Impact of alpha self-absorption on personal air sampling in NORM operations
Author Identifier (ORCID)
Gregory S. Hewson: https://orcid.org/0009-0002-0872-9288
Martin I. Ralph: https://orcid.org/0000-0002-5893-6886
Marcus Cattani: https://orcid.org/0000-0002-7586-7288
Abstract
Personal air sampling (PAS) is used to assess worker intake of airborne radioactivity in operations processing minerals containing naturally occurring radionuclides. Subsequent alpha particle counting of the PAS filter may be affected by self-absorption of the alpha particles in the dust matrix or filter, depending on the dust loading on the filter and the size of particles collected. This review investigates the potential for self-absorption on air sampling filters via a literature review and by applying a formula to correct past PAS data from the mineral sand industry. The findings indicate that PAS estimates of intake were consistently under-stated by at least 40% across work categories engaged in the operation and maintenance of mineral sand separation plants. An alpha particle self-absorption greater than 50% was derived when dust loading on the PAS filter exceeded 3 mg·cm-2. The findings demonstrate that historical PAS data in industries where self-absorption effects are neglected can substantially underestimate worker radionuclide intakes and doses, with important implications for retrospective dose assessment.
Keywords
Airborne radioactivity, alpha self-absorption, dose assessment, mining, natural radiation, personal air sampling
Document Type
Journal Article
Date of Publication
2-9-2026
Volume
46
Issue
1
PubMed ID
41610443
Publication Title
Journal of Radiological Protection
Publisher
IOP
School
School of Medical and Health Sciences
RAS ID
88862
Copyright
subscription content
Comments
Hewson, G. S., Ralph, M. I., & Cattani, M. (2026). Impact of alpha self-absorption on personal air sampling in NORM operations. Journal of Radiological Protection, 46, 012502. https://doi.org/10.1088/1361-6498/ae3f3e