Disproportionately High Contributions of 60 Year Old Weapons-¹³⁷Cs Explain the Persistence of Radioactive Contamination in Bavarian Wild Boars

verfasst von

Felix Stäger, Dorian Zok, Anna Katharina Schiller, Bin Feng, Georg Steinhauser

Abstract

Radionuclides released from nuclear accidents or explosions pose long-term threats to ecosystem health. A prominent example is wild boar contamination in central Europe, which is notorious for its persistently high ¹³⁷Cs levels. However, without reliable source identification, the origin of this decades old problem has been uncertain. Here, we target radiocesium contamination in wild boars from Bavaria. Our samples (2019-2021) range from 370 to 15,000 Bq·kg^-1137Cs, thus exceeding the regulatory limits (600 Bq·kg^-1) by a factor of up to 25. Using an emerging nuclear forensic fingerprint, ¹³⁵Cs/¹³⁷Cs, we distinguished various radiocesium source legacies in their source composition. All samples exhibit signatures of mixing of Chornobyl and nuclear weapons fallout, with ¹³⁵Cs/¹³⁷Cs ratios ranging from 0.67 to 1.97. Although Chornobyl has been widely believed to be the prime source of ¹³⁷Cs in wild boars, we find that “old” ¹³⁷Cs from weapons fallout significantly contributes to the total level (10-68%) in those specimens that exceeded the regulatory limit. In some cases, weapons-¹³⁷Cs alone can lead to exceedances of the regulatory limit, especially in samples with a relatively low total ¹³⁷Cs level. Our findings demonstrate that the superposition of older and newer legacies of ¹³⁷Cs can vastly surpass the impact of any singular yet dominant source and thus highlight the critical role of historical releases of ¹³⁷Cs in current environmental pollution challenges.

Organisationseinheit(en)

Institut für Radioökologie und Strahlenschutz

Externe Organisation(en)

Technische Universität Wien (TUW)

Typ

Artikel

Journal

Environmental Science and Technology

Band

57

Seiten

13601–13611

Anzahl der Seiten

11

ISSN

0013-936X

Publikationsdatum

12.09.2023

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Chemie (insg.), Umweltchemie

Ziele für nachhaltige Entwicklung

SDG 12 – Verantwortungsvoller Konsum und Produktion

Elektronische Version(en)

https://doi.org/10.1021/acs.est.3c03565 (Zugang: Offen)