Guitart Carlos, Frickers Patricia, Horrillo-Caraballo Jose, Law Robin J, Readman James W
Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK.
Environ Sci Technol. 2008 Apr 1;42(7):2275-82. doi: 10.1021/es703125e.
A contamination survey was conducted after the beaching of the stricken cargo ship MSC Napoli in Lyme Bay on the south coast of Devon (UK). A grid of 22 coastal and offshore stations was sampled to investigate the extent of spilled oil and to screen for chemical contamination, as well as to evaluate the behavior of the oil at the air-sea interface. Samples were collected from the sea surface microlayer (SML) and from subsurface waters (SSW) at each station. The fuel oil spilled (IFO 380) was also analyzed. The determination of oil-related hydrocarbons (aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), terpanes, and steranes) and the screening for other harmful chemicals on the inventory of the MSC Napoli in the seawater samples, was performed by PTV-GC/ MS using large volume injection (LVI) techniques. Screening did not reveal the presence of any harmful chemicals other than petroleum-related compounds. Results afforded investigation of oil sources and spatial distributions of total PAH concentrations and enrichments in the sea surface microlayer (SML). Rather than a single source, oil fingerprinting analyses of the samples revealed a mixture of three types of oil: heavy fuel oil, lubricating oil, and a lighter oil (probably diesel oil). Enrichment factors (EF) in the SML (EF = C(SML)/C(SSW)) were calculated and, in the vicinity of the ship, approached 2000, declining with distance away from the wreck. These factors represent approximately a 1000-fold enrichment over typical coastal total PAH enrichments in the SML and reflected a clear petrogenic origin of the contamination (as demonstrated, for example, by a Fl/Pgamma ratio < 1). In addition, the spatial transport and fate (i.e., air-sea exchange processes and water column diffusion) of the oil-related hydrocarbons in the sea surface were investigated. Essentially, near the wreck, the SML was highly enriched in oil forming a visible sheen, both disrupting the normal air-seawater exchange processes and generating a downward diffusion flux of contaminants from the SML to the SSW. This was reflected by a higher occurrence of naphthalene relative to alkyl-naphthalenes in the SSW compared to the SML. The higher concentrations and different sources of oil found in the SML in comparison to those found in the SSW indicate that, if only subsurface water samples are investigated in isolation, the true extent and impact of a spill could be underestimated. It is important to simultaneously evaluate contamination in the sea surface during emergency response.
在英国德文郡南海岸莱姆湾，受损货船“MSC那不勒斯号”搁浅后进行了一次污染调查。在22个沿海和近海站点组成的网格区域进行了采样，以调查溢油范围、筛查化学污染，并评估油在海 - 气界面的行为。在每个站点从海表面微层（SML）和次表层水（SSW）采集了样本。还对泄漏的燃料油（IFO 380）进行了分析。通过使用大体积进样（LVI）技术的PTV - GC/MS对海水样本中与油相关的碳氢化合物（脂肪烃、多环芳烃（PAHs）、萜烷和甾烷）进行测定，并筛查“MSC那不勒斯号”清单上的其他有害化学物质。筛查未发现除石油相关化合物以外的任何有害化学物质。结果为调查油源以及海表面微层（SML）中总PAH浓度和富集的空间分布提供了依据。样本的油指纹分析显示，不是单一来源，而是三种油的混合物：重质燃料油、润滑油和一种较轻的油（可能是柴油）。计算了SML中的富集因子（EF = C(SML)/C(SSW)），在船附近该值接近2000，并随着远离残骸而下降。这些因子表示相对于SML中典型的沿海总PAH富集约有1000倍的富集，并反映了污染明显的石油成因（例如，通过Fl/Pgamma比值<1证明）。此外，还研究了海表面与油相关的碳氢化合物的空间输运和归宿（即海 - 气交换过程和水柱扩散）。本质上，在残骸附近，SML中油高度富集形成可见油膜，这既破坏了正常的海 - 水交换过程，又产生了从SML到SSW的污染物向下扩散通量。这表现为与SML相比，SSW中萘相对于烷基萘的出现频率更高。与SSW中发现的情况相比，SML中发现的油浓度更高且来源不同，这表明如果仅单独调查次表层水样本，溢油的真实范围和影响可能会被低估。在应急响应期间同时评估海表面的污染很重要。
