The Sol-Air Laboratory: An Innovative Experimental Setup for Quantifying Airborne Biocontaminant Emissions from Field Agricultural Operations
Patrick Brassard, ARACELI DALILA LARIOS MARTÍNEZ, Stéphane Godbout, Laura Mila Saavedra, Angela Trivino Arevalo, Nathalie Turgeon, Valérie Létourneau, Mahsa Baghdadi, Caroline Duchaine, Research and Development Institute for the Agri-Environment
Abstract Number: 101
Working Group: Bioaerosols in Agriculture: Sources, Risks and Mitigation
Abstract
Dust, gases, odors, and bioaerosols, including aerosolized human and animal pathogens and antibiotic-resistant bacteria, may be emitted in significant quantities during agricultural activities, posing potential health risks. Evaluating exposure levels to airborne biocontaminants involves measuring concentrations at specified distances from emission sources. However, to determine the emission, airflow measurement is required which is impossible to evaluate in the field.
The Sol-Air laboratory was designed and built with the aim of measuring fugitive emissions from agricultural operations such as manure spreading. It comprises a greenhouse (8 m wide x 30 m long) covered with polycarbonate functioning as a large-scale wind tunnel. Two large inlets at one end and ten fans at the other ensure controlled airflow rates and velocities. Continuous monitoring of environmental conditions, including temperature, relative humidity, and wind speed, occurs at various points within the greenhouse. A large frame filled with loam soil simulates a field, while a watering system replicates rainfall.
Spreading experiments involving various manure types were conducted in the Sol-Air Laboratory using small-scale spreading equipment. The experimental setup allowed the measurement and comparison of fugitive emissions of particulate matter, gases (CH4, N2O, CO2 and NH3), odors and bioaerosols, collected on electret filter with high-volume air samplers installed in downwind position. Total bacteria, fecal indicators, and 38 different subtypes of antibiotic-resistant genes (ARGs) were quantified by qPCR.
Overall, the median emission rates of airborne biocontaminants during spreading were the highest for poultry manure, followed by cow manure, pig slurry spread with a dribble bar and with a splash plate, respectively. This study highlights how both the type of manure and spreading equipment can influence gas, particulate matter, odor, airborne bacteria and ARGs emission rates. For upcoming studies, soil tillage and pesticide spraying trials will be conducted in the Sol-Air laboratory to measure fugitive emissions from these activities.