AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Airborne Biopolymer Analysis and Toxicity Potential Associated with Hydrocarbon Weathering on Shorelines Impacted by the Deepwater Horizon Oil Spill
ALINA M. HANDOREAN, Kevin McCabe, Jane Turner, Alison L. Ling, Benjamin J. Miller, Mark T. Hernandez, University of Colorado at Boulder
Abstract Number: 569 Working Group: Health Related Aerosols
Abstract The atmosphere carries biochemical hallmarks of life – both in primary and weathered forms. The contribution of the most primary biopolymers — DNA, lipids, carbohydrates and proteins — to the pool of atmospheric organic carbon associated with weathering oil, remains relatively unknown.
We investigated coastal aerobiological loads in conjunction with the petroleum hydrocarbon releases in the Gulf of Mexico, following the 2010 Deepwater Horizon accident. Airborne particulate matter was analyzed for its carbohydrate and DNA content, as well as its genotoxicity potential between contaminated beaches in Louisiana (Grand Isle), and geologically similar but pristine beaches on the eastern Texas Coast (Port Arthur). Size segregated aerosol samples (8 hour composites; PM2.5 and PM10) were collected with ultra-clean technique on filters mounted in teflon cassettes. Particulate matter was immediately eluted from these filters into sterile, pyrogen-free water, and aliquots stored for subsequent biopolymer, genetic and toxicity analyses.
Carbohydrates were measured using a sensitive colorimetric assay of phenol-conjugated monosaccharides. The mass and organic carbon fraction of these biopolymers was presented as a surrogate index for total bioaerosol loads, which was juxtaposed to the types of microorganisms present in air. Airborne genomic DNA was precipitated, amplified (PCR of 18s/16s RNA), sequenced and compared to the NCBI database for genus level identification.
Elevated levels of carbohydrates were observed in aerosols above oil contaminated beaches, with respect to their pristine counterparts. QIIME analysis resulted in a total of 14,925 sequences; patterns reveal variation in taxa abundance in the presence of weathering oil. Acinetobacter sp., and Legionella sp. were proeminent in many Louisiana aerosol samples. Flavobacteria were consistent in their distribution between both the sampling sites. A genetically engineered bacterial strain of Salmonella thyphimurium (TA 1535) exposed to filter eluents suggests that some aerosols collected above the Louisiana beaches had the potential to induce genotoxic cellular stresses.