title: Forensic implications of respiratory derived blood spatter distributions.
abstract: The nature of blood aerosols produced in physiological studies of an upright subject expiring small volumes through straws, spitting and mouthing sounds, and a semi-prone subject spitting through a bloody mouth or snorting through a single nasal orifice and by a simplified physical model of the respiratory system were investigated. Each manoeuvre produced many hundreds of droplets of a range of size, the vast majority being less than 1mm diameter. Droplets under 1mm dia. travelled over 1m - much further than could be expected if their flight was ballistic, like that of impact spatter. Respired blood aerosol properties are explained in terms of established mechanics of airflow shear induced aerosol production and the fluid mechanics of exhaled air movement.
authors.affiliation: Royal Brompton Hospital and National Heart & Lung Institute, Sidney Street, London SW3 6NT, United Kingdom. d.denison@rbht.nhs.uk
authors.forename: David
authors.initials: D
authors.lastname: Denison
authors.forename: Alice
authors.initials: A
authors.lastname: Porter
authors.forename: Matthew
authors.initials: M
authors.lastname: Mills
authors.forename: Robert C
authors.initials: RC
authors.lastname: Schroter
mesh_terms: D000054:Acceleration; D000388:Air; D055592:Biophysical Phenomena; D001769:Blood; D001801:Blood Stains; D045853:Exhalation; D006801:Humans; D008297:Male; D008954:Models, Biological; D009055:Mouth; D009666:Nose; D010316:Particle Size; D011187:Posture; D013060:Speech