Concentrations and sources of polycyclic aromatic hydrocarbons in surface coastal sediments of the northern Gulf of Mexico

Geochemical Transactions

Research Article

Wei Wu¹  Zucheng Wang²  Kehui Xu³  Alexander S Kolker⁴  Zhanfei Liu⁵  Lawrence M Mayer⁶  Zulin Zhang⁷ 

[1] Department of Coastal Sciences, Gulf Coast Research Laboratory, The University of Southern Mississippi, 39564, Ocean Springs, MS, USA;Department of Geography, Northeast Normal University, Changchun, China;Marine Science Institute, The University of Texas at Austin, Port Aransas, TX, USA;Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, USA;Coastal Studies Institute, Louisiana State University, Baton Rouge, LA, USA;Louisiana Universities Marine Consortium, 70344, Chauvin, LA, USA;Marine Science Institute, The University of Texas at Austin, Port Aransas, TX, USA;School of Marine Sciences, University of Maine, 04573, Walpole, ME, USA;The James Hutton Institute, Aberdeen, UK;

关键词: Polycyclic aromatic hydrocarbons;    Grain size;    Surface area;    Organic carbon;    Principal component analysis;    Bioavailability;    Coastal sediments;    Northern Gulf of Mexico;   

DOI  :  10.1186/1467-4866-15-2

 received in 2013-09-03, accepted in 2014-03-10,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundCoastal sediments in the northern Gulf of Mexico have a high potential of being contaminated by petroleum hydrocarbons, such as polycyclic aromatic hydrocarbons (PAHs), due to extensive petroleum exploration and transportation activities. In this study we evaluated the spatial distribution and contamination sources of PAHs, as well as the bioavailable fraction in the bulk PAH pool, in surface marsh and shelf sediments (top 5 cm) of the northern Gulf of Mexico.ResultsPAH concentrations in this region ranged from 100 to 856 ng g−1, with the highest concentrations in Mississippi River mouth sediments followed by marsh sediments and then the lowest concentrations in shelf sediments. The PAH concentrations correlated positively with atomic C/N ratios of sedimentary organic matter (OM), suggesting that terrestrial OM preferentially sorbs PAHs relative to marine OM. PAHs with 2 rings were more abundant than those with 5–6 rings in continental shelf sediments, while the opposite was found in marsh sediments. This distribution pattern suggests different contamination sources between shelf and marsh sediments. Based on diagnostic ratios of PAH isomers and principal component analysis, shelf sediment PAHs were petrogenic and those from marsh sediments were pyrogenic. The proportions of bioavailable PAHs in total PAHs were low, ranging from 0.02% to 0.06%, with higher fractions found in marsh than shelf sediments.ConclusionPAH distribution and composition differences between marsh and shelf sediments were influenced by grain size, contamination sources, and the types of organic matter associated with PAHs. Concentrations of PAHs in the study area were below effects low-range, suggesting a low risk to organisms and limited transfer of PAHs into food web. From the source analysis, PAHs in shelf sediments mainly originated from direct petroleum contamination, while those in marsh sediments were from combustion of fossil fuels.

【 授权许可】

Unknown   
© Wang et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.