The Naturally Occurring Alfa-ray Activity of Foods

Abstract

Most of the activity is due to members of the thorium and radium series. There is a factor of 20,000 between the most active and least active foods. The most active food so far measured is the Brazil nut; breakfast cereals have the next highest a-activity. In general, values in milk products, fruits and vegetables are low. The x-activity seems to increase with the phosphorus content of foods. In general, an adequate diet will not contain less than 2 × 10−12 c of alfa/day