Surface distributions of 228 Ra in seas and oceans globally: Implications for water circulation and contaminant transport.

Autor: Inoue M; Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Wake O-24, Nomi, Ishikawa, 923-1224, Japan. Electronic address: i247811@staff.kanazawa-u.ac.jp.
Jazyk: angličtina
Zdroj: Journal of environmental radioactivity [J Environ Radioact] 2024 Sep; Vol. 278, pp. 107468. Date of Electronic Publication: 2024 Jun 08.
DOI: 10.1016/j.jenvrad.2024.107468
Abstrakt: Seawater movements are challenging to track and monitor for the transport of various soluble materials. Since the 1960s, naturally occurring radium isotopes (Ra), particularly 228 Ra, with a half-life of 5.75 y, have provided unique insights into oceanic seawater circulations within a 30 y timescale. Since the 1980s, especially in the 2000s, frequent research expeditions and improvements in analytical techniques have enabled the determination of fine-scale lateral variations in 228 Ra/ 226 Ra ratio and 228 Ra concentration. These results describe ocean-, sea-, and basin-scale seawater circulations and current mixing, including seasonal variations. Additionally, the source areas of Ra in seawater (i.e., coastal and shallow shelf areas) often overlap with areas containing contaminants released by human activities. Notably, the surface current systems inferred from the distribution of 228 Ra closely explained the transport patterns of radiocesium derived from the Fukushima Dai-ichi Nuclear Power Plant. Databases of 228 Ra/ 226 Ra ratios and 228 Ra concentrations have the potential to predict flow pathways and timescales for various soluble contaminants in ocean and sea environments.
Competing Interests: Declaration of competing interest The authors declare no conflict of interest.
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Databáze: MEDLINE
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