Development and evaluation of a personal particle sampler and a mobile high-capacity particle size classifier

Findings from health studies have raised concerns about the sufficiency of the National Ambient Air Quality Standards (NAAQS) of the United States for particulate matter, in terms of both its regulated level and its regulated species. These concerns have been difficult to address, since little is known about the relationship between health response and actual human exposure, which is determined by not only the ambient particle concentrations, but also by particle size, chemical composition, contributions from indoor sources, human time activity patterns, different geographic locations and accuracy of the sampling technology.; Two personal particle samplers, which operate at 4 l·min -1, with different cutpoints of 1.0 mum and 2.5 mum in aerodynamic diameter were developed and evaluated. These two samplers will be used in field studies in different locations of U.S. to provide better estimates of human exposure to particles of both accumulation mode and coarse mode. With proper design of the substrate the configuration and the appropriate choice for impaction material, both PPS are capable of providing a sharp cutpoint and low particle losses (less than 10%), independent of particle size. Particle bounce can be eliminated. The bounce-free, uncoated impaction substrate is a highly desirable feature for performing chemical analysis of collected PM.; The bounce free design of the PPS was scaled-up and applied to a new mobile High-Capacity Particle Size Classifier (HCPSC), which operates at 850 l·min-1 and collects three distinct PM fractions (coarse, fine and ultrafine modes). The HCPSC collects coarse and fine mode particles in high volume and on a small uncoated surface area of 14 cm 2, which can be extracted with small amount of solvent (5--10 ml) for performing toxicity studies and/or examining the aerosol physicochemical characteristics. Combination use of the PPS and HCPSC in a large scale field studies can provide useful information in the relationship between adverse health effects and actual human exposure.