Lead bioaccumulation in Opuntia ficus-indica following foliar or root exposure to lead-bearing apatite

Eliane El Hayek (1) , Antoine El Samrani (2) , Bruno Lartiges (1) , Véronique Kazpard (2) , Thierry Aigouy (1)

1 GET - Géosciences Environnement Toulouse
2 LU / ULB - الجامعة اللبنانية [بيروت] = Lebanese University [Beirut] = Université libanaise [Beyrouth]

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.

Mots clés: foliar or root exposure; Pb uptake; SEM-EDX; Opuntia ficus-indica; μXRF

Domaines: Ingénierie de l'environnement

Eliane El Hayek, Antoine El Samrani, Bruno Lartiges, Véronique Kazpard, Thierry Aigouy. Lead bioaccumulation in Opuntia ficus-indica following foliar or root exposure to lead-bearing apatite. Environmental Pollution, 2017, 220, pp.779-787. ⟨10.1016/j.envpol.2016.10.046⟩. ⟨hal-02182876⟩