Doelsch Emmanuel, Van de Kerchove Virginie, Saint Macary Hervé.
2004. Heavy metal concentrations in soils of La Reunion island (Indian Ocean) : anthropogenic contamination or natural pedo-geochemical background?.
In : 4th International Symposium Environmental Geochemistry in Tropcial Countries, Buzios, Brazil, 25-29 October 2004
Résumé : The rapid population growth of La Reunion island (Indian Ocean) is correlated with an increase of agricultural, industrial and urban activities. It results in a strong increase of production of various wastes. Recycling of wastes in Agriculture is an interesting solution in an insular context since it allows (i) the valorization of various organic wastes; (ii) the use of products having a fertilizing value thus allowing economies in mineral fertilizer; (iii) the improvement of the physical properties of soils and (iii) the development of soil microflora and fauna activities. Nevertheless, it is fundamental to control the environmental impact of these practices which can result in contamination of natural resources (soil, water) by inorganic or organic pollutants. Among these pollutants, heavy metals are carefully examined since they can be toxic for humans, animals and plants. However, no study on heavy metal concentration or distribution in soils have been conducted in La Reunion island. The objectives of this investigation are (i) to determine the concentration and the distribution of heavy metal in La Reunion island soils and (ii) to identify the origin of heavy metals present in Reunion island soils. 39 sampling sites were selected to cover the distribution of soils of the island. Both cultivated and uncultivated soils were sampled from 1 to 3 horizons, and 84 soils samples were analyzed. The soils of La Reunion island are acid (median of pHwater=5.7) and heavy metals rich (median value: 0.15 ppm for Cd, 0.16 ppm Hg, 52.9 ppm for Cu, 92.14 ppm for Ni, 146.1 for Zn and 165.9 ppm for Cr). To identify the sources of heavy metals occurring in soils we used comparison of heavy metals content between cultivated and uncultivated soils, the heavy metals distribution in soil profiles and the relationship between heavy metals content in soils and origin of volcanic parent material. Cd and Pb evolution in soils profile indicate an impact of human activities. High Hg concentrations in soils can be explained by volcanic activities of the island. For Cr, Cu, Ni and Zn we demonstrate that high concentrations in soils are mainly determined by the natural pedo-geochemical background. (Texte intégral)
Mots-clés Agrovoc : élément métallique, composition globale, sol, propriété physicochimique du sol
Mots-clés géographiques Agrovoc : La Réunion, France
Classification Agris : P33 - Chimie et physique du sol
Auteurs et affiliations
-
Doelsch Emmanuel, CIRAD-CA-GEC (REU)
ORCID: 0000-0002-7478-4296
- Van de Kerchove Virginie, Chambre d'agriculture de la Réunion (REU)
- Saint Macary Hervé, CIRAD-CA-DIR (REU)
Autres liens de la publication
Source : Cirad - Agritrop (https://agritrop.cirad.fr/528241/)
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