Nephrotoxicity effects of the wood preservative chromium copper arsenate on mice: histopathological and quantitative approaches.

Chromium copper arsenate (CCA) was used for the protection of wood building materials until the restriction by EPA in 2002. During a short period of time 14-24h, a comparative nephrotoxicity study was performed regarding the effects of CCA and its compounds per se. Histopathological and histochemical features were correlated with the concentration of the total arsenic and chromium in mice kidney. Animals were subcutaneously injected with CCA (7.2mg/kg arsenic and 10.2mg/kg chromium per body weight), CrO3 (10.2mg/kg), As2O5 (7.2 mg/kg) and NaCl (0.9%) per se. The histopathological examination of the renal sections evidenced acute tubular necrosis in the groups of animals exposed to CCA (in both periods of time). Although the same contents of pentavalent arsenic and hexavalent chromium were injected in treated animals with CCA and with the prepared solutions of As2O5 and CrO3, the arsenic concentration on kidneys of CCA-exposed animals was much higher than those in animals exposed to As2O5 (32- and 28-fold higher at 14 and 24h, respectively). However, the elimination of chromium seems to occur similarly in the kidneys of animals treated with CCA and CrO(3)per se. Interactions among the components of CCA result in a marked decrease of the ability of kidney to eliminate simultaneously both analytes. The nephrotoxicity of CCA was higher than its components per se, evidencing a possible synergetic effect.