei
and then be considered as having the potential for long-range airborne transmission.
Every time a person with incompletely treated or untreated TB of the lung or larynx coughs, sneezes, laughs, sings, or even talks, he or she emits airborne droplet nuclei
, 1 to 5 |micrometer~ in size.