Περίληψη:
Lead was determined in surface sediments and cores of a typical, polluted, almost enclosed Mediterranean embayment, the Gulf of Elefsis, near Athens. Total lead concentrations of 500-600 μg g-1 were found in the surface sediments of the northeast section of the gulf, near major industries. However, a few kilometers from the source the concentrations decrease to ∼ 40m μg g-1; the background pre-industrial levels are ∼ 10 μg g-1 (in the < 61 μm fraction). Sequential extractions, consideration of the Pb/Al and Pb/Zn ratios, etc., indicate that the upper 5-15 cm of the sediment column are greatly enriched with lead of anthropogenic origin, which is mainly associated with fine particles. Redox reactions play an important role in the distribution and chemistry of lead, most of which (∼ 40%) is associated with organic matter and sulphides (extracted by EDTA); another ∼ 30% is associated with iron and manganese coatings and carbonates, with only a small but significant 3-4% of the total in a readily exchangeable form. The latter, under given conditions, may influence the lead concentrations in the overlying waters. © 1986.
Λέξεις-κλειδιά:
LEAD COMPOUNDS - Environmental Impact; SEAWATER - Analysis, ELEFSIS GULF, GREECE, COASTAL ZONES, lead, geographic distribution; greece; nonhuman; priority journal; sea pollution; sediment; theoretical study
