Improvement of Aerosol Distribution in Whole-Body Inhalation Exposure Chambers

Abstract

Uniform distribution of aerosol concentration in inhalation exposure chambers is important in the conduct of inhalation experiments. Several factors, including aerosol size, degree of mixing, and chamber design, may influence the aerosol distribution in whole-body exposure chambers. We report distributions in two types of Hazleton exposure chambers for different aerosol size and degree of mixing. To increase the mixing, a small fan was placed inside the chamber Without the fan, the spatial variation increased with aerodynamic particle size and reached 12% and 46% for 3.1-μm particles in Hazleton H2000 and H1000 chambers, respectively With the fan, the spatial variation was reduced to between 4% and 6% for particles in the size range of 7.6–3.7 μm. These data were obtained in chambers containing cage units, but without animals. Similar results were obtained with animals in the chamber.