Novel Passive Sampler to Assess Personal Exposures to Airborne Biological Agents

Taewon Han, GEDIMINAS MAINELIS, Rutgers, The State University of New Jersey

     Abstract Number: 297
     Working Group: Bioaerosols

Abstract
We present the development and testing of a novel passive sampler capable of measuring personal exposures to airborne infectious agents, including individual viruses, virus-laden droplets, and virus-particle agglomerates. There are no passive personal bioaerosol samplers, and they offer obvious advantages over active methods – no need for pump and power supplies. We previously developed and applied a stationary Rutgers Electrostatic Passive Sampler (REPS), where airborne biological agents are captured on a specially configured poly(vinylidene fluoride) (PVDF) film. Here, we used the same concept and designed a personal version of the sampler that attaches to clothing within an individual’s breathing zone. Inside this personal sampler (P-REPS), the permanently polarized ferroelectric film PVDF is placed in a holder and wound in a spiral configuration so that the film surfaces with opposing polarization face one another and are spaced 2.25 mm apart to create a sufficiently strong electrostatic field between the layers. We built several P-REPS prototypes with a 35 mm-wide base but different heights (1 in and 0.5 in) and investigated particle elution protocols with varying elution volumes (10-70 mL). The capture efficiency of the P-REPS models was tested with Staphylococcus epidermidis in a vertical settling chamber against a 37 mm PTFE filter, and the microorganisms were determined by acridine orange epifluorescence microscopy and ATP methodology; P-REPS was also tested at 0 and 90 degrees to the vertical. The number of spores captured by the 1-inch P-REPS exceeded the number of particles collected by a settling filter by a factor of ~3, indicating the effectiveness of the passive electrostatic capture mechanism. Current testing of the P-REPS compares it against an active low-flow sampler in chamber studies when collecting multiple microorganisms. Overall, the concept shows great promise as another tool to measure exposure to airborne microorganisms.