Particle Size Effects on the Deposition Ratios of Airborne Particles in the Respiratory Tract

Particle size adjusting equipment was manufactured to determine the deposition ratio of airborne particles in the respiratory tract. This equipment is composed of an Andersen low-pressure impactor, one 100 l stainless steel tank, two filter holders, one Tedlar bag, one flow meter, and two pumps. We measured deposition ratios of benzo[a]pyrene (BaP) in size-fractionated particles in the respiratory tract using this equipment together with a Hans-Rudolph mask. BaP in particles was extracted using the sonication method and measured with the column concentration HPLC/spectrofluorometric detection method. BaP concentrations in PM0.52 (particles smaller than 0.52 μm) ranged from 0.025 to 0.193 ng/m3 (CV: 72%), and the CV of deposition ratios of BaP was 23%, (average 44.5%). Furthermore, we measured the deposition ratios of BaP in 6 different sized particles. While high deposition ratios of BaP were observed in PM3.9 air, PM2.5 air, and PM0.76 air, low deposition ratios were found in PM0.52 air, PM0.33 air, and PM0.13 air. We obtained similar results to the theoretical deposition ratio calculated from lung models.