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1.
Lavado RS 《Journal of environmental management》2006,80(2):116-119
Soils of the Pampas show no signs of contamination with potentially toxic elements (PTEs), except in the areas that surround cities. The concentration of PTE in crops grown in this region is in most cases unknown. Our objective was to determine the PTE concentration in main field crops and pastures grown in 'a priori' non-contaminated areas and in potentially contaminated areas around cities. Forty-eight plots from farms located far from cities or roads and 36 plots from farms located very close to cities or to high traffic roads were sampled. The area ranged from 33 degrees 40' S to 36 degrees 0' S and from 57 degrees 35' W to 61 degrees 22' W. Maize, soybean, wheat, grazed grassland and pastures, and their top soils were sampled. All samples were acid digested. Cadmium, zinc, chromium, copper, nickel and lead were determined using ICPES. Standard t-tests were performed. All soils were within the known normal values of soil PTE concentrations, with the exception of a few cases around cities. PTE accumulation on grains and aerial biomass is considered almost negligible in crops grown in both studied areas, with the exception of a few elements in soybean. PTE concentrations in crops and pastures are in keeping with the low content of trace metals found in soils of the Pampas. 相似文献
2.
The concentrations of heavy metals (mg/g) Pb, Ni, Cu, Cr, Fe, Co, Cd, and Hg in the tissues of young and adult toads exposed
to petroleum-polluted environment were determined in order to assess the impact of petroleum-processing activities in Ekpan.
The data showed that the levels of these Metals ranged between 0.15–1.18 and 0.10–0.48 in young and adult toads respectively.
The heavy metals concentrations reported for the young toads have an abundance trend in the order of Pb > Fe > Ni > Cr > Cu > Co > Cd > Hg,
while those of the adult toads are in the order of Pb > Fe > Cr > Ni > Cu > Cd > Hg > Co. The control analysis was carried
out in a non-oil polluted area (Obiaruku) and the values served as base line values for the study. 相似文献