Long-term decline of Chernobyl-derived 137Cs in mosses and lichens from the Eastern Black Sea region of Türkiye
Journal of Environmental Radioactivity, cilt.298, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 298
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.jenvrad.2026.108104
- Dergi Adı: Journal of Environmental Radioactivity
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Artic & Antarctic Regions, BIOSIS, Chemical Abstracts Core, Compendex, EMBASE, Environment Index, Geobase, INSPEC, MEDLINE, Zoological Record, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Recep Tayyip Erdoğan Üniversitesi Adresli: Evet
Özet
This study presents the third consecutive assessment of ¹³⁷Cs activity concentrations in the same 50 moss (7 species) and lichen (2 species) sampling points in Ordu province, Türkiye, one of the most heavily contaminated areas following the Chernobyl accident. Samples were collected from exactly the same locations used in the 1997 and 2007 studies and analyzed by high‑resolution gamma spectrometry. In 2025, detectable ¹³⁷Cs was found in 14 of 30 moss sites (47%) and 3 of 20 lichen sites (15%). For samples below the minimum detectable activity (MDA), a value of MDA/2 (0.93 Bq kg⁻¹) was substituted for lichens, while moss samples below the MDA were excluded from regression. The ecological half‑life (Teco) for the 2007–2025 period was 4.38 ± 1.05 years for mosses and 4.18 ± 0.61 years for lichens. For mosses, this is nearly identical to the 1997–2007 mean (4.4 years), while for lichens it decreased from 5.6 to 4.18 years, suggesting a slight acceleration in environmental removal. All Teco values remain far shorter than the physical half‑life of ¹³⁷Cs (30 years), confirming that environmental removal processes dominate over radioactive decay. Residual ¹³⁷Cs is concentrated in higher‑altitude areas, reflecting the original deposition pattern and slower removal in cooler, more humid microenvironments. Nearly 39 years after the accident, the radiological risk posed by residual trace levels is negligible. This 28‑year dataset provides one of the longest continuous records of ¹³⁷Cs in epiphytic bioindicators and serves as a valuable baseline for future contamination events.