[Effect of contamination of drinking water with sodium fluoride on the alkaline phosphatase activity of peripheral granulocytes in the rat].

During a 4-week administration of water contaminated with sodium fluoride in doses of 20 mg/kg of body weight and above, decreased activity of granulocytes alkaline phosphatase and increased count of leucocytes in peripheral blood were found. This may be indicative of a toxic effect of high doses of sodium fluoride on the leucocytic system. Thus, observation of those parameters in people and animals from the area surrounding the factories, contaminated by fluorine compounds, seems advisable.