Characterizing airborne particulate matter during late-season soybean production using SEM/EDX automated single particle analyses and machine learning: A preliminary study in the Mississippi Delta

Authors: Moore, Matthew; Heintzman, Lucas; RAUSCH, JUANITA - Particle Vision; JARAMILLO-VOGEL, DAVID - Particle Vision; Locke, Martin

Submitted to: Bulletin of Environmental Contamination and Toxicology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2026
Publication Date: 5/18/2026
Citation: Moore, M.T., Heintzman, L.J., Rausch, J., Jaramillo-Vogel, D., Locke, M.A. 2026. Characterizing airborne particulate matter during late-season soybean production using SEM/EDX automated single particle analyses and machine learning: A preliminary study in the Mississippi Delta. Bulletin of Environmental Contamination and Toxicology. 116:102. https://doi.org/10.1007/s00128-026-04259-2.
DOI: https://doi.org/10.1007/s00128-026-04259-2

Interpretive Summary: Havesting crops and disking dry land can result in plumes of dust that cover large areas of agricultural land, even causing visibility problems on nearby roadways. We used novel technology to measure how much particulate matter was being transported in the air during these activities, as well as the origin of the particulate matter. Study results showed that agricultural activities just before harvest had a majority of organic sourced-particulate matter. After harvesting, the source of particulate matter shifted dramatically to mineral-sourced. Research is needed to examine the ecological and agronomic impact of particulate matter on crops and cropland, especially in the production-rich lower Mississippi River Basin.

Technical Abstract: The Mississippi Alluvial Plain (MAP) is an agriculturally intensive ecoregion, extending from southern Illinois to the Gulf shores of Louisiana. Airborne particulate matter (PM) may originate via resuspension from exposed agricultural field surfaces and agricultural activities during dry periods. These events may degrade local ecological conditions and cause dangerous situations on nearby roadways. Airborne PM may also originate from roadways and be transported into adjacent agricultural fields, the effects of which are poorly understood. A preliminary study assessing different sources of airborne PM was performed in Fall 2023, beginning two weeks before soybean harvest. Three passive air samplers were placed along the edge of a 101-ha field along US Highway 61, in Coahoma County, Mississippi, USA. Polished boron collection substrates were placed in each air sampler for sampling intervals of two-week each during specific agricultural production phases (pre-harvest; harvest; post-harvest disking; post-harvest hipping). Collected PM on boron substrates were analyzed by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM/EDX) automated single particle analysis (ASPA) combined with machine learning to identify morpho-chemical particle types and estimate concentrations of corresponding particle types in the size fractions PM80-10 and PM10-2.5. Results indicated that during pre-harvest, 56 wt. % of particulates (PM10-2.5) were biogenic/organic in nature, while 41 wt. % were minerals. During and after harvest, that ratio changed, with 36 wt.% of particulates (PM10-2.5) being biogenic/organic and 61 wt.% being minerals, specifically during harvest. Assays of elemental content indicated high concentrations of phosphorus (P), which were primarily biogenic and mineral in source. Our preliminary study demonstrates the need for inclusion of airborne PM investigations as part of ecological assessments of the potential impacts of intensive agricultural activities.