The effect of arsenic (7440382) on the toxicity of selenium (7782492) was investigated in rats. Rats were fed diets containing 11 parts per million (ppm) selenium in wheat. Animals were divided into groups given drinking water containing 5ppm tungsten (7440337), fluorine (7782414), molybdenum (7439987), arsenic, chromium (7440473), vanadium (7440622), cadmium (7440439), zinc (7440666), cobalt (7440484), uranium (7440611), or nickel (7440020). Additional groups received selenium diet with no elements in drinking water or distilled water and a selenium free diet. Differences in weight and food consumption were noted. Survivors were killed on day 130 and examined for liver damage. By day 60, there was an increase in mortality rate in rats given fluorine, molybdenum, chromium, cadmium, vanadium, zinc, cobalt, and uranium. All rats in the tungsten and arsenic groups were living and normal in appearance on day 60. Examination of livers of rats fed selenium alone, selenium with nickel, and of controls were normal. Liver concentrations of selenium in the group given arsenic were much lower than in other groups, except for the one surviving rat given vanadium. None of the rats given tungsten had any appreciable liver damage. Rats were given selenium and 2.5ppm arsenic or tungsten in water for 75 days and autopsied. Arsenic partially prevented liver damage in rats fed selenium; they consumed more food and grew more rapidly than rats not given arsenic. Tungsten had no effect in preventing the symptoms of selenium poisoning, but rats given tungsten with selenium lived longer than those given selenium alone.
