A 300 year history of lead contamination in northern French Alps reconstructed from distant lake sediment records

• Published in: J. Environ. Monit.
• Main Authors: Arnaud, Fabien, Revel-Rolland, Marie, Bosch, Delphine, Winiarski, T., Desmet, M., Tribovillard, Nicolas, Givelet, N.
• Other Authors: Processus et bilan des domaines sédimentaires (PBDS), Université de Lille, Sciences et Technologies-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géodynamique des Chaines Alpines (LGCA), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Tectonophysique (Tectonophysique), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Environnement (LSE-ENTPE), École Nationale des Travaux Publics de l'État (ENTPE)-Université de Lyon-Ministère de l'Ecologie, du Développement Durable, des Transports et du Logement
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2004
• Subjects: [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; Mont Blanc; ice core
• Online Access: https://hal.science/hal-03890731; https://doi.org/10.1039/B314947A

International audience Lead concentrations and isotopic ratios were measured along two well-dated sediment cores from two distant lakes: Anterne (2100 m a.s.l.) and Le Bourget (270 m a.s.l.), submitted to low and high direct human impact and covering the last 250 and 600 years, respectively. The measurement of lead in old sediment samples (>3000 BP) permits, in using mixing-models, the determination of lead concentration, flux and isotopic composition of purely anthropogenic origin. We thus show that since ca. 1800 AD the regional increase in lead contamination was mostly driven by coal consumption (206Pb/207Pb ∼ 1.17–1.19; 206Pb/204Pb ∼ 18.3–18.6), which peaks around 1915 AD. The increasing usage of leaded gasoline, introduced in the 1920s, was recorded in both lakes by increasing Pb concentrations and decreasing Pb isotope ratios. A peak around 1970 (206Pb/207Pb ∼ 1.13–1.16; 206Pb/204Pb ∼ 17.6–18.0) corresponds to the worldwide recorded leaded gasoline maximum of consumption. The 1973 oil crisis is characterised by a drastic drop of lead fluxes in both lakes (from ∼35 to <20 mg cm−2 yr−1). In the late 1980s, environmental policies made the Lake Anterne flux drop to pre-1900 values (<10 mg cm−2 yr−1) while Lake Le Bourget is always submitted to an important flux (∼25 mg cm−2 yr−1). The good match of our distant records, together and with a previously established series in an ice core from Mont Blanc,1 provides confidence in the use of sediments as archives of lead contamination. The integration of the Mont Blanc ice core results from Rosman et al.1 with our data highlights, from 1990 onward, a decoupling in lead sources between the high elevation sites (Lake Anterne and Mont Blanc ice core), submitted to a mixture of long-distance and regional contamination and the low elevation site (Lake Le Bourget), where regional contamination is predominant.