Toxic Effects of Trace Elements on the Reproduction of Mice and Rats

Abstract Breeding mice and rats were exposed to low doses of six trace elements in drinking water in an environment controlled as to contaminating trace metals. Each group was carried through three generations. Compared to control mice given only doubly deionized wafer, selenafe (3 ppm selenium) resulted in excess deaths before weaning, runts, and failures to breed. Lead (25 ppm) and cadmium (10 ppm) resulted in loss of the strain in two generations with many abnormalities. Molybdate (10 ppm molybdenum) was slightly toxic in this respect, and arsenic resulted only in elevated ratios of males to females. In rats, lead was very toxic, and titanium and nickel moderately toxic, resulting in many early deaths and runts. This method provides fairly rapid estimates of innate toxicities of trace elements in doses tolerable for growth and survival.