The clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scale

<p>The transfer of radiocaesium (<span class="inline-formula"><sup>137</sup></span>Cs) from soil to crops is the main long-term radiation risk after nuclear accidents. The prevailing concept is that <span class="inline-formula"><sup>137&l...

Full description

Saved in:
Bibliographic Details
Main Authors: M. Vanheukelom, N. Haenen, T. Almahayni, L. Sweeck, N. Weyns, M. Van Hees, E. Smolders
Format: Article
Language:English
Published: Copernicus Publications 2025-04-01
Series:SOIL
Online Access:https://soil.copernicus.org/articles/11/339/2025/soil-11-339-2025.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849311268279681024
author M. Vanheukelom
M. Vanheukelom
N. Haenen
N. Haenen
T. Almahayni
L. Sweeck
N. Weyns
M. Van Hees
E. Smolders
author_facet M. Vanheukelom
M. Vanheukelom
N. Haenen
N. Haenen
T. Almahayni
L. Sweeck
N. Weyns
M. Van Hees
E. Smolders
author_sort M. Vanheukelom
collection DOAJ
description <p>The transfer of radiocaesium (<span class="inline-formula"><sup>137</sup></span>Cs) from soil to crops is the main long-term radiation risk after nuclear accidents. The prevailing concept is that <span class="inline-formula"><sup>137</sup></span>Cs sorption in soil – and, hence, its bioavailability – is controlled by soil clay content (0–2 <span class="inline-formula">µ</span>m). This study tested this assumption using 24 soils collected worldwide. The radiocaesium interception potential (RIP), i.e., <span class="inline-formula"><sup>137</sup></span>Cs adsorption, was measured for the bulk soils and for their clay and silt fractions. The RIP varied by a factor of 438 among soils and was <i>unrelated</i> to the clay content (<span class="inline-formula"><i>p</i></span> <span class="inline-formula">&gt;</span> 0.05). The RIP in the clay fractions was lowest for young volcanic soils with allophane and mica and for highly weathered tropical soils with kaolinite. In contrast, RIP values about 2 orders of magnitude higher were found in intermediate-weathered temperate soils dominated by illite. Soil RIP was, hence, related to soil illite content (R<span class="inline-formula"><sup>2</sup>=</span> 0.50; <span class="inline-formula"><i>p</i></span> <span class="inline-formula">&lt;</span> 0.001). A significant fraction of soil RIP originated from clay minerals embedded in the silt fraction. The sum of RIP in clay and silt fractions overestimated the soil RIP by, on average, a factor of 2, indicating that the isolation of clay opens selective <span class="inline-formula"><sup>137</sup></span>Cs sorption sites inaccessible in intact soils. Soil mineralogy, not just clay content, governs soil RIP. In terms of validity, existing <span class="inline-formula"><sup>137</sup></span>Cs bioavailability models require recalibration for use on a global scale.</p>
format Article
id doaj-art-c63b867e4a3a47759475e5c0adccca78
institution Kabale University
issn 2199-3971
2199-398X
language English
publishDate 2025-04-01
publisher Copernicus Publications
record_format Article
series SOIL
spelling doaj-art-c63b867e4a3a47759475e5c0adccca782025-08-20T03:53:27ZengCopernicus PublicationsSOIL2199-39712199-398X2025-04-011133936210.5194/soil-11-339-2025The clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scaleM. Vanheukelom0M. Vanheukelom1N. Haenen2N. Haenen3T. Almahayni4L. Sweeck5N. Weyns6M. Van Hees7E. Smolders8Biosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, Mol, 2400, BelgiumDivision of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, Leuven, 3001, BelgiumBiosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, Mol, 2400, BelgiumDivision of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, Leuven, 3001, BelgiumBiosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, Mol, 2400, BelgiumBiosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, Mol, 2400, BelgiumDivision of Geology, KU Leuven, Celestijnenlaan 200e – P.O. Box 2411, Leuven, 3001, BelgiumBiosphere Impact Studies, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, Mol, 2400, BelgiumDivision of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, Leuven, 3001, Belgium<p>The transfer of radiocaesium (<span class="inline-formula"><sup>137</sup></span>Cs) from soil to crops is the main long-term radiation risk after nuclear accidents. The prevailing concept is that <span class="inline-formula"><sup>137</sup></span>Cs sorption in soil – and, hence, its bioavailability – is controlled by soil clay content (0–2 <span class="inline-formula">µ</span>m). This study tested this assumption using 24 soils collected worldwide. The radiocaesium interception potential (RIP), i.e., <span class="inline-formula"><sup>137</sup></span>Cs adsorption, was measured for the bulk soils and for their clay and silt fractions. The RIP varied by a factor of 438 among soils and was <i>unrelated</i> to the clay content (<span class="inline-formula"><i>p</i></span> <span class="inline-formula">&gt;</span> 0.05). The RIP in the clay fractions was lowest for young volcanic soils with allophane and mica and for highly weathered tropical soils with kaolinite. In contrast, RIP values about 2 orders of magnitude higher were found in intermediate-weathered temperate soils dominated by illite. Soil RIP was, hence, related to soil illite content (R<span class="inline-formula"><sup>2</sup>=</span> 0.50; <span class="inline-formula"><i>p</i></span> <span class="inline-formula">&lt;</span> 0.001). A significant fraction of soil RIP originated from clay minerals embedded in the silt fraction. The sum of RIP in clay and silt fractions overestimated the soil RIP by, on average, a factor of 2, indicating that the isolation of clay opens selective <span class="inline-formula"><sup>137</sup></span>Cs sorption sites inaccessible in intact soils. Soil mineralogy, not just clay content, governs soil RIP. In terms of validity, existing <span class="inline-formula"><sup>137</sup></span>Cs bioavailability models require recalibration for use on a global scale.</p>https://soil.copernicus.org/articles/11/339/2025/soil-11-339-2025.pdf
spellingShingle M. Vanheukelom
M. Vanheukelom
N. Haenen
N. Haenen
T. Almahayni
L. Sweeck
N. Weyns
M. Van Hees
E. Smolders
The clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scale
SOIL
title The clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scale
title_full The clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scale
title_fullStr The clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scale
title_full_unstemmed The clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scale
title_short The clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scale
title_sort clay mineralogy rather than the clay content determines radiocaesium adsorption in soils on a global scale
url https://soil.copernicus.org/articles/11/339/2025/soil-11-339-2025.pdf
work_keys_str_mv AT mvanheukelom theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT mvanheukelom theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT nhaenen theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT nhaenen theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT talmahayni theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT lsweeck theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT nweyns theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT mvanhees theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT esmolders theclaymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT mvanheukelom claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT mvanheukelom claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT nhaenen claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT nhaenen claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT talmahayni claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT lsweeck claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT nweyns claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT mvanhees claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale
AT esmolders claymineralogyratherthantheclaycontentdeterminesradiocaesiumadsorptioninsoilsonaglobalscale