Hair Dosimetry Following Neutron Irradiation

Abstract

Use of hair as a biological dosimeter of neutron exposure was proposed a few years ago. To date, the (32)S(n,p)(32)P reaction in hair with a threshold of 2.5 MeV is the best choice to determine the fast neutron dose using body activation. This information is essential with regards to the heterogeneity of the neutron transfer to the organism. This is a very important parameter for individual dose reconstruction from the surface to the deeper tissues. This evaluation is essential to the adapted management of irradiated victims by specialized medical staff. Comparison exercises between clinical biochemistry laboratories from French sites (the CEA and COGEMA) and from the IRSN were carried out to validate the measurement of (32)P activity in hair and to improve the techniques used to perform this examination. Hair was placed on a phantom and was irradiated at different doses in the SILENE reactor (Valduc, France). Different parameters were tested: variation of hair type, minimum weight of hair sample, hair wash before measurement, delivery period of results, and different irradiation configurations. The results obtained in these comparison exercises by the different laboratories showed an excellent correlation. This allowed the assessment of a dose-activity relationship and confirmed the feasibility and the interest of (32)P measurement in hair following fast neutron irradiation.

The METREPOL criteria—are they still relevant?

“…Protocols that rely on clinical findings and/or peripheral blood cell counts such as METREPOL are currently the most practical means for large-scale dosimetry. However, some authors propose screening methods based on high-accuracy biodosimetry, such as in vivo electron paramagnetic resonance dosimetry of tooth and nail tissue for triage during a catastrophic nuclear event [11] or after a criticality accident in particular. In addition, high-accuracy biodosimetry as 32 P dosage in integument sampling and 24 Na dosage in the blood can be used to assess dose and dose distribution in the context of a criticality accident [12,13].…”

Basic concepts of radiation emergency medicine

“…In the rare case of a criticality accident, other examinations have to be rapidly carried out for dose and dose distribution assessment in the body: integument sampling ( 32 P dosage) and 24 Na (total body and dosage in the blood) [37,47].…”

Reactor accident chemistry an update

“…One option is to wear or carry an object which will undergo neutron activation for example the late John Pecket told me that at Harwell he wore an accident dosimeter which included a vial of sulphur which would have helped reconstruct fast neutron exposure in the event of a criticality accident. Another thing which could be used would be hair (Lebaron-Facobs et al, 2007), fingernail and toenail clippings. These parts of the body contain a sulphur rich protein which could be examined for radioactivity ( 32 P).…”