Background Levels of Heavy Metals and PAHs in Permafrost Sediments of the Lena Delta, Siberia

• Main Author: Antsibor, Julia B.
• Format: Thesis
• Language: English
• Published: 2009
• Subjects: Arctic; lena delta; lena river; permafrost; Siberia
• Online Access: https://oceanrep.geomar.de/id/eprint/28393/; https://oceanrep.geomar.de/id/eprint/28393/1/2009_Antsibor-Julia_MSc-Thesis_eng.pdf

The studies of pollutants such as heavy metals and hydrocarbons and their influence on natural ecosystems draw attention in recent decades due to intensive industry development. The northern areas are in particular sensitive to influence of contaminants since they have low recovery potential. The Lena River Delta belongs to the Arctic regions which are quite far from industrial centers and therefore least of all subjected to human impact. However this area located in the permafrost area is characterized by specific environment that makes this ecosystem more vulnerable to any human activity. The present study represents the first attempt to determine background levels of heavy metals and polycyclic aromatic hydrocarbons (PAHs) for the site of interest. Here the results of physical and chemical investigations of the core sample are proposed. The core with length 540 cm was formed during Quaternary period and presented by alternation of silt sand with the rest of plants. It was recovered while joint Russian-German expedition in 2007. Study of selected samples was based on the Laboratory of the Institute of Soils science, Hamburg University (Hamburg, Germany). As part of the laboratory study we determined grading of soil, water content, soil acidity, organic matter content, total heavy metals (Zn, Cd, Pb, Ni) and As content and sum composition of PAHs as well. On basis of the obtained results on the core it was found out that heavy metals were accumulated in the horizons composed of silt fractions whereas its minimal content was detected in horizons of fine-grained sand. Overall the heavy metals concentrations were higher in the bottom of the profile in comparison with overlying layers. The behavior of As within the profile was in the opposite way. The maximum was observed on 12-15 cm depth then within the all profile As content was not varied a lot. The correlation analysis showed the significant positive relation between the following metals: Zn and Ni, Zn and Cd, Cd and Pb. Comparative analysis of findings with ...