Lead poisoning in cattle grazing pasture contaminated by industrial waste.

Lead poisoning is described in a herd of 120 Nelore cows of which 35 were affected. All affected cows died after a clinical course of 2-7 d with clinical signs related to cortical neurological disturbances. The source of Pb was fumes from a car battery recycling plant which has had a failure in its filtering system. Lead concentrations in liver and kidneys of 2 cows, in soil; and in grass where the cows were held were respectively 39 to 431 ppm, 147 to 431 ppm, and 245 ppm. No significant gross changes were observed. Histopathology revealed of neuronal necrosis, vacuolation of the neuropil and hypertrophy of the vascular endothelium in the cerebral cortices, degeneration of the epithelial cells of renal proximal tubules, and hemosiderosis of kidney, spleen and liver.