LAUSR

Background Evaluation of the performance of a whole-body human dust exposure chamber is presented in this report. Methods The volume of the chamber is 2.13 m3 and it is operated at a flow rate of 1.0 m3/min. Makeup and exhaust air were filtered. A Wright Dust Feeder was used to generate fly ash, the testing agent. An elutriator was used to maintain particles in the respirable range. A Rupprecht and Patashnick PM-10 TEOM, a direct reading instrument, was used to monitor particle concentration. Particle size distributions were determined by a QCM cascade impactor. The evenness of dust concentrations in the chamber was determined gravimetrically. Results Dust concentrations measured at different points within the chamber were associated with variability less than 10%. Dust concentrations measured by the TEOM, in μg/m3, at 0.2, 0.4, 0.8 and 1.6 RPMs of the Wright Dust Feeder, were 110 ± 2.8, 173 ± 8.5, 398 ± 20 and 550 ± 17, respectively. Particle size distributions (MMD and GSD) were 1.27 μm and 2.35, 1.39 and 2.22, 1.46 and 2.08, 1.15 and 2.2, respectively. Total dust concentrations measured gravimetrically in μg/m3, were 135 ± 21, 200 ± 35, 333 ± 18 and 891 ± 27, respectively. Conclusion The whole-body human exposure chamber offers several advantages and has better performance than most of the inhalation challenge systems previously described.