Lead bioaccumulation in Opuntia ficus-indica following foliar or root exposure to lead-bearing apatite.
The contamination of edible leafy vegetables by atmospheric heavy metal-bearing particles is a major issue in environmental toxicology. In this study, the uptake of lead by cladodes of Opuntia ficus-indica (Ofi), traditionally used in Mexican cuisine and in livestock fodder, is investigated after a 4-months exposure of either cladodes or roots to synthetic Pb-fluorapatite particles. Atomic Absorption Spectroscopy (AAS) for the quantitative analysis of Pb levels, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy (SEM-EDX) for the examination of the cladode surface and fate of particles, and Micro-X-ray fluorescence (μXRF) measurements for elemental mapping of Pb in cladodes, were used. The results evidence that foliar contamination may be a major pathway for the transfer of Pb within Ofi cladodes. The stomata, areoles, and cuticle of cladode surface, play an obvious role in the retention and the incorporation of lead-bearing apatite, thus revealing the hazard of eating contaminated cladodes. The possibility of using series of successive cladodes for biomonitoring the atmospheric pollution in arid and semi-arid regions is also rapidly discussed.
University of Toulouse (Paul Sabatier), Laboratoire Geosciences Environment Toulouse (UMR CNRS-UPS 5563 IRD 234), 14 Av. Edouard Belin, 31400 Toulouse, France; Lebanese University, Plateforme de Recherche et d'Analyses en Sciences de l'Environnement, Ecole Doctorale des Sciences et Technologies, Hadath, Lebanon. Electronic address: elhayek@unm.edu.
Eliane
E
El Hayek
Lebanese University, Plateforme de Recherche et d'Analyses en Sciences de l'Environnement, Ecole Doctorale des Sciences et Technologies, Hadath, Lebanon.
Antoine
A
El Samrani
University of Toulouse (Paul Sabatier), Laboratoire Geosciences Environment Toulouse (UMR CNRS-UPS 5563 IRD 234), 14 Av. Edouard Belin, 31400 Toulouse, France.
Bruno
B
Lartiges
Lebanese University, Plateforme de Recherche et d'Analyses en Sciences de l'Environnement, Ecole Doctorale des Sciences et Technologies, Hadath, Lebanon.
Veronique
V
Kazpard
University of Toulouse (Paul Sabatier), Laboratoire Geosciences Environment Toulouse (UMR CNRS-UPS 5563 IRD 234), 14 Av. Edouard Belin, 31400 Toulouse, France.
Thierry
T
Aigouy
D001031:Apatites / Q000633:toxicity*; D004784:Environmental Monitoring; D007854:Lead / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D029747:Opuntia / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013052:Spectrometry, X-Ray Emission; D013054:Spectrophotometry, Atomic
D001031:Apatites; D010936:Plant Extracts; D012989:Soil Pollutants; D007854:Lead
Foliar or root exposure; Opuntia ficus-Indica; Pb uptake; SEM-EDX; μXRF