Concentrations of Cadmium, Copper, Lead and Zinc in Soils and Vegetable Organs from Periurban Agriculture Areas of Abidjan in Cote d’Ivoire

Abstract

Production quality in periurban agriculture is question mark regarding to soil potential contamination affecting yields. The level of contaminations of soils and vegetables by copper (Cu), zinc (Cu), cadmium (Cd) and lead (Pb) around Abidjan city were assessed. Survey was conducted in 2013 within cultivated areas of sweet potato and Hibiscus locally named “Dah” as encountered in three locations of Abidjan district (Port-Bouët, Yopougon and Bingerville) according to the intensities of industrial and commercial activities of which, Bingerville was the control site with lowest activities. Soil (0 – 20 cm) samples associated to that of plants (leaf, stem and root) were taken randomly for laboratory analysis. Toxic levels (> 8 mgkg-1) of Pb were significantly (p< .0001) determined in plant organs from Port-Bouët site indifferently to crops while, lower soil content of Pb (35.5 mgkg-1) than that of Yopougon (39.8 mgkg-1) was observed, however. Except the synergisms observed between leave concentration of Pb and soil contents of Cd, Cu and Zn, non of soil parameters were relevant for this while, the proximity of inland waters was suspected. The partitioning of Pb in plant organs pointed out phytoremediation potential of Hibiscus with lowest risk of toxicity (2.92 – 9.72 mgkg-1) in edible leave against an average of 8.08 mgPbkg-1 in the tuber of sweet potato. For strengthening consistence of knowledge, studies of Pb and Zn interaction as well as Pb translocation in tuber plants of tropical ecosystems were suggested.