Faculty of Environmental & Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100, Tsukide, Higashi-ku, Kumamoto, 862-8502, Japan; Hainan Provincial Center for Disease Control and Prevention, No.44, Haifu Road, Longhua district, Haikou city, Hainan Province, China.
Faculty of Environmental & Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100, Tsukide, Higashi-ku, Kumamoto, 862-8502, Japan.
Sci Total Environ. 2018 Sep 15;636:1565-1576. doi: 10.1016/j.scitotenv.2018.04.259. Epub 2018 May 21.
The contents and spatial distribution of mercury (Hg), including soil-Hg fractionation and Hg-containing native earthworm Bimastos parvus (B. parvus) species, were investigated in the leachate-contaminated zone of a large traditional landfill, Japan. Soil-Hg was fractionated into 5 categories: F1/water soluble Hg (Hg-w), F2/human stomach acid soluble Hg (Hg-h), F3/organic-chelated (Hg-o), F4/elemental Hg (Hg-e), and F5/mercuric sulfide (Hg-s). The total mercury (T-Hg) and methylmercury (MeHg) of native B. parvus, and the geochemical properties of soils were examined in this study. Soil T-Hg concentration ranged between 0.227 and 2.919 mg kg dry weight (dw). The T-Hg and MeHg concentrations of B. parvus species ranged from 1.242 to 6.775 mg kg dw and from 0.031 to 0.218 mg kg dw, respectively. Percentages of soil-Hg fractions were in the order of F3/Hg-o > F4/ Hg-e > F5/Hg-s > F1/Hg-w > F2/Hg-h, and the fractions of Hg-o and Hg-e were 55.50% and 35.31%, respectively. Similar distributions and close correlations between the levels of B. parvus Hg and soil Hg-o, Hg-e, and Hg-s were observed in this study. The distribution of Hg in B. parvus was associated with soil organic matter (SOM) content and particle size (sand, clay); however, it was not correlated with Hg-w or Hg-h. The results indicated that easily bioavailable and soluble Hg fractions (Hg-w, Hg-h) of the soil were not appropriate to illustrate the distribution of Hg in native B. parvus. Instead, the stable soil-Hg fractions (Hg-o, Hg-e, and Hg-s) demonstrated good relationships of spatial distribution with B. parvus Hg in leachate-contaminated soil. It is advisable to preclude the evaluation of Hg biological distribution using soluble Hg fractions only. Stable Hg fractions in leachate-contaminated soil should also be included for assessing the biological distribution of Hg in leachate-contaminated soils.
在日本一个大型传统垃圾填埋场的渗滤液污染区，调查了汞（Hg）的含量和空间分布，包括土壤-Hg 分级和含汞本地蚯蚓 Bimastos parvus（B. parvus）物种。土壤-Hg 分为 5 类：F1/水溶性 Hg（Hg-w）、F2/人类胃酸可溶 Hg（Hg-h）、F3/有机螯合（Hg-o）、F4/元素 Hg（Hg-e）和 F5/硫化汞（Hg-s）。本研究检测了本地 B. parvus 的总汞（T-Hg）和甲基汞（MeHg）以及土壤的地球化学性质。土壤 T-Hg 浓度范围为 0.227 至 2.919mg/kg 干重（dw）。B. parvus 物种的 T-Hg 和 MeHg 浓度范围分别为 1.242 至 6.775mg/kg dw 和 0.031 至 0.218mg/kg dw。土壤-Hg 分数的比例顺序为 F3/Hg-o>F4/Hg-e>F5/Hg-s>F1/Hg-w>F2/Hg-h，Hg-o 和 Hg-e 分数分别为 55.50%和 35.31%。本研究中观察到 B. parvus Hg 水平与土壤 Hg-o、Hg-e 和 Hg-s 之间存在相似的分布和密切的相关性。B. parvus 中 Hg 的分布与土壤有机质（SOM）含量和粒径（砂、粘土）有关；然而，它与 Hg-w 或 Hg-h 无关。结果表明，土壤中易生物利用和可溶性 Hg 分数（Hg-w、Hg-h）并不适合说明本地 B. parvus 中 Hg 的分布。相反，稳定的土壤-Hg 分数（Hg-o、Hg-e 和 Hg-s）与渗滤液污染土壤中 B. parvus Hg 的空间分布具有良好的关系。仅使用可溶性 Hg 分数评估 Hg 的生物分布是不可取的。还应包括渗滤液污染土壤中的稳定 Hg 分数，以评估渗滤液污染土壤中 Hg 的生物分布。
