Wildfires on Cr-rich Ferralsols can cause freshwater Cr(VI) pollution: A pilot study in New Caledonia
2023
Thery, Gaël | Juillot, Farid | Meyer, Michaël | Quiniou, Thomas | David, Magali | Jourand, Philippe | Ducousso, Marc | Fritsch, Emmanuel | Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC) ; Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) | Géosciences Paris Saclay (GEOPS) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) | Institut de sciences exactes et appliquées (ISEA) ; Université de la Nouvelle-Calédonie (UNC) | Laboratoire des symbioses tropicales et méditerranéennes (UMR LSTM) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM) | Département Systèmes Biologiques (Cirad-BIOS) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | This work was supported by funding from the Centre National de Recherche Technologique sur le nickel et son environnement under the CHRONICK project (grant CNRT CSF 7PS2017). Soil samples collection was done under the ADASPIR project funded by the Agence Nationale de la Recherche (grant ANR-12-ADAP-0017). The authors are indebted to Leocadie Jamet, Anne Desnues, Stephanie Berne and Felise Liufau for ICP-OES measurements at the Laboratoire des Moyens Analytiques (LAMA-IMAGO) of Institut de Recherche pour le Developpement (IRD) Noumea (New Caledonia). Koniambo Nickel Society (KNS) is acknowledged for providing the results of in-situ turbidity and suspended particulate matter measurements performed at the outlet of the Coco catchment. | ANR-12-ADAP-0017,ADASPIR,Mécanismes symbiotiques d'adaptations d'Acacia spirorbis aux stress abiotiques et aux perturbations environnementales en Nouvelle Calédonie(2012)
International audience
اظهر المزيد [+] اقل [-]إنجليزي. Highlights: • Heating of Cr-rich Ferralsols can result in a significant increase of mobile chromium. • About 80% of mobile chromium after Cr-rich Ferralsols heating occurs as Cr(VI). • The Fe-oxides/silicates ratio seems to control Cr(VI) mobility upon soil heating. • Cr(VI) concentration in ultramafic freshwaters can exceed WHO GDWQ after wildfires. • Risk of wildfires-induced freshwater Cr(VI) pollution should be assessed worldwide.Abstract: In the context of global warming, environmental forcing of wildfires on continental ecosystems is on a growing trend. Among other environmental impacts, wildfires can enhance trace metals concentration in freshwater systems. In this regard, chromium is of particular environmental and health concern because the temperature-induced oxidation of the less mobile and toxic Cr(III) form to the most mobile and toxic Cr(VI) one might represent a risk of freshwater pollution. The aim of the present study was to make a first assessment of this risk in New Caledonia by quantifying the influence of soil heating on Cr(VI) mobility in Cr-rich Ferralsols that cover about 1/3 of this French overseas territory. The results obtained indicated an enhanced Cr(VI) mobility upon soil heating from 200 °C, with a marked turnaround from 400 °C. Based on these results, a solid/solution mass balance approach allowed to confirm the risk of freshwater Cr(VI) pollution as a function of suspended particulate matter (SPM) concentration issued from burned Cr-rich Ferralsols. In addition, the results obtained revealed an apparent control of the Fe-oxides/silicates ratio on Cr(VI) mobility upon soil heating. Since this ratio decreases from the top to the bottom of ultramafic catchments, this latter result suggests that the risk of freshwater Cr(VI) pollution could depend on the actual location of the wildfires at the top or slope/base of these catchments. Since freshwaters represent the major water resource for the inhabitants of New Caledonia, these results point to the need for a larger evaluation of the risk of wildfires-induced freshwater Cr(VI) pollution at other catchments composed of Cr-bearing soils like Cambisols and Vertisols. At the larger scale, they also point to the need to foster studies aimed at better evaluating the risk of wildfires-induced freshwater Cr(VI) pollution at Cr-bearing pedological settings worldwide.
اظهر المزيد [+] اقل [-]الكلمات المفتاحية الخاصة بالمكنز الزراعي (أجروفوك)
المعلومات البيبليوغرافية
تم تزويد هذا السجل من قبل Institut national de la recherche agronomique