Temporal trends of polycyclic aromatic hydrocarbons (PAHs) in a dated sediment core of a high atitude mountain lake: Chungara Lake-Northern Chile (18° S)

In this study levels, fuxes and temporal trend of PAHs are reported in a sediment core from Chungará Lake (18° S) in Northern Chile. The sediments were obtained by Kayac corer and freeze dried. PAHs were extracted in SOXHLET system and measured by HPLC with diode array detector and fuorescence detection. Sedimentary record chronology was determined using210Pb isotopes and organic carbon (%) was also measured in sediments. Concentrations (ng g-1 d.w.) of PAHs were low ranging from ∼1 to 50. PAHs fngerprint was dominated by 3-ring (21%) and 4-ring. Organic carbon (%) ranged from ∼17 to 24 (21±3) and no statistical signifcant correlation (p<0.05) was detected between OC (%) and PAHs along the sediment core. PAHs fuxes (μg m-2yr-1) fuctuated from ∼0.3 (cm 1) to 35 (cm 5) in 1978. LPAHs/HPAHs ratios (0.04 to 3) indicate petrogenic and pyrolytic origin of PAHs. This results contributes with new information of PAHs deposition at high altitudinal lake in Southern Hemisphere.