Journal of the Royal Society, Interface
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Respiratory infections can be spread via 'contact' with droplets from expiratory activities such as talking, coughing and sneezing, and also from aerosol-generating clinical procedures. Droplet sizes predominately determine the times they can remain airborne, the possibility of spread of infectious diseases and thus the strategies for controlling the infections. While significant inconsistencies exist between the existing measured data on respiratory droplets generated during expiratory activities, a food dye was used in the mouth during measurements of large droplets, which made the expiratory activities 'unnatural'. ⋯ Considerable subject variability was observed and the average size of droplets captured using glass slides and microscope was about 50-100 microm. Smaller droplets were also detected by the aerosol spectrometer. More droplets seemed to be generated when a food dye was used.