Some aspects of the airborne transmission of infection by Raymond P. Clark, and Mervyn L. de Calcina-Goff Interface Volume 6(Suppl 6):S767-S782 December 6, 2009 ©2009 by The Royal Society

(a) Thermal images showing the temperature map over the skin of two subjects at room temperature. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

(a) Schlieren photographs of the convective airstreams over a standing nude subject. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

Diagrammatic representation of the natural convective boundary layer flow generated over a subject in the standing, sitting and lying postures as visualized by the Schlieren technique. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

Schlieren photographs of an infant nursed in an incubator. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

(a) Scanning electron micrograph of skin scales nearly ready to be detached from the skin surface. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

Examples of the bellows action of operating theatre garments together with a Schlieren picture of the bellows effect at the bottom of an operating gown. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

Four assemblies graded according to bacterial dispersal and comfort. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

(a) Dramatic stroboscopic pictures showing the dispersal of droplets in a sneeze and (b) how this dispersal is attenuated by a cotton mask. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

(a) Drawings showing how expired air flow is modified when a mask is worn and a Schlieren photograph showing expired air flow around the mask. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

(a) The unique ‘hoverbed’ where the patient was levitated on a column of warm, sterile air. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

Variation of airborne bacterial concentration (assessed with a slit sampler) with time during a machine-cleaning period (8–28 min) in an operating theatre in (a) full, (b) half and (c) zero flow conditions. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

A Schlieren photograph showing the outflow from a deficient safety cabinet. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society

(a) A diagram of a laboratory, maintained at negative pressure that can be varied, with a double airlock entry. Raymond P. Clark, and Mervyn L. de Calcina-Goff J. R. Soc. Interface 2009;6:S767-S782 ©2009 by The Royal Society