Radiation Measurements 43 (2008) 698 – 703 www.elsevier.com/locate/radmeas Invited paper Physical dosimetric reconstruction of a radiological accident due to gammagraphy equipment that occurred in Dakar and Abidjan in summer 2006 I. Clairand ∗ , C. Huet, F. Trompier, J.-F. Bottollier-Depois Institute for Radiological Protection and Nuclear Safety (IRSN), Radiological Protection and Human Health Division, External Dosimetry Department, B.P. 17, 92262 Fontenay-aux-Roses, France Abstract A severe irradiation accident, due to gammagraphy equipment containing an 192 Ir radioactive source, involving several victims occurred from the 3 June to 3 August 2006 in two African subsidiaries of the French group Bureau Veritas. This article retraces the circumstances of the accident and the physical dosimetric reconstruction made by IRSN on four patients treated in France. The dose reconstruction was based on numerical simulations and electron paramagnetic resonance (EPR) measurements performed on bone tissue and tooth enamel samples. The data obtained by physical dosimetry, as complementary elements to biological dosimetry and clinical observations, were helpful for the treatment strategy implemented by the medical team. © 2008 Elsevier Ltd. All rights reserved. Keywords: Radiological accident; Physical dose reconstruction; Monte Carlo calculations; EPR 1. Introduction A severe irradiation accident involving several victims took place between 3 June and 3 August 2006 in subsidiaries of the French group Bureau Veritas located in Senegal and in Côte d’Ivoire. The French Institute for Radiological Protection and Nuclear Safety (IRSN) (Fontenay-aux-Roses, France) recom- mended to Bureau Veritas to have the most severely irradiated individuals hospitalised at the French Percy Military Training Hospital (Clamart, France), a specialist establishment with ex- perience recognised internationally in treating accidental irra- diations. Four patients were admitted to this hospital between 29 and 31 August. The purpose of a physical dosimetric reconstruction in case of an accident of this nature is to estimate as accurately as pos- sible the dose received and its distribution within the organism so that physicians may fine tune their diagnosis and prescribe the most suitable treatment. Such a physical dosimetry, sev- eral times carried out in the laboratory in case of radiological accidents that occurred these last years (Clairand et al., 2006; ∗ Corresponding author. Tel.: +33 158 358 965; fax: +33 147 469 777. E-mail address: isabelle.clairand@irsn.fr (I. Clairand). 1350-4487/$ - see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.radmeas.2007.12.051 Trompier et al., 2007; Huet et al., 2007; Huet et al., 2008), is complementary to data produced by clinical and biological dosimetry. The strategy adopted to reconstruct the dose received by individuals using physical means was based on two comple- mentary techniques: (1) numerical simulation techniques using a Monte Carlo calculation code to estimate the dose distribu- tions within a numeric anthropomorphic phantom modelling the victim placed in the accident environment and (2) measure- ments of doses received in teeth or bone samples from victims using the electronic paramagnetic resonance (EPR) spectrome- try technique. These dosimetric techniques were adapted indi- vidually to each of the four patients based on the knowledge of the scenario and the type of sample available and measurable using the EPR techniques. This article traces the circumstances of the accident before presenting the approach and dosimetric results obtained for each patient individually. 2. Description of the circumstances of the accident On 3 June 2006, in Dakar, during a gammagraphy op- eration performed by Bureau Veritas employees on a site