Predicted Aerosol Aspiration Efficiency for Infants, Children, and Adults

Abstract

A two-dimensional viscous numerical model has been used to predict aerosol aspiration efficiency for human heads of three sizes facing the wind. This model used a geometrically simple cylindrical sampler to examine the effect of age (2, 10, or 18 years) on the aerosol aspiration efficiency for humans at three levels of exertion: low activity, light exertion, and high exertion. To validate the simple sampler model of the human head, cases were run that could be compared to published data on aspiration efficiency obtained with facially realistic mannequins. The satisfactory agreement between our model predictions and the published data supported the simple sampler simulation model. The model found that predicted aspiration efficiency increases with decreasing age and that the age-related effect on aspiration efficiency increases as particle size increases. Although the predicted effect of age on aerosol aspiration efficiency is not enormous, it can be significant for particles larger than about 50 μm in diameter. For example, the aspiration efficiency of 100 μm particles is predicted to be 60 percent higher for a 2-year-old than for an adult.