Availability to Man of Strontium in Cow's Milk

A double tracer method has been used to measure the availability-of strontium in cow's milk. Thus, strontium-87m as a dilute aqueous solution of strontium chloride was added to milk from a cow which had Received strontium-85 intravenously. Urines were collected from 6 adult volunteers after ingestion of this milk mixture. It is shown that the availability of strontium in the milk is equal to that of strontium as chloride in dilute aqueous solution. The consequences of the result upon the specific activity of strontium-90 from fallout in certain body pools are discussed.