Department of Physics, Earth and Environmental Sciences and ‡Department of Life Sciences, University of Siena , 53100 Siena, Italy.
Environ Sci Technol. 2014;48(15):8754-9. doi: 10.1021/es500866k. Epub 2014 Jul 14.
The uptake kinetics of elemental gaseous Hg (Hg(0)) in three species of epiphytic lichens (Pseudevernia furfuracea, Evernia prunastri, and Xanthoria parietina) were investigated under four different Hg concentrations (10, 15, 30, and 45 μg/m(3)) and three different temperatures (10, 20, and 30 °C) with the aim of evaluating the lichen efficiency for Hg(0) accumulation and their potential use in the estimate of atmospheric concentrations of this metal in the field. The results showed that under our experimental conditions the lichens accumulated Hg according to exposure time and that the metal is not released back to the atmosphere after Hg(0) was removed from the air (clearance). Pseudevernia furfuracea showed the highest Hg accumulation capacity and Evernia prunastri showed the lowest, but in these species the metal uptake kinetics was affected by temperature. Xanthoria parietina showed an intermediate metal accumulation capacity and a Hg accumulation rate independent of temperature (in the range 10-30 °C). The use of first-order kinetics equations for Hg uptake in X. parietina and available field data on Hg bioaccumulation in this species allowed reliable estimates of atmospheric Hg concentrations in the environment.
研究了三种附生地衣（假茶渍衣、欧洲树梅衣和条斑叶脐衣）在四种不同汞浓度（10、15、30 和 45μg/m³）和三种不同温度（10、20 和 30°C）下元素气态汞（Hg(0)）的吸收动力学，目的是评估地衣对 Hg(0)积累的效率及其在现场估算大气中这种金属浓度的潜力。结果表明，在我们的实验条件下，地衣根据暴露时间积累汞，并且在从空气中去除 Hg(0)后（清除），金属不会释放回大气中。假茶渍衣表现出最高的汞积累能力，欧洲树梅衣表现出最低的汞积累能力，但在这些物种中，金属吸收动力学受温度影响。条斑叶脐衣表现出中等的金属积累能力和与温度无关的汞积累率（在 10-30°C 范围内）。使用 X. parietina 中 Hg 吸收的一级动力学方程和该物种中 Hg 生物积累的可用现场数据，可以可靠估计环境中的大气 Hg 浓度。
