Development of an advanced personal nasal sampler (PNS) to access exposure to bioaerosols

Abstract

This research aimed to advance the development of a novel personal nasal sampler (PNS). PNS attaches to a user's nostrils and utilizes the user's breathing to capture airborne infectious agents on an advanced filter inside the PNS, thereby directly measuring actual personal exposure to those agents. Here, we designed, developed, and tested a hybrid filter (HF) to be used in PNS. The HF was designed by overlaying electrospun polyvinylidene fluoride (PVDF) nanofibers on a selected substrate for different durations. A suitable substrate was selected from meltblown and spunbond fabric filters of different densities, a MERV-5 carbon filter, and a pulmonary function test filter (PTF) based on their collection efficiencies and pressure drop. The candidate hybrid filters (HF) were then challenged with Arizona Road Dust particles aerosolized from a 2 % w/w slurry. The HF was 12.5 mm in diameter, corresponding to an average nostril diameter, and was operated at 5 and 10 L/min flow rates to simulate sedentary conditions and moderate exertion, respectively. The final HF showed collection efficiency of 60–70 % at 0.2–0.3 μm (most penetrating particle size) and >90 % for particles <0.05 μm and >0.7 μm. Its pressure drop was about 200 Pa. When challenged with enveloped bacteriophage Phi6, this HF showed recovery efficiencies of 99 % and 80 % at 5 and 10 L/min flow rates, respectively. In the next steps, the HF will be incorporated into a biocompatible holder and extensively tested in laboratory and field conditions for its ability to measure exposure to bioaerosols.