Polycyclic Aromatic Hydrocarbon (PAH) and Oxygenated PAH (OPAH) Air–Water Exchange during the Deepwater Horizon Oil Spill

Abstract

Passive sampling devices were used to measure air vapor and water dissolved phase concentrations of 33 polycyclic aromatic hydrocarbons (PAHs) and 22 oxygenated PAHs (OPAHs) at four Gulf of Mexico coastal sites prior to, during, and after shoreline oiling from the Deepwater Horizon oil spill (DWH). Measurements were taken at each site over a 13 month period, and flux across the water–air boundary was determined. This is the first report of vapor phase and flux of both PAHs and OPAHs during the DWH. Vapor phase sum PAH and OPAH concentrations ranged between 1 and 24 ng/m3 and 0.3 and 27 ng/m3, respectively. PAH and OPAH concentrations in air exhibited different spatial and temporal trends than in water, and air–water flux of 13 individual PAHs were strongly associated with the DWH incident. The largest PAH volatilizations occurred at the sites in Alabama and Mississippi in the summer, each nominally 10 000 ng/m2/day. Acenaphthene was the PAH with the highest observed volatilization rate of 6800 ng/m2/day in September 2010. This work represents additional evidence of the DWH incident contributing to air contamination, and provides one of the first quantitative air–water chemical flux determinations with passive sampling technology.

Impact of Natural Gas Extraction on PAH Levels in Ambient Air

“…Tidwell et al used LDPE passive samplers to measure PAHs on the shore during the Deepwater Horizon Incident in the U.S. Gulf of Mexico. At the two shoreline sites closest to the incident (Louisiana and Mississippi), average ΣPAH 14 were 6.3 ng/m 3 in observations immediately following the incident and 3.7 ng/m 3 in all subsequent observations over the following year 46 . All of these studies measured PAHs in the vapor phase, making results comparable.…”

“…Average sum of 14 PAHs, grouped by distance to the closest active natural gas well, with comparisons to previous studies 29, 44-46 . All data are vapor phase PAHs.…”

PAH and OPAH Flux during the Deepwater Horizon Incident

“…27 Vapor phase PAH and OPAH measured concentrations in air were corrected, as were the air-water flux mass exchange rates. Corrections were made due to the detection of an honest calculation error found in the original manuscript.…”

Transport stability of pesticides and PAHs sequestered in polyethylene passive sampling devices

“…LDPE passive samplers have been used to sample non-polar and semi-polar compounds in air (Paulik et al 2015; Tidwell et al 2015), water (Allan et al 2012; McDonough et al 2014), and sediment porewater (Fernandez et al 2014; Liu et al 2013). Contaminants diffuse into passive samplers, and concentrations increase until equilibrium is reached with the sampled matrix.…”