title: A Monte Carlo analysis of possible cell dose enhancement effects by uranium microparticles in photon fields.
abstract: Uranium microparticles (radii: 50 nm-1.25 μm) were modelled surrounded by tissue and exposed to natural background radiation, in order to investigate potential dose enhancements from photon interactions. Generally, the results depended on the microparticle size. For a 0.5 μm radius microparticle in an isotropic field, it was found that the combined photon/electron doses deposited in 1 and 10 μm radii shells around it were raised by factors of ∼3.8 and ∼1.1, respectively; for a typical background photon fluence rate, these would correspond to increased energy depositions of a few 10s and a few 100s of eV y(-1), which are far less than the likely deposition rate resulting from the radioactive decay of a (238)U microparticle. The health hazard from uranium microparticle interactions with background photons was concluded to be negligible.
authors.affiliation: Health Protection Agency, Chilton, Didcot, Oxon OX11 0RQ, UK. jonathan.eakins@hpa.org.uk
authors.forename: J S
authors.initials: JS
authors.lastname: Eakins
authors.forename: J Th M
authors.initials: JT
authors.lastname: Jansen
authors.forename: R J
authors.initials: RJ
authors.lastname: Tanner
mesh_terms: D002468:Cell Physiological Phenomena / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects; D003198:Computer Simulation; D018499:Linear Energy Transfer / Q000502:physiology*; D008863:Microspheres; D008954:Models, Biological; D008956:Models, Chemical; D015233:Models, Statistical; D009010:Monte Carlo Method; D017785:Photons; D011829:Radiation Dosage; D014501:Uranium / Q000737:chemistry*
chemical_list: D014501:Uranium