某关闭汞矿区附近农田蔬菜中的汞污染评价

Mercury pollution assessment for vegetables from a cropland near a closed mercury mine.

研究了某汞矿区附近蔬菜地的汞污染现状及其对周围居民的健康风险。通过汞矿区附近连片菜地所采集的15种蔬菜中总汞含量的分析发现，不同蔬菜的汞含量水平依次为叶菜类〉茄果类〉块茎类，其中叶菜类生菜的汞含量最高（57 mg·kg^-1），块茎类白萝卜的汞含量最低（1.67 mg·kg^-1）。对叶菜类和块茎类蔬菜不同部位的汞含量分析发现，同种蔬菜的不同部位对汞的富集能力不同。无论叶菜类还是块茎类，地上部分的汞含量均高于地下部分。其中，叶菜类蔬菜地上部分的外叶、内叶和混合叶的汞含量水平为外叶〉混合叶〉内叶。红萝卜和白萝卜各部位对汞的富集能力相似，即叶片〉萝卜表皮〉萝卜根。同时，对研究区中13个点位大气和土壤总汞含量分析表明，大气中总汞的含量在128～1109 ng·m^-3，土壤中总汞的含量水平为3.88～91.62 mg·kg^-1，均严重超标。通过对汞矿区居民摄入蔬菜的汞暴露评估与健康风险评价可知，单独蔬菜摄入不会危及附近居民健康，但若综合其他暴露途径，潜在健康风险较高。

Mercury pollution in 15 vegetable species collected from a cropland near a closed mercury mine and their health risk were assessed in this article. The results showed that the concentration of total mercury differed with vegetable species, with an order of leafy vegetables 〉 solanaceous vegetables 〉 tuber vegetables. Among the 15 vegetables, the concentration of total mercury in lettuce was the highest （57 mg·kg^-1）, whilst that in white radish was the lowest （1.67 mg·kg^-1）. For the leafy and tuber vegetables, the concentrations of total mercury differed greatly in different parts of vegetable. For six leafy vegetables and two tuber vegetables, the concentration of total mercury in aboveground part was higher than that in underground part. For six leafy vegetables, the concentrations of total mercury in outer part, central part and their mixture were in the order of outer 〉 mixture 〉 central. For the two tuber vegetables, the concentrations of total mercury in leaf, root and root skin were in the order of leaf 〉 root skin 〉 root. The concentrations of total mercury in air and soil were 128-1109 ng·m^-3 and 3.88-91.62 mg·kg^-1 respectively, indicating that both the air and soil in this area were polluted by mercury. The risk assessment indicated that eating vegetables alone did not pose a risk to health of the residents living in this area, but it might not be true if other mercury exposure pathways were comprehensively considered.