Ninety-five wild forage plants (belonging to 22 species of 18 families) and their corresponding rhizosphere soil samples were collected from wastelands of a large-scale abandoned Hg mining region for total Hg (THg) and methylmercury (MeHg) analysis. The forage plant communities on the wastelands were dominated by the Asteraceae, Crassulaceae, and Polygonaceae families. The THg and MeHg concentrations in the forage plants varied widely and were in the range of 0.10 to 13 mg/kg and 0.19 to 23 μg/kg, respectively. Shoots of Aster ageratoides showed the highest average THg concentration of 12 ± 1.1 mg/kg, while those of Aster subulatus had the highest average MeHg concentrations of 7.4 ± 6.1 μg/kg. Both the THg and MeHg concentrations in the aboveground plant parts exhibited positive correlations with the THg (r = 0.70, P < 0.01) and MeHg (r = 0.68, P < 0.01) concentrations in the roots; however, these were not correlated with the THg and MeHg concentrations in their rhizosphere soils. The species A. ageratoides, A. subulatus, and S. brachyotus showed strong accumulation of Hg and are of concern for herbivorous/omnivorous wildlife and feeding livestock. Taking the provisional tolerable weekly intake (PTWI) values for IHg recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA in Summary and conclusions of the seventy-second meeting of the joint FAO/WHO expert committee on food additives Rome, Italy, 2010) for human dietary exposure of 4 ng/g into account, the daily intake of IHg by a 65 kg animal grazing on 1.0 kg of forage (dry weight) would be between 190 and 13,200 μg, three to five orders of magnitude higher than the permitted limit, suggesting a potential risk of exposure.

从大规模废弃汞开采区的荒地中收集了九十五种野生饲草植物（属于18个科的22种）及其相应的根际土壤样品，以进行总Hg（THg）和甲基汞（MeHg）分析。荒地上的饲草植物群落以菊科，景天科和Poly科为主导。饲用植物中的THg和MeHg浓度差异很大，分别在0.10至13 mg / kg和0.19至23μg/ kg的范围内。Aster ageratoides的芽显示最高平均THg浓度为12±1.1 mg / kg，而Aster subulatus的平均THg浓度最高。具有最高的平均MeHg浓度为7.4±6.1μg/ kg。地上植物部分的THg和MeHg浓度均与根中THg（r  = 0.70，P  <0.01）和MeHg（r  = 0.68，P  <0.01）浓度呈正相关。然而，这些与根际土壤中的THg和MeHg浓度无关。物种A. ageratoides，A。subulatus和S. brachyotus表现出很强的Hg积累，是草食性/杂食性野生动物和饲养牲畜的关注点。取粮农组织/世卫组织食品添加剂联合专家委员会（JECFA在粮农组织/世卫组织食品添加剂联合专家委员会第七十二次会议摘要和结论中所建议的IHg的暂定每周耐受摄入量（PTWI）值（2010年），如果将人类饮食中4 ng / g的摄入量考虑在内，则以65千克动物饲喂1.0千克草料（干重）后每天摄入的IHg介于190和13,200μg之间，高出三到五个数量级超过允许的限值，表明存在潜在的暴露风险。