Environmental Toxicology , University of California , Santa Cruz , California 95064 , United States.
Environ Sci Technol. 2019 Jan 15;53(2):954-962. doi: 10.1021/acs.est.8b04191. Epub 2019 Jan 3.
The natural lead concentration of dandelion ( Taraxacum officinale) leaves is estimated to be 0.2 μg/g (dry weight), or 1-3 orders of magnitude below most contemporary measurements of that value for dandelions and other plants. This estimate is based on analyses of lead concentrations of dandelions grown in a trace metal clean laboratory, with environmental lead concentrations approximating natural levels. The protocols used in this study paralleled those in our previous study that estimated the natural blood lead level in humans (0.016 μg/dL), which is also 1-3 orders of magnitude below most contemporary measurements. Analyses of the isotopic ratios (Pb/Pb:Pb/Pb) of the lead in the plants grown in the laboratory and greenhouse and those collected in the field, as well as the isotopic ratios of the soils the plants were grown in in the laboratory, indicate that anthropogenic lead makes up a substantial amount of labile lead in today's environments. Consequently, this estimate of the natural lead level in dandelion leaves provides both a benchmark for comparison of lead concentrations in contemporary plants and yet another measure of persistent lead contamination in the biosphere.
蒲公英（Taraxacum officinale）叶片的天然铅浓度估计为 0.2μg/g（干重），比大多数现代蒲公英和其他植物的测量值低 1-3 个数量级。这一估计是基于在痕量金属清洁实验室中生长的蒲公英的铅浓度分析得出的，其环境铅浓度接近自然水平。本研究中使用的方案与我们之前研究人类天然血液铅水平（0.016μg/dL）的方案相似，后者也比大多数现代测量值低 1-3 个数量级。对实验室和温室中生长的植物以及野外采集的植物的铅同位素比值（Pb/Pb：Pb/Pb）以及植物在实验室中生长的土壤的同位素比值进行分析表明，人为铅构成了当今环境中大量可利用铅的来源。因此，这一蒲公英叶片天然铅水平的估计值不仅为当代植物中铅浓度的比较提供了基准，而且为生物圈中持续的铅污染提供了另一种衡量标准。
