New Peat Bog Record of Atmospheric Lead Pollution in Switzerland: Pb Concentrations, Enrichment Factors, Isotopic Composition, and Organolead Species

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• 作者：W. Shotyk ; D. Weiss ; M. Heisterkamp ; A. K. Cheburkin ; P. G. Appleby ; and F. C. Adams
• 刊名：Environmental Science & Technology
• 出版年：2002
• 出版时间：September 15, 2002
• 年：2002
• 卷：36
• 期：18
• 页码：3893 - 3900
• 全文大小：224K
• 年卷期：v.36,no.18(September 15, 2002)
• ISSN：1520-5851

文摘

A peat core collected at Etang de la Gruère, an ombrotrophicbog in the Jura Mountains of Switzerland, was analyzedfor organolead species (DEL, TEL, DML, and TML) using GC-MIP AES, Pb isotopes using TIMS, and total Pb usingXRF and age-dated using ²¹⁰Pb. The earliest occurrenceof quantifiable alkyllead is found at a depth of 24 cm, whichis dated at AD 1946 ± 3; this finding is consistent withthe introduction of leaded gasoline in Switzerland in 1947.The maximum concentration of alkyllead (2.89 ng/g) isfound at 5 cm, which is dated at AD 1988 ± 2. This samesample yielded ²⁰⁶Pb/²⁰⁷Pb = 1.1254, which is the leastradiogenic value in the entire 2K core and comparable tothe isotopic composition of Pb in leaded gasoline. Thehighest concentrations of DML (906 ng/g) and DEL (1906 ng/g) also were found in this sample. Total alkyllead neveraccounts for more than 0.02% of total Pb in any given sample.The spatial and temporal variations in organolead speciesis matched by the changes in the isotopic compositionof Pb over the same interval. Despite this, the decline inanthropogenic Pb pre-dates the maximum in total alkylleadand minimum ²⁰⁶Pb/²⁰⁷ Pb, indicating that atmospheric Pbemissions had already begun their decline prior to theintroduction of unleaded gasoline. In fact, the decline inanthropogenic Pb was probably in response to the introductionof legislation, first in Germany and later in the EuropeanUnion, establishing a maximum allowable concentration ofPb in gasoline.