Surface Microlayer Enrichment of Polycyclic Aromatic Hydrocarbons in Southern Chesapeake Bay

Abstract

Dissolved and particle-associated polycyclic aromatic hydrocarbons (PAHs) were measured in the surface microlayer (SM) of the York and Elizabeth River tributaries of Southern Chesapeake Bay throughout 1 year. Particle-associated PAH concentrations in the SM increased nonlinearly with total suspended particulate (TSP) levels, and a much more rapid rise in particulate PAHs with TSP was observed in the Elizabeth River vs the York River SM. The steep rise in particle-associated PAH concentrations along with observed nonequilibrium distributions of PAHs between the dissolved and particle phases in the Elizabeth River SM implies that atmospheric deposition of soot particles may be an important source of PAHs to this urban estuary. A significant relationship between dissolved PAHs and dissolved organic carbon (DOC) was also observed at the York River site, with the more hydrophilic PAHs exhibiting greater increases with DOC. PAHs were significantly enriched in the SM of both sites relative to the subsurface water concentrations. Particle-associated and dissolved phase enrichment factors were strongly influenced by wind speed at the Elizabeth River site; however, only particulate phase enrichment factors were dependent on wind speed at the York River site.

Comparison of polycyclic aromatic hydrocarbon distributions and sedimentary organic matter characteristics in contaminated, coastal sediments from Pensacola Bay, Florida

“…This trend is consistent with the hydrophobic nature and high affinity of PAHs for sedimentary organic matter (Liu & Dickhut, 1997). Interestingly, the lower molecular weight PAHs, namely naphthalene, acenaphthylene, acenaphthene and fluorene, are not detected at any of the three sites.…”

“…PAHs are especially problematic because they exhibit toxicity and mutagenicity at very low concentrations and have a high tendency to bind to natural organic matter, therefore impeding and often hindering remedial attempts. Typically, PAH concentrations in coastal waters are 10-1000 times lower than those found in sediments, with most of the PAHs residing in surface layers (Kucklick & Bidleman, 1994;Liu & Dickhut, 1997). Physical processes that result in the resuspension of surface sediments in the water column, such as bioturbation, may promote the release of PAHs into coastal waters (Schaffner, Dickhut, Mitra, Lay, & BrouwerRiel, 1997).…”

PCBs and PAHs in sea-surface microlayer and sub-surface water samples of the Venice Lagoon (Italy)

“…3b). By contrast, an evident preferential accumulation in sea-surface microlayer waters is observed for the Ôpartic-ulateÕ phase, despite the fact that EF values are lower than those reported by other authors (Cincinelli et al, 2001;Liu and Dickhut, 1997). It is useful to notice that at station 1 the highest EF for both ÔdissolvedÕ and ÔparticulateÕ phases are relative to samples collected when sun irradiation was lowest, probably related to the reduced photo-degradation that may occur in the sea-surface microlayer (Schroeder and Lane, 1988); however no particular seasonal trend can be deduced.…”

n-Alkanes, PAHs and surfactants in the sea surface microlayer and sea water samples of the Gerlache Inlet sea (Antarctica)

“…The lowest concentrations were observed for samples SML4 and SSW4, for both dissolved and particulate phases. In fact a strong wind speed was recorded during the sampling period [42]. Wind speed is the major factor, in comparison to temperature or solar irradiation, which influences both particulate and dissolved PAHs enrichments.…”