Comparing Two Novel Passive Sampling Methods to Characterize Bioaerosols Emissions From Agricultural Activities: Rutgers Electrostatic Passive Sampler (REPS) and Conifer Needles

SAMANTHA LECLERC, Gediminas Mainelis, Nathalie Turgeon, Florent Rossi, Kevin Dillon, Paul George, Marc Veillette, Caroline Duchaine, Université Laval

     Abstract Number: 151
     Working Group: Bioaerosols

Abstract
Background:
The REPS uses a polarized ferroelectric polymer film in a spiral configuration to capture charged bioaerosols, standing as a complementary technique to active air samplers. Conifers and, specifically, their needles bioaccumulate antibiotic resistance genes (ARGs) and can also be used for passive sampling. Thus, this project used these two passive sampling approaches to characterize bioaerosols emitted from agricultural activities and compare their performance to active air sampling methodologies for bioaerosol monitoring during continuous emissions from a swine barn and manure spreading activity.

Procedure:
For the barn emissions, air was collected 5 meters from the fan exhausts using a SASS active sampler. The REPS were placed near the closest spruce edges (10m) for 2 weeks. The experiment was repeated 4 times, and needles (15g) were systematically sampled. For manure spreading, the air was collected using both SASS and REPS samplers by following a spreader with a tractor. Additional air samples were collected near a cedar hedge, along with needles (15g). The experiment was repeated 5 times. DNA was extracted from samples and the concentrations of total bacteria (16S rRNA gene), pig indicators (an Aerococcus viridans phage and pig DNA) and 28 ARGs were assessed by qPCR/high-throughput qPCR. Results were compared to the bioaerosols at controls sites located six kilometers away from any agricultural influence.

Findings:
All samplers managed to capture airborne bacteria and the A. viridans phage with comparable efficiencies. However, pig DNA tended to be lower on the REPS than SASS and needles. All samplers showed similar ARG patterns. Overall, passive samplers, REPS and conifer needles, appeared to be more suitable for assessing continuous emissions than short-term emission events.

Implications:
The passive samplers displayed a strong potential to monitor bioaerosols emissions from agricultural facilities. Their efficiency to estimate emissions from other facilities, including poultry barns, will be evaluated.