PARENT SESSION

PM07 Pollutant Chemistry Transport, Cycling and Fate
Exhibit Hall
8:00 AM - Monday

(PM069) Polyciclic Aromatic Hydrocarbons (PAHs) in sediments from three Andean Lakes in Central South Chile.

Barra, Ricardo¹, Popp, Peter², Quiroz, Roberto¹, Treutler, Hanns², Urrutia, Roberto¹, Bauer, Coretta², Araneda, Alberto¹, ¹ EULA-Chile Environmental Sciences Center, University of Concepción, Concepción, Chile² UFZ-Center for Environmental Reserch; Department of Analytical Chemistry, Leipzig, Germany

ABSTRACT- PAHs are ubiquitous in the environment, however anthropogenic activities could contribute in a significant way to the total burden of PAHs in mountain remote areas. In fact a significant increase of anthropogenic deposition of PAHs in remote lakes in Europe have been described, however no evidence of such increase have been provided for the southern hemisphere, where industrialization process are not such intensive. In this work, we document the analysis of PAHs deposition trough the sedimentary records obtained in three Andean lakes located in south Central Chile Andes Mountains. There is no record of PAHs pollution in remote areas in Chile, even PAHs have been widely detected in air samples from urban environments. Sediments cores were taken in the deepest section of each lake ranging from 100-140 m depth. Sediments were carefully extruded in 1 cm layers for PAHs analysis and dating. Extraction of the samples were performed using accelerated solvent extraction. The analysis were performed using HPLC with fluorescence detection. 15 EPA prioritary PAHs were analyzed. Detection limits ranged from 0.1-0.5 ng g^-1 for each individual PAH. Dating of sediments was possible for the Laja and Galletue Lakes, and ²¹⁰Pb and ¹³⁷Cs were used for reconstructing deposition rates and estimating fluxes. The superficial composition of PAHs in each lake is rather similar with a characteristic dominance by perylene, but levels are higher in Galletue lakes being 9.53 ng g^-1 OC compared to 4.98 ng g^-1 OC in the Laja lake. Total deposition fluxes averaged 71-972 g m² year in the Laja Lake. All the experimental evidence supports a natural source,however it is no clear whether alloctonous or autoctonous sources explains the observed patterns. Research supported by CONICYT BMBF 2000-111 and FONDECYT 1010640.

Key words: Chile, lake, PAHs, Sediments