Heavy metal pollution of some Danube Delta lacustrine sediments studied byneutron activation analysis

Using neutron activation analysis and radiometric measurements, the vertica l distribution of six possible pollutant elements (Zn, Cr, Co, As, Sb and B r), two trace elements of natural origin (Sc and Hf) and radioactive Cs-137 were determined in three lakes, Furtuna, Lung and Mesteru, located in an a ctive sedimentary zone of the Danube Delta. The accumulation rate of recent sediments was estimated from radiocesium profiles. Zn, As, Sb and Br were identified as possible pollutants. The vertical profiles of their concentra tions reflect recent historic inputs, showing a gradual increase until arou nd 1990, followed by a continuous decrease. (C) 2001 Elsevier Science Ltd. All rights reserved.