Metallic contaminant profiles in sediment cores from Lake Valencia, Venezuela

Abstract

Total extractable concentrations of AI, Fe, Mn, Pb, Cu, Zn, Hg and organic carbon (Corg) were determined along four sediment cores from Lake Valencia. In one selected core, the percentage labile fractions were determined in order to establish anthropic enrichment factors, the depth reached by the contaminants and their mobilities. The distribution patterns of concentration versus depth reflect the original concentrations of the settling sediments. Only Mn seems to show diagenetic cycling. No enrichment of Fe and Mn occurs in the upper part of the cores, in spite of good water circulation and aeration of bottom lake waters during five months of the year. This immobility can be attributed to the high pH of water (7.6 - 8.9). Pb, Zn, Cu and Hg are enriched in the upper part of the cores, probably reflecting the input of contaminants. These elements show enrichment factors of up to 3.0. Background concentrations of the studied metals are reached below a depth of 30 cm.

Heavy Metals Analysis and Sediment Quality Values in Urban Lakes

“…Samples were air dried in the laboratory at room temperature, ground in fine mixture using mortar and pestle before sieved under 2 mm mesh. The samples were then stored in a polythene container ready for digestion and analysis [13][14][15][16] .…”

Lead Contamination Adjacent to Roadways in Trujillo, Venezuela

“…Examples of existing research include blood level studies conducted during the 1980s and early 1990s (Granadillo and Romero 1987;Granadillo et al 1990;Burguera et al 1991;Granadillo 1993;Granadillo et al 1994), and lead's effects on renal function Romero 1994). Other studies include research on heavy metals in Venezuelan rivers and lakes (Mogollon et al 1990;Bifano and Mogollon 1995), lead concentrations in Venezuelan cigarettes (Alvarado and Cristiano 1993), and lead accumulation in ornamental plants (Medina and Urdaneta 1993).…”