| Title | Geochronology of Hg pollution in italian sub-alpine lakes |
| Abstract | The deep, large subalpine lakes (DSL), located south of the Alps between Italy and Switzerland, are regionally important economic and environmental resources. DSL share several common morphological features (e.g., narrow and elongated shapes, steep sides, considerable depths, and most often north-south orientation), although the lithological and petrographical composition of their watersheds differs markedly because of the geological complexity of the Alpine region. Most of the DSL experienced eutrophication during the 20th century and their present trophic status varies from oligotrophy (e.g., Lake Maggiore, thanks to recovery measures) to eutrophy (e.g., Lake Lugano). To assess how regional vs. local factors influence the Hg cycle in the DSL, several sediment cores covering the last 100 to 700 years (depending on core length and sedimentation rates) were collected at suitable locations of DSL. The deepest sections of each core were usually free from human influences (pre-1850) and show that background Hg levels (0.05-0.1 mg kg-1) are similar across the DSL despite differences in watersheds composition. Mercury content in the top-layers of the cores remains above background levels in all DSL and moderate to strong anthropogenic impact is observed not only in Lake Maggiore (for which a well-documented history of Hg pollution exists), but also in lakes Orta and Como. Analysis of the complete Hg profiles is being undertaken and will elucidate how Hg deposition in DSL responds to changes in trophic status and regional climate patterns. |
| Source | VI World Congress of the Society of Environmental Toxicology and Chemistry "Securing a sustainable future: Integrating science, policy and people", Berlino, Germania, 20-24 maggio 2012 |
| Keywords | SedimentsMercuryItalian lakesContaminationReference levels |
| Year | 2012 |
| Type | Presentazione |
| Authors | Ponti, Benedetta; Guilizzoni, Piero; Lami, Andrea; Gerli, Stefano; Vezzoli, Luigina; Bettinetti, Roberta; Salerno, Franco; Salmaso, Nico; Veronesi, Mauro; Simona, Marco; Marchese, Gabriele; Pola, Annalisa; Vignati, Davide |
| Text | 222898 2012 Sediments Mercury Italian lakes Contamination Reference levels Geochronology of Hg pollution in italian sub alpine lakes Ponti, Benedetta; Guilizzoni, Piero; Lami, Andrea; Gerli, Stefano; Vezzoli, Luigina; Bettinetti, Roberta; Salerno, Franco; Salmaso, Nico; Veronesi, Mauro; Simona, Marco; Marchese, Gabriele; Pola, Annalisa; Vignati, Davide Universita dell Insubria Como; CNR ISE, Pallanza Verbania; CNR ISE, Pallanza Verbania; CNR ISE, Pallanza Verbania; Universita dell Insubria Como; Universita dell Insubria Como; CNR IRSA, Brugherio; IASMA, S. Michele all Adige; SUPSI, Istituto Scienze della Terra, C.P. 72, CH 6952 Canobbio Lugano; SUPSI, Istituto Scienze della Terra, C.P. 72, CH 6952 Canobbio Lugano; CNR IRSA, Brugherio; CNR IRSA, Brugherio; CNR IRSA, Brugherio The deep, large subalpine lakes DSL , located south of the Alps between Italy and Switzerland, are regionally important economic and environmental resources. DSL share several common morphological features e.g., narrow and elongated shapes, steep sides, considerable depths, and most often north south orientation , although the lithological and petrographical composition of their watersheds differs markedly because of the geological complexity of the Alpine region. Most of the DSL experienced eutrophication during the 20th century and their present trophic status varies from oligotrophy e.g., Lake Maggiore, thanks to recovery measures to eutrophy e.g., Lake Lugano . To assess how regional vs. local factors influence the Hg cycle in the DSL, several sediment cores covering the last 100 to 700 years depending on core length and sedimentation rates were collected at suitable locations of DSL. The deepest sections of each core were usually free from human influences pre 1850 and show that background Hg levels 0.05 0.1 mg kg 1 are similar across the DSL despite differences in watersheds composition. Mercury content in the top layers of the cores remains above background levels in all DSL and moderate to strong anthropogenic impact is observed not only in Lake Maggiore for which a well documented history of Hg pollution exists , but also in lakes Orta and Como. Analysis of the complete Hg profiles is being undertaken and will elucidate how Hg deposition in DSL responds to changes in trophic status and regional climate patterns. ID_PUMA /cnr.ise/2012 A3 002. Poster VI World Congress of the Society of Environmental Toxicology and Chemistry Securing a sustainable future Integrating science, policy and people Berlino, Germania 20 24 maggio 2012 Internazionale Geochronology of Hg pollution in italian sub alpine lakes Geochronology_of_Hg_Pollution_in_Italian_sub_alpine_Lakes.pdf Presentazione GERLI STEFANO piero.guilizzoni GUILIZZONI PIERO franco.salerno SALERNO FRANCO davideanselmoluigi.vignati VIGNATI DAVIDE ANSELMO LUIGI andrea.lami LAMI ANDREA TA.P02.014.002 Impatto dei cambiamenti globali sugli ecosistemi acquatici |
