TitlePAH and OPAH air-water flux and toxicity before, during and after shoreline oiling from the DWH Incident
Publication TypePoster
Year of Publication2014
AuthorsTidwell LG
Series EditorAnderson KA
Conference/Meeting/VenueSuperfund EAC
Date Published05/2014

Passive sampling devices were used to measure the air vapor phase and water dissolved phase at four Gulf of Mexico coastal sites. Sampling occurred prior to, during and after shoreline oiling concurrent with the Deepwater Horizon oil spill.  Measurements of 33 polycyclic aromatic hydrocarbons (PAHs) and 22 oxygenated PAHs (OPAHs) were taken across all time points and sites, and flux across the water/air boundary was determined.  While aqueous PAH concentrations have been previously reported, all air concentrations are some of the first to represent both vapor phase PAHs and OPAHs during the Deepwater Horizon incident.  The largest vapor phase Σ33airPAH concentrations in air were 24.1ng/m3 in Gulfport, MS during May 2010 and 22.7ng/m3 in Grand Isle, LA during June of the same year. The largest Σ22OPAH vapor phase concentrations in air were 26.6ng/m3 in Gulf Breeze, Florida during May 2010 and 20.6 in Gulfport, MS in May 2010.  Concentrations in May represented air data prior to shoreline oiling. The direction and magnitude of the time-integrated air-water exchange of 13 individual PAHs were strongly influenced by the Deepwater Horizon oil incident.  The largest Σ13 PAH volatilization was 11,200 ng/m2/day and occurred in Gulf Shores, AL in September 2010, with the largest individual PAH volatilization to air was acenapthene at a rate of 6,820ng/m2/day during the same deployment.  This work represent additional evidence of contamination during the Deepwater Horizon oil spill, but provides one of the first examples of flux determination with passive sampling data. In addition to impacting marine waters, the introduction of this volume of oil into this ecosystem combined with the combustion of this material had quantifiable impacts on Gulf of Mexico air chemistry and quality.