CNR IGG, Istituto di Geoscienze e Georisorse, Via G. La Pira, 4, 50121 Firenze, Italy; Dipartimento di Scienze della Terra, Università di Firenze, Via G. La Pira, 4, 50121 Firenze, Italy.
CNR IGG, Istituto di Geoscienze e Georisorse, Via G. La Pira, 4, 50121 Firenze, Italy; Dipartimento di Scienze della Terra, Università di Firenze, Via G. La Pira, 4, 50121 Firenze, Italy.
Sci Total Environ. 2016 Nov 1;569-570:105-113. doi: 10.1016/j.scitotenv.2016.06.029. Epub 2016 Jun 21.
Tree barks are relevant interfaces between plants and the external environment, and can effectively retain airborne particles and elements at their surface. In this paper we have studied the distribution of mercury (Hg) in soils and in black pine (Pinus nigra) barks from the Mt. Amiata Hg district in southern Tuscany (Italy), where past Hg mining and present-day geothermal power plants affect local atmospheric Hg concentration, posing serious environmental concerns. Barks collected in heavily Hg-polluted areas of the district display the highest Hg concentration ever reported in literature (8.6mg/kg). In comparison, barks of the same species collected in local reference areas and near geothermal power plants show much lower (range 19-803μg/kg) concentrations; even lower concentrations are observed at a "blank" site near the city of Florence (5-98μg/kg). Results show a general decrease of Hg concentration from bark surface inwards, in accordance with a deposition of airborne Hg, with minor contribution from systemic uptake from soils. Preliminary results indicate that bark Hg concentrations are comparable with values reported for lichens in the same areas, suggesting that tree barks may represent an additional useful tool for biomonitoring of airborne Hg.
树皮是植物与外部环境的相关界面，可有效地在其表面保留空气中的颗粒和元素。本文研究了汞（Hg）在意大利托斯卡纳南部阿米亚塔山汞矿区土壤和黑云杉（Pinus nigra）树皮中的分布情况，过去的汞矿开采和现在的地热发电厂影响了当地大气汞浓度，引起了严重的环境问题。在该地区受汞污染严重的区域采集的树皮显示出文献中报道的最高汞浓度（8.6mg/kg）。相比之下，在当地参照区和地热发电厂附近采集的同种树皮的汞浓度要低得多（范围为 19-803μg/kg）；在佛罗伦萨市附近的“空白”地点，浓度甚至更低（5-98μg/kg）。结果表明，Hg 浓度从树皮表面向内部逐渐降低，与空气中 Hg 的沉积一致，土壤中系统性吸收的贡献较小。初步结果表明，树皮中的 Hg 浓度与同一地区地衣的报告值相当，这表明树皮可能是监测空气中 Hg 的另一种有用工具。
