24-10-2012, 05:56 PM
Carcinogenicity and Immunotoxicity of Embedded Depleted Uranium and Heavy-Metal Tugsten Alloy in Rodents
ABSTRACT
This study investigates the carcinogenic and imunotoxic potential of embedded fragments of depleted uranium (DU) and
a heavy-metal tungsten alloy (WA). Male Fischer 344 rats are surgically implanted with pellets of DU, WA, tantalum (inert
metal, negative control), or nickel (known carcinogen, positive control). In Year 3 of this study, we found that implanted WA
resulted in tumors at the implantation site in 100% of the rats. These tumors developed rapidly (within 18-22 weeks) after
pellet implantation, exhibited extremely aggressive growth characteristics, and metastasized to the lung. The tumors were
identified by histopathology and immunohistochemisty as high-grade pleomorphic rhabdomyosarcomas. In addition, rats in
the high-dose WA group exhibited signs of polycythemia as early as one month after pellet implantation. Rats in the DU or
tantalum groups showed no pellet-associated tumors for up to 2 years after implantation.