Tracheobronchial deposition predictions for infants, children and adolescents

It is believed that the regional deposition patterns for inhaled particles can be mathematically predicted for simple cases considering three mechanisms (impaction, sedimentation, and diffusion) along with anatomical and air flow information. We have performed calculations of tracheobronchial (TB) particle deposition for a human body mass range of 3.3 Kg to 70 Kg (birth to adulthood) over a range of ventilations. These calculations predict for most particle diameters between 0.01 and 10.0 µm and most states of physical activity, that smaller individuals will exhibit greater TB deposition efficiencies than larger individuals. When one considers the greater ventilation per Kg body mass for smaller people, it appears that the initial deposited TB dose for young children may often be well above that for the adult. © 1988 The British Occupational Hygiene Society