Characterization of the Morphology of Particulate Matter inside Farm Houses Located near Biosolids-Applied Agricultural Fields

Land application of biosolids to improve the fertility of agricultural land is very common in the United States. Bioaerosols are airborne particulate matter (PM) aerosolized during various agricultural processes such as preapplication preparation, disking, application, and postapplication management. In recent years, there has been concern about the health of people living near the application sites even though these processes have been going on for decades. The focus of this study is to characterize PM inside households located near fields where biosolids have been applied. The PM was collected inside five houses on eight polytetrafluoroethylene (PTFE) filter papers using the GRIMM 1.108 dust monitor. Physical characteristics of PM were analyzed using the scanning electron microscope (SEM). The morphological properties of particles such as diameter, area, perimeter, aspect ratio, and shape factor of particles were determined using Image J software for the images captured using SEM. It was observed that there were a majority of particles in the range of 2.5–5 μm on all filter papers except two. The average ${\mathrm{PM}}_{2.5}$ over eight filters was observed to be about 32%, while for the ranges of 2.5–5.0 and 5.0–10.0 μm the averages was about 38 and 20%, respectively. The PM 2.5 averages for smoking, nonsmoking, control houses, and study houses were observed to be 40.63, 28.86, 33.37, and 31.28%, respectively. The shape-factor distribution and shape-distribution results indicate that there were a higher percentage of agglomerates, which was followed by spherical and pentagonal shaped particles. It was estimated that on an average 37.79% of PM collected over all the eight filters were agglomerates while 28.28% were spherical in shape.