Environmental impact of heavy metals (Fe, Ni, Cr, Co) in soils waters and plants of Triada in Euboea from ultrabasic rocks and nickeliferous mineralisation

Soil, water and vegetation samples were collected from the Triada area of C entral Euboea and analysed for heavy metals in order to evaluate their envi ronmental impact. The geology of the area studied includes ultrabasic rocks that are overlaid by Upper Cretaceous limestones whereas Fe-Ni mineralisat ion is intercalated between either the ultrabasic parent rocks or the karst ified Jurassic/Triassic carbonates and the transgessive Upper Cretaceous li mestones. All the samples were analysed for heavy metals by using atomic ab sorption spectroscopy. The heavy metal ranges (in mu g g(-1)) for soils sam ples are: Ni 480-4000, Cr 240-2720, Co 40-208, Fe 24,000-380,000, Mn 46-168 0, Pb 16-56, Zn 40-144, Cu 2-82. The values of soil samples of the Triada a rea are much higher than the values found for Ni, Cr, Co and Fe, in normal soils of the world. The heavy metal ranges (in mu g L-1) for water samples are: Ni 19-24, Cr 19-476, Co < 5, Fe < 100, Mn < 100, Mg 5.7-220.5, As 30-6 9, Cd < 2, Pd < 10, Zn 5-11, Cu 2-7. The water samples of the Triada area h ave Cr and Mg concentrations higher than the permittable values. The heavy metal ranges (in mu g g(-1)) for vegetation samples are: Ni 1-135, Cr 0-24, Co 1-21.5, Fe 20-680, Mn 10-206, Cd 0-10, Pb 0-14, Zn 14-70, Cu 0-10.5. Th e vegetation samples of the Triada area have so high values of Ni, Cr and C o that are considered toxic. The intercorrelated elements Fe, Ni, Cr, Co of the Triada soils, waters and vegetation reflect their association with the ultrabasic rocks and with the Fe-Ni mineralisation.