Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Co-operative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia.
Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan, NSW 2308, Australia; Co-operative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia.
Sci Total Environ. 2019 Nov 15;691:605-610. doi: 10.1016/j.scitotenv.2019.07.045. Epub 2019 Jul 4.
The potential for bioaccumulation and associated genotoxicity of nonextractable residues (NERs) of polycyclic aromatic hydrocarbon (PAHs) in long-term contaminated soils have not been investigated. Here we report research in which earthworms, Eisenia fetida, were exposed to a soil containing readily available benzo[a]pyrene (B[a]P) and highly sequestered B[a]P NERs aged in soil for 350 days. B[a]P bioaccumulation was assessed and DNA damage (as DNA single strand breaks) in earthworm coelomocytes were evaluated by comet assay. The concentrations of B[a]P in earthworm tissues were generally low, particularly when the soil contained highly sequestered B[a]P NERs, with biota-soil accumulation factors ranging from 0.6 to 0.8 kg/kg. The measurements related to genotoxicity, that is percentage (%) of DNA in the tails and olive tail moments, were significantly greater (p < 0.05) in the spiked soil containing readily available B[a]P than in soil that did not have added B[a]P. For example, for the soil initially spiked at 10 mg/kg, the percentage of DNA in the tails (29.2%) of coelomocytes after exposure of earthworms to B[a]P-contaminated soils and olive tail moments (17.6) were significantly greater (p < 0.05) than those of unspiked soils (19.6% and 7.0, for percentage of DNA in tail and olive tail moment, respectively). There were no significant (p > 0.05) differences in effects over the range of B[a]P concentrations (10 and 50 mg/kg soil) investigated. In contrast, DNA damage after exposure of earthworms to B[a]P NERs in soil did not differ from background DNA damage in the unspiked soil. These findings are useful in risk assessments as they can be applied to minimise uncertainties associated with the ecological health risks from exposure to highly sequestered PAH residues in long-term contaminated soils.
尚未研究多环芳烃（PAHs）不可提取残留（NER）在长期污染土壤中的生物累积潜力及其相关遗传毒性。在这里，我们报告了一项研究，其中将赤子爱胜蚓暴露于一种土壤中，该土壤中含有易获得的苯并[a]芘（B[a]P）和在土壤中老化 350 天的高度隔离的 B[a]P NER。通过彗星试验评估了 B[a]P 的生物累积，并评估了蚯蚓体腔细胞中的 DNA 损伤（作为 DNA 单链断裂）。蚯蚓组织中 B[a]P 的浓度通常较低，特别是当土壤中含有高度隔离的 B[a]P NER 时，生物群 - 土壤积累因子的范围为 0.6 至 0.8 kg/kg。与遗传毒性有关的测量值，即尾巴中的 DNA 百分比（%）和橄榄尾矩，在含有易获得的 B[a]P 的添加土壤中显着大于（p <0.05），而没有添加 B[a]P 的土壤。例如，对于最初在 10 mg/kg 时添加的土壤，暴露于 B[a]P 污染土壤后的蚯蚓体腔细胞中 DNA 的尾巴百分比（29.2%）和橄榄尾矩（17.6）明显大于（p <0.05）未添加土壤（分别为 19.6%和 7.0%）。在所研究的 B[a]P 浓度（10 和 50 mg/kg 土壤）范围内，没有观察到作用的显着差异（p> 0.05）。相比之下，暴露于土壤中 B[a]P NER 后的蚯蚓 DNA 损伤与未添加土壤中的背景 DNA 损伤没有差异。这些发现对于风险评估很有用，因为它们可以用于最小化与长期污染土壤中高度隔离的 PAH 残留对生态健康风险相关的不确定性。
