Comment on the Capstone Depleted Uranium (DU) Aerosol Characterization and Risk Assessment Study.

Dear Editors: WE NOTED that nowhere in the issue of Health Physics, March 2009, devoted to “The Capstone Depleted Uranium (DU) Aerosol Characterization and Risk Assessment Study” (Parkhurst and Guilmette 2009) were nanoparticles considered or even mentioned. The smallest particles considered were approximately 0.7 m in diameter (Holmes et al. 2009). Perhaps DU atoms may have entered the brain via olfactory pathways (Tjälve and Henriksson 1999) or carbon nanoparticles, i.e., buckyballs or fullerenes (Kroto et al. 1985), may have been produced when DU burned as the armor piercing shells struck a target (Krupka et al. 2009). Recent research has indicated the possibility of nanotoxicity to the lung and via lungs to other body compartments. (Oberdörster et al. 2005). One may ask, is it possible that the carbon fullerenes could also capture individual DU molecules that can be taken in the nasal mucosa and transported through the olfactory nerve further into the brain (Persson et al. 2003; Dorman et al. 2009)?