Université de Toulouse; INP, UPS, EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement), ENSAT, Avenue de l'Agrobiopole, 31326 Castanet Tolosan, France.
Sci Total Environ. 2012 Jun 15;427-428:253-62. doi: 10.1016/j.scitotenv.2012.03.051. Epub 2012 May 3.
Fine and ultrafine metallic particulate matters (PMs) are emitted from metallurgic activities in peri-urban zones into the atmosphere and can be deposited in terrestrial ecosystems. The foliar transfer of metals and metalloids and their fate in plant leaves remain unclear, although this way of penetration may be a major contributor to the transfer of metals into plants. This study focused on the foliar uptake of various metals and metalloids from enriched PM (Cu, Zn, Cd, Sn, Sb, As, and especially lead (Pb)) resulting from the emissions of a battery-recycling factory. Metal and metalloid foliar uptake by various vegetable species, exhibiting different morphologies, use (food or fodder) and life-cycle (lettuce, parsley and rye-grass) were studied. The mechanisms involved in foliar metal transfer from atmospheric particulate matter fallout, using lead (Pb) as a model element was also investigated. Several complementary techniques (micro-X-ray fluorescence, scanning electron microscopy coupled with energy dispersive X-ray microanalysis and time-of-flight secondary ion mass spectrometry) were used to investigate the localization and the speciation of lead in their edible parts, i.e. leaves. The results showed lead-enriched PM on the surface of plant leaves. Biogeochemical transformations occurred on the leaf surfaces with the formation of lead secondary species (PbCO(3) and organic Pb). Some compounds were internalized in their primary form (PbSO(4)) underneath an organic layer. Internalization through the cuticle or penetration through stomata openings are proposed as two major mechanisms involved in foliar uptake of particulate matter.
细颗粒和超细金属颗粒（PM）是在城市周边冶金活动中排放到大气中的，可以在陆地生态系统中沉积。尽管这种渗透方式可能是金属向植物转移的主要途径，但金属和类金属在植物叶片中的叶转移及其归宿仍然不清楚。本研究集中于从电池回收厂排放的富含 PM（Cu、Zn、Cd、Sn、Sb、As，尤其是铅（Pb））中各种金属和类金属的叶吸收。研究了不同形态、用途（食物或饲料）和生命周期（生菜、欧芹和黑麦草）的各种蔬菜物种对金属和类金属的叶吸收。还研究了利用铅（Pb）作为模型元素从大气颗粒物沉降中进行叶转移的机制。使用了几种互补技术（微 X 射线荧光、扫描电子显微镜结合能量色散 X 射线微分析和飞行时间二次离子质谱）来研究其可食用部分（即叶片）中铅的定位和形态。结果表明，植物叶片表面存在富含铅的 PM。在叶片表面发生了生物地球化学转化，形成了铅的次生物种（PbCO(3)和有机铅）。一些化合物以原始形式（PbSO(4)）被内化在有机层下。通过角质层内化或通过气孔开口渗透被提出为两种主要的颗粒物质叶吸收机制。
