Shotyk W, Weiss D, Appleby PG, Cheburkin AK, Gloor RFM, Kramers JD, Reese S
W. Shotyk and D. Weiss are at the Geological Institute, University of Berne, Baltzerstrasse 1, CH-3012 Berne, Switzerland. P. G. Appleby is in the Environmental Radiometric Research Centre, Department of Mathematical Sciences, Universit.
Science. 1998 Sep 11;281(5383):1635-40. doi: 10.1126/science.281.5383.1635.
A continuous record of atmospheric lead since 12,370 carbon-14 years before the present (14C yr BP) is preserved in a Swiss peat bog. Enhanced fluxes caused by climate changes reached their maxima 10, 590 (14)C yr BP (Younger Dryas) and 8230 (14)C yr BP. Soil erosion caused by forest clearing and agricultural tillage increased lead deposition after 5320 (14)C yr BP. Increasing lead/scandium and decreasing lead-206/lead-207 beginning 3000 (14)C yr BP indicate the beginning of lead pollution from mining and smelting, and anthropogenic sources have dominated lead emissions ever since. The greatest lead flux (15.7 milligrams per square meter per year in A.D. 1979) was 1570 times the natural, background value (0.01 milligram per square meter per year from 8030 to 5320 (14)C yr BP).
瑞士泥炭沼泽保存了自距今12370碳-14年(14C yr BP)以来大气铅含量的连续记录。气候变化导致的通量增强在距今10590(14C yr BP,新仙女木期)和8230(14C yr BP)时达到最大值。森林砍伐和农业耕作导致的土壤侵蚀在距今5320(14C yr BP)之后增加了铅的沉积。从距今3000(14C yr BP)开始,铅/钪比值增加以及铅-206/铅-207比值降低,表明采矿和冶炼造成的铅污染开始出现,自那时起人为源一直主导着铅排放。最大铅通量(公元1979年为每年每平方米15.7毫克)是自然背景值(距今8030至5320(14C yr BP)为每年每平方米0.01毫克)的1570倍。