Journal article
A 60-year record of 129I in Taal Lake sediments (Philippines): Influence of human nuclear activities at low latitude region
Chinese Academy of Sciences1
Center for Nuclear Technologies, Technical University of Denmark2
The Hevesy Laboratory, Center for Nuclear Technologies, Technical University of Denmark3
Radioecology and Tracer Studies, Center for Nuclear Technologies, Technical University of Denmark4
National Taiwan University5
University of California at San Diego6
The influence of human nuclear activities on environmental radioactivity is not well known at low latitude region that are distant from nuclear tests sites and nuclear facilities. A sediment core collected from Taal Lake in the central Philippines was analyzed for 129I and 127I to investigate this influence in a low-latitude terrestrial system.
A baseline of 129I/127I atomic ratios was established at (2.04–5.14) × 10−12 in the pre-nuclear era in this region. Controlled by the northeasterly equatorial trade winds, increased 129I/127I ratios of (20.1–69.3) × 10−12 suggest that atmospheric nuclear weapons tests at the Pacific Proving Grounds in the central Pacific Ocean was the major source of 129I in the sediment during 1956–1962.
The 129I/129I ratios, up to 157.5 × 10−12 after 1964, indicate a strong influence by European nuclear fuel reprocessing plants. The East Asian Winter Monsoon is found to be the dominant driving force in the atmospheric dispersion of radioactive iodine (129I) from the European nuclear fuel reprocessing plants to Southeast Asia, which is also important for dispersion of other airborne pollutants from the middle-high, to low latitude regions.
A significant 129I/127I peak at 42.8 cm in the Taal Lake core appears to be the signal of the Chernobyl accident in 1986. In addition, volcanic activities are reflected in the iodine isotope profiles in the sediment core, suggesting the potential of using iodine isotopes as an indicator of volcanic eruptions.
Language: | English |
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Year: | 2017 |
Pages: | 1149-1156 |
ISSN: | 18791298 and 00456535 |
Types: | Journal article |
DOI: | 10.1016/j.chemosphere.2017.11.134 |
ORCIDs: | Hou, Xiaolin |