AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Comparison of Two PM Inlets for Improved Airborne lead Sampling
QUENTIN MALLOY, Andrew Dart, Jonathan Thornburg, Robert Vanderpool, April Corbett, RTI International
Abstract Number: 476 Working Group: Instrumentation and Methods
Abstract The High Volume Total Suspended Particulate (TSP) sampler, currently deployed by the US EPA, has long been recognized as a hindrance to accurate and precise assessment of ambient exposure for the Pb NAAQS. Long-standing limitations of this method include variations in size-selective performance (cutpoint and slope) as a function of wind-speed and direction, variable sampler dimensions and flow rates, poor precision, particle collection during non-sampling periods, and the filter's lack of suitability for conducting multi-element analysis and/or using other analytical techniques (e.g., XRF) The goal of this research is to determine size selective performance of candidate Total Suspended Particulate (TSP) samplers as a function of particle size and wind speed.
A low volume TSP (LVTSP) and an EPA dichotomous sampler (EPA TSP) with the internal fractionation stages removed were challenged at wind speeds of 2, 8 and 24 km/hr with 5, 10, 15 and 20 micrometer diameter particles. An Isokinetic sampler was utilized as the reference sampler. At 24 km/hr, the LVTSP consistently displayed lower efficiency than the EPA TSP sampler when compared to the reference inlet with average efficiencies of 21.7% as compared to 69.1% across all particle sizes tested. This pattern remained at wind speeds of 8 and 2 km/hr as well. It is worth noting however, the EPA TSP inlet several times reported efficiencies over 100%.