title: Inhalation of uranium nanoparticles: respiratory tract deposition and translocation to secondary target organs in rats.
abstract: Uranium nanoparticles (<100 nm) can be released into the atmosphere during industrial stages of the nuclear fuel cycle and during remediation and decommissioning of nuclear facilities. Explosions and fires in nuclear reactors and the use of ammunition containing depleted uranium can also produce such aerosols. The risk of accidental inhalation of uranium nanoparticles by nuclear workers, military personnel or civilian populations must therefore be taken into account. In order to address this issue, the absorption rate of inhaled uranium nanoparticles needs to be characterised experimentally. For this purpose, rats were exposed to an aerosol containing 10⁷ particles of uranium per cm³ (CMD=38 nm) for 1h in a nose-only inhalation exposure system. Uranium concentrations deposited in the respiratory tract, blood, brain, skeleton and kidneys were determined by ICP-MS. Twenty-seven percent of the inhaled mass of uranium nanoparticles was deposited in the respiratory tract. One-fifth of UO₂ nanoparticles were rapidly cleared from lung (T(½)=2.4 h) and translocated to extrathoracic organs. However, the majority of the particles were cleared slowly (T(½)=141.5 d). Future long-term experimental studies concerning uranium nanoparticles should focus on the potential lung toxicity of the large fraction of particles cleared slowly from the respiratory tract after inhalation exposure.
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire, IRSN/PRP-HOM/SRBE, Laboratoire de Radiotoxicologie Expérimentale, BP 166, 26702 Pierrelatte Cedex, France. fabrice.petitot@irsn.fr
authors.forename: Fabrice
authors.initials: F
authors.lastname: Petitot
authors.forename: Philippe
authors.initials: P
authors.lastname: Lestaevel
authors.forename: Elie
authors.initials: E
authors.lastname: Tourlonias
authors.forename: Charline
authors.initials: C
authors.lastname: Mazzucco
authors.forename: Sébastien
authors.initials: S
authors.lastname: Jacquinot
authors.forename: Bernadette
authors.initials: B
authors.lastname: Dhieux
authors.forename: Olivia
authors.initials: O
authors.lastname: Delissen
authors.forename: Benjamin B
authors.initials: BB
authors.lastname: Tournier
authors.forename: François
authors.initials: F
authors.lastname: Gensdarmes
authors.forename: Patricia
authors.initials: P
authors.lastname: Beaunier
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dublineau
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D008297:Male; D013058:Mass Spectrometry; D053768:Metal Nanoparticles / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D012137:Respiratory System / Q000187:drug effects / Q000378:metabolism*; D018709:Statistics, Nonparametric; D014501:Uranium / Q000493:pharmacokinetics* / Q000633:toxicity*
chemical_list: D014501:Uranium