Quantitative evaluation of multi-walled carbon nanotube uptake in wheat and rapeseed.
Environmental contamination with carbon nanotubes would lead to plant exposure and particularly exposure of agricultural crops. The only quantitative exposure data available to date which can be used for risk assessment comes from computer modeling. The aim of this study was to provide quantitative data relative to multi-walled carbon nanotube (MWCNT) uptake and distribution in agricultural crops, and to correlate accumulation data with impact on plant development and physiology. Roots of wheat and rapeseed were exposed in hydroponics to uniformly (14)C-radiolabeled MWCNTs. Radioimaging, transmission electron microscopy and raman spectroscopy were used to identify CNT distribution. Radioactivity counting made it possible absolute quantification of CNT accumulation in plant leaves. Impact of CNTs on seed germination, root elongation, plant biomass, evapotranspiration, chlorophyll, thiobarbituric acid reactive species and H(2)O(2) contents was evaluated. We demonstrate that less than 0.005‰ of the applied MWCNT dose is taken up by plant roots and translocated to the leaves. This accumulation does not impact plant development and physiology. In addition, it does not induce any modifications in photosynthetic activity nor cause oxidative stress in plant leaves. Our results suggest that if environmental contamination occurs and MWCNTs are in the same physico-chemical state than the ones used in the present article, MWCNT transfer to the food chain via food crops would be very low.
UMR3299 CEA-CNRS, Service Interdisciplinaire des Systèmes Moléculaires et Matériaux, Laboratoire Structure et Dynamique par Résonance Magnétique (LSDRM), CEA Saclay, 91191 Gif sur Yvette, France. Camille.larue@cea.fr
Camille
C
Larue
Mathieu
M
Pinault
Bertrand
B
Czarny
Dominique
D
Georgin
Danielle
D
Jaillard
Nedjma
N
Bendiab
Martine
M
Mayne-L'Hermite
Frédéric
F
Taran
Vincent
V
Dive
Marie
M
Carrière
D029741:Brassica rapa / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D004785:Environmental Pollutants / Q000378:metabolism*; D018527:Hydroponics; D037742:Nanotubes, Carbon / Q000032:analysis* / Q000633:toxicity; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D014908:Triticum / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*
D004785:Environmental Pollutants; D037742:Nanotubes, Carbon