PARTICLE-SIZE DISTRIBUTION OF CATTLE FEEDLOT DUST EMISSION

The cattle feedlot industry is under increased scrutiny and regulatory involvement at state and national levels with regard to particulate m atter (PM) emissions from fugitive sources. Concentrations of total su spended particulate matter (TSP) and PM less than 10 micrometers (PM10 ) aerodynamic equivalent diameter (AED) were measured, using high volu me samplers and Sierra Andersen samplers, respectively. Particle size distributions of dust captured on sampler filters were measured with a Coulter Counter model TAII. Mass median diameters for high volume and PM10 samplers averaged 9.5 +/- 1.5 and 6.9 +/- 0.8 mu m (AED), respec tively. Three cattle feedlots (17,000 to 40,000 head capacity) in the Southern Great Plains were used in the study.