Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, United States.
Environ Sci Technol. 2010 Dec 1;44(23):9170-5. doi: 10.1021/es1024405. Epub 2010 Nov 4.
Carbon fullerenes, including buckminsterfullerene (C(60)), are increasingly available for numerous applications, thus increasing the likelihood of environmental release. This calls for information about their bioavailability and bioaccumulation potential. In this study, (14)C-labeled C(60) and (14)C-phenanthrene (positive control) were added separately to soils of varying composition and organic carbon content (OC), and their bioaccumulation in the earthworm Eisenia fetida was compared. Biota-sediment accumulation factors (BSAF) were measured after 24 h depuration in soils with high C(60) dosages (60, 100, and 300 mg-C(60) kg(-1) dry soil), which exceed the soil sorption capacity, as well as in soils with a low C(60) dose (0.25 mg kg(-1)) conducive to a high fraction of sorbed molecular C(60). The BSAF value for the low-dose soil (0.427) was 1 order of magnitude lower than for less hydrophobic phenanthrene (7.93), inconsistent with the equilibrium partition theory that suggests that BSAF should be constant and independent of the K(OW) value of the chemical. Apparently, the large molecular size of C(60) hinders uptake and bioaccumulation. Lower BSAF values (0.065-0.13) were measured for high-dose soils, indicating that C(60) bioaccumulates more readily when a higher fraction of molecular C(60) (rather than larger precipitates) is available. For the high-dose tests (heterogeneous C(60) system), soil OC content did not significantly affect the extent of C(60) bioaccumulation after 28 d of incubation, although higher OC content resulted in faster initial bioaccumulation. For low-dose soils, C(60) BSAF decreased with increasing soil OC, as commonly reported for hydrophobic chemicals due to partitioning into soil OC. There was no detectable transformation of (14)C(60) in either soil or worm tissue. Overall, the relatively low extent but rapid bioaccumulation of C(60) in E. fetida suggests the need for further studies on the potential for trophic transfer and biomagnification.
碳富勒烯，包括巴克敏斯特富勒烯（C(60)），由于其在许多应用中的可用性增加，从而增加了其向环境中释放的可能性。这就需要了解其生物利用度和生物累积潜力。在本研究中，分别将（14）C 标记的 C(60)和（14）C-菲（阳性对照）添加到具有不同组成和有机碳含量（OC）的土壤中，并比较了它们在蚯蚓（Eisenia fetida）中的生物累积情况。在高剂量（60、100 和 300 mg-C(60)kg(-1)干土）C(60)土壤中进行 24 小时净化后，测量了生物沉积物积累因子（BSAF），这超过了土壤的吸附能力，以及在低剂量（0.25 mg kg(-1))土壤中，有利于高比例的吸附分子 C(60)。低剂量土壤（0.427）的 BSAF 值比疏水性菲（7.93）低 1 个数量级，与平衡分配理论不一致，该理论表明 BSAF 应该是恒定的，并且与化学物质的 K(OW)值无关。显然，C(60)的大分子量阻碍了其吸收和生物累积。对于高剂量土壤，测量得到的 BSAF 值较低（0.065-0.13），这表明当更多的分子 C(60)（而不是较大的沉淀物）可用时，C(60)更容易生物累积。对于高剂量测试（异质 C(60)系统），尽管较高的 OC 含量会导致更快的初始生物累积，但在 28 天的孵育后，土壤 OC 含量并未显著影响 C(60)的生物累积程度。对于低剂量土壤，C(60)的 BSAF 随着土壤 OC 的增加而降低，这与疏水性化学物质通常报告的情况一致，这是由于它们分配到土壤 OC 中。在土壤或蚯蚓组织中均未检测到（14）C（60）的转化。总的来说，在 E. fetida 中，C(60)的生物累积程度相对较低，但生物累积速度较快，这表明需要进一步研究其在营养转移和生物放大方面的潜在风险。
