Predicting PAH bioaccumulation and toxicity in earthworms exposed to manufactured gas plant soils with solid-phase microextraction
Predicting PAH bioaccumulation and toxicity in earthworms exposed to manufactured gas plant soils with solid-phase microextraction
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DOI：
10.1021/es070404s
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发表时间：
2007-11-01
影响因子：
11.4
通讯作者：
Hawthorne, Steven B.
中科院分区：
文献类型：
--
作者：
Jonker, Michiel T. O.;van der Heijden, Stephan A.;Hawthorne, Steven B.
以前的人工制气厂(MGP)的土壤经常受到多环芳烃(PAHs)的严重污染。目前依赖于多环芳烃总浓度的风险评估方法可能夸大了这种土壤的不利影响，因为生物有效性被忽视了。本研究应用固相微萃取技术(SPME)研究了15种MGP土壤对蚯蚓体内有效多环芳烃的浓度和毒性的影响。此外，还测定了多环芳烃在所有土壤上的吸附(K(Oc)值)。结果表明，K值有几个数量级的变化，表明通用有机碳归一化吸附系数在MGP站点通常会过于保守。SPME预测的生物积累量一般在测量生物积累量的10倍以内(在蚯蚓生物测定中)，而目前的风险评估模型估计高估了生物积累量10-10000倍。此外，根据估计的麻醉性多环芳烃的全身残留量，SPME在大多数情况下正确地预测了在生物检测期间观察到的蠕虫死亡率。对于当前风险评估程序表明存在问题的MGP站点，SPME因此为执行细化的特定站点评估提供了有用的工具。
Soils from former manufactured gas plant (MGP) sites are often heavily contaminated with polycyclic aromatic hydrocarbons (PAHs). Current risk assessment methods that rely on total PAH concentrations likely overstate adverse effects of such soils since bioavailability is ignored. In this study, solid-phase microextraction (SPME) was applied to estimate bioavailable PAH concentrations and toxicity in earthworms exposed to 15 MGP soils. In addition, PAH sorption to all soils (K(oc) values) was determined. The results showed a several orders of magnitude variation in K,, values, demonstrating that generic organic carbon-normalized sorption coefficients will typically be overconservative at MGP sites. SPME-predicted bioaccumulation generally was within a factor of 10 of measured bioaccumulation (in earthworm bioassays), in contrast to current risk assessment model estimates that overpredicted bioaccumulation 10-10 000 times. Furthermore, on the basis of estimated total body residues of narcotic PAHs, SPME correctly predicted worm mortality observed during bioassays in the majority of cases. For MGP sites where current risk assessment procedures indicate concerns, SPME thus provides a useful tool for performing a refined, site-specific assessment.