AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
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Changes in the Single Particle Fluorescence of Biological Particles Exposed to Outdoor Environments and Their Relationship to the Atmospheric Chemistry
JOSHUA SANTARPIA, Sean Kinahan, Andres Sanchez, Don Collins, Yong-Le Pan, Steven Hill, Shanna Ratnesar-Shumate, Thomas Hawkyard, Sandia National Laboratories
Abstract Number: 493 Working Group: Single Aerosol Particle Studies - Techniques and Instrumentation
Abstract Biological aerosols are studied for many reasons, including their effects on cloud properties as both cloud condensation and ice nuclei. Predominantly, however, biological aerosols are studied because of their effects on human, plant and animal health. This can range from allergy to disease and is often concerned with the detection and measurement of bioaerosols used as biological weapons. Changes that occur to biological particles when exposed to certain ambient conditions have been shown to affect the ability to measure them through common techniques. Over the last several years, changes in biological particles exposed to ambient conditions in both Adelphi, MD and Houston, TX have been studied. In general, single particle fluorescence measurements have proven the most useful in understanding the chemistry affecting these particles. These studies are accomplished by seeding particles into a chamber exposed to ambient conditions for periods of several hours. The chambers used in this study employ a rotating drum constructed with an FEP Teflon film to allow sunlight to penetrate and an ePTFE membrane to allow ambient trace gases to permeate into the drum, while still containing the biological particles being studied. Biological aerosol particles were sampled with a TSI UV-APS (ex. 355 nm), a Single Particle Fluorescence Spectrometer (ex. 351 and 263 nm) an AGI-30 impinger and recently, a WIBS 4A. Collected aerosols were assayed for viability/infectivity and PCR. Solar intensity, relative humidity and ozone concentration were measured locally, and other meteorological data and air quality measurements were retrieved from local air quality monitoring sites. An aggregate of results and conclusions from these studies will be presented.