The concentration of cadmium (Cd) in kidney (A), liver (B), blood (C), and brain (D) following exposure of Wistar rats to saline, Cd only, cadmium and mercury (Cd + Hg), or mercury, cadmium, lead, and arsenic (Hg + Cd + Pb + As). *, significantly different (p < 0.05) than the mean of the corresponding group of rats exposed to saline. +, significantly different (p < 0.05) than the mean of the corresponding group of rats exposed to Cd only.