Effects of heavy metals and of deficiency of zinc on mortality rates in mice infected with encephalomyocarditis virus.

Salts of cadmium, lead, mercury, and nickel given orally to mice increased encephalomyocarditis virus-induced mortality rates. Although lead was the least toxic of the 4 metals, it enhanced the mortality the most. Concentrations of mercuric chloride as low as 0.01 ppm intensified the mortality; a minimal concentration that resulted in no effect was not ascertained. Zinc deficiency caused pronounced retardation of growth in young mice, but it did not influence mortality due to encephalomyocarditis virus.