海湾扇贝对柴油的富集与消除规律

采用半静态动力学富集实验方法,分别以石油烃、多环芳烃及含硫芳烃、烷烃为指标,通过分析海湾扇贝(Argopecten irradians)对轻柴油(–10#柴油)、重柴油的富集与消除规律,探讨柴油污染对海湾扇贝食用安全性的影响。实验结果表明:海湾扇贝体内石油烃、多环芳烃及含硫芳烃、烷烃含量与富集时间及水中石油烃浓度呈正相关。海湾扇贝不同组织对柴油的富集能力不同,累积量由高到低依次是内脏外套膜及鳃等其他组织闭壳肌。海湾扇贝对柴油的富集量与柴油的种类有关,相同条件下海湾扇贝对重柴油的富集量更高且消除速率比轻柴油慢,说明重柴油溢油污染对贝类质量安全的危害更大,更值得关注。受污染的扇贝移入清洁的海水中,体内的石油烃可以逐渐消除,消除速度要慢于富集速度。海湾扇贝对烷烃的富集倍数比多环芳烃低,消除速率比多环芳烃要快。海湾扇贝体内石油烃的消除主要是烷烃的贡献。受污染的海湾扇贝体内多环芳烃以2~3环为主,其消除速率比高环数多环芳烃快。受污染的海湾扇贝移入清洁的海水中,短时间内虽然石油烃残留量能下降至正常水平,但多环芳烃(尤其是高环数多环芳烃)残留仍会存在。因此建议在发生石油污染后,跟踪监测不仅要关注海水中石油烃,更要关注贝类体内石油烃,要将多环芳烃与石油烃的检测结果综合考虑。此外,出于食品安全考虑,食用扇贝时尽量去除内脏。

Accumulation and elimination of diesel in scallop Argopecten irradians

The aim of this study was to investigate the safety of the consumption of scallops exposed to diesel pollution, so as to provide basic information for the evaluation of the effects of oil pollution on the food safety of marine shellfish. The accumulation and elimination characteristics of scallops (Argopecten irradians) to diesel were explored using the semi-static dynamic test in the present study. Scallops were exposed to light (–10#) and heavy diesel. After a certain period of time, the scallops were placed in uncontaminated seawater. The content of petroleum hydrocarbon, polycyclic aromatic hydrocarbons (PAHs), and polycyclic aromatic sulfur heterocycles (PASHs), as well as alkanes, in water and scallop tissue at different times was determined by gas chromatography mass spectrometry. The results obtained are as follows: The content of petroleum hydrocarbon, PAHs and PASHs, as well as alkanes, in the scallop tissue was positively associated with the accumulation time and the petroleum hydrocarbon concentrations in water. Different tissues accumulated diesel to differing extents with accumulation being higher in the viscera than in the mantle and higher in the gills and other organs than in the adductor muscle. The accumulation ability of diesels in scallops was also related to the type of diesel. Under the same conditions, the scallop accumulated more heavy diesel than light diesel, while they eliminated heavy diesel more slowly than light diesel. Thus, heavy diesel pollution is more harmful to the quality and safety of shellfish and deserves more attention. When placed in uncontaminated water, the contaminated scallops could gradually eliminate petroleum hydrocarbons accumulated in the body, but the elimination was slower than the accumulation. The bioconcentra-tion factor of alkane was lower than that of PAHs, and alkane in scallops was therefore eliminated faster than PAHs were. However, alkane is the main component of diesels. Thus, the elimination of petroleum hydrocarbon by scallops was mainly because of the elimination of alkane. The low-molecular-weight PAHs (comprising 2–3 aro-matic rings) were dominant in the PAHs of contaminated scallops, and they were eliminated faster than high-molecular-weight PAHs (comprising 4–7 aromatic rings). When the contaminated scallops were placed in clean water, the petroleum hydrocarbons residue in the scallops returned to normal levels in a short time, but PAH residues (especially with four or more aromatic rings) remained for a long time. On the basis of the above results, we suggest that petroleum hydrocarbons in shellfish be monitored along with that in the water after an oil spill, and the PAHs residue also be taken into consideration. In addition, in the interest of food safety, the viscera of scallops should be discarded.