Sources, Vertical Fluxes, and Equivalent Toxicity of Aromatic Hydrocarbons in Coastal Sediments of the Río de la Plata Estuary, Argentina
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- 作者：J. C. Colombo ; N. Cappelletti ; J. Lasci ; M. C. Migoya ; E. Speranza ; and C. N. Skorupka
- 刊名：Environmental Science & Technology
- 出版年：2006
- 出版时间：February 1, 2006
- 年：2006
- 卷：40
- 期：3
- 页码：734 - 740
- 全文大小：406K
- 年卷期：v.40,no.3(February 1, 2006)
- ISSN：1520-5851
文摘
Settling particles and bottom sediments collected at 1,2.5, and 4 km off the metropolitan Buenos Aires coast inthe Río de la Plata were analyzed to evaluate the sourcesand toxicity of resolved (PAHs) and unresolved (AROUCM)aromatic hydrocarbons. PAHs (0003-2.1 
ntities/mgr.gif">g g-1) and AROUCM(0.01-78 ntities/mgr.gif">g g-1) presented the highest concentrationsnear the Buenos Aires port and sewer and decreasing valuesup- and downstream and along on- and offshore gradients.Sediment traps deployed in the Central area revealedlarge aromatic fluxes (1.3 ± 1.5 and 31 ± 47 mg m-2 day-1for PAHs and AROUCM). The composition of sedimentaryPAHs was dominated by uniformly distributed highmolecular weight pyrogenic PAHs (53 ± 11% fluoranthene,pyrene, and heavier PAHs), followed by diageneticallyderived perylene more abundant in less polluted sites(29 ± 15%) and lower molecular weight petrogenic PAHs(18 ± 7.1% phenanthrene, anthracene, and methylatedcompounds), which covaried inversely with perylene. PAHdiagnostic ratios indicated a stronger influence ofpetrogenic discharges close to the shore and the prevalenceof combustion of fossil fuels and vehicle emissions overwood in offshore sediments. Sediment cores showedsustained hydrocarbon levels with decreasing proportionof petrogenic PAHs and relative enrichment of pyrogeniccomponents and perylene down to 20-cm depth. PAH toxicityassessment by sediment quality guidelines (SQG) and dioxin-equivalent factors (PAH TEQ: 0.08-395 pg g-1 dw)identified 1-2.5 km sediments close to the port and seweras the most affected area. According to SQG, dibenz[a,h]anthracene and pyrene were the most critical PAHs,followed by benzo[a]pyrene, benz[a]anthracene, and chrysene.In contrast, PAH TEQs were dominated by indeno[1,2,3-cd]pyrene, benzo[k]fluoranthene, benzo[a]pyrene, perylene,and benz[a]anthracene which accounted for an average86 ± 5.7% of total TEQs.
ntities/mgr.gif">g g-1) and AROUCM(0.01-78 ntities/mgr.gif">g g-1) presented the highest concentrationsnear the Buenos Aires port and sewer and decreasing valuesup- and downstream and along on- and offshore gradients.Sediment traps deployed in the Central area revealedlarge aromatic fluxes (1.3 ± 1.5 and 31 ± 47 mg m-2 day-1for PAHs and AROUCM). The composition of sedimentaryPAHs was dominated by uniformly distributed highmolecular weight pyrogenic PAHs (53 ± 11% fluoranthene,pyrene, and heavier PAHs), followed by diageneticallyderived perylene more abundant in less polluted sites(29 ± 15%) and lower molecular weight petrogenic PAHs(18 ± 7.1% phenanthrene, anthracene, and methylatedcompounds), which covaried inversely with perylene. PAHdiagnostic ratios indicated a stronger influence ofpetrogenic discharges close to the shore and the prevalenceof combustion of fossil fuels and vehicle emissions overwood in offshore sediments. Sediment cores showedsustained hydrocarbon levels with decreasing proportionof petrogenic PAHs and relative enrichment of pyrogeniccomponents and perylene down to 20-cm depth. PAH toxicityassessment by sediment quality guidelines (SQG) and dioxin-equivalent factors (PAH TEQ: 0.08-395 pg g-1 dw)identified 1-2.5 km sediments close to the port and seweras the most affected area. According to SQG, dibenz[a,h]anthracene and pyrene were the most critical PAHs,followed by benzo[a]pyrene, benz[a]anthracene, and chrysene.In contrast, PAH TEQs were dominated by indeno[1,2,3-cd]pyrene, benzo[k]fluoranthene, benzo[a]pyrene, perylene,and benz[a]anthracene which accounted for an average86 ± 5.7% of total TEQs.