IN assessing margins of safety and possible toxic hazards from fluorides, it is necessary to consider the body's total intake of fluoride from all sources. This consideration is important when determining the optimum level of fluoride for dental protection before embarking on a scheme for the fluoridation of a water supply, and it is necessary also when considering possible hazards from fluorides to the community in the vicinity of industries emitting them. The total intake will be derived in part from the diet, in part from drinking water, and in part from the atmosphere. McClure (1) made a comprehensive analysis of the fluoride content of individual foods and estimated the adult intake from the diet, excluding that derived from drinking water, was 0.2-0.3 mg. per day. Cholak (2), as a result of the analyses of actual dietaries, calculated an intake of 0.34-0.80 Dr. Martin is a senior medical officer in the British Department of Health and Social Security and secretary of that department's Fluoridation Research Committee. Mrs. Jones is a member of the Food Science Advice Branch of the British Ministry of Agriculture, Fisheries and Food. This paper is based on one given at the annual meeting of the Air Pollution Control Association at St. Louis, Mo., in June 1970. Tearsheet requests to