Development of a sampler to estimate regional deposition of aerosol in the human respiratory tract

A multistage sampler was developed and tested to estimate regional deposition of aerosol in the human respiratory system. The motivation for this research is to improve our ability to estimate inhaled aerosol dose. Current methods for aerosol measurement and exposure/risk assessment are based on particle aspiration (e.g. inhalable PM) or on penetration to various regions of the respiratory system (e.g. PM10). The sampler developed here operates at 1 m3 h-1 (16.7 l min-1) of flow and utilizes several substrates, connected in series, to mimic regional particle deposition. Two sets of polyurethane foam substrates are used to mimic particle deposition in the head airways and tracheobronchial regions, respectively. Particle deposition in the alveolar region is mimicked using diffusion screens. These substrates are amenable to trace chemical analyses but not gravimetric analyses, due to water vapor uptake with small changes in relative humidity.