text: In 1958, research for project SUNSHINE was brought to Belgium. Scientists started doing tests that were slightly different than those done previously in the United States and Europe by analyzing soils in agricultural regions instead of human bones. They headed in two main directions: environmental  surveys and experimental research in natural and in controlled conditions. Their goal was to see the effect of Strontium-90 in the soils as well as to see how it transferred to the grass and grazing animals such as cows and sheep, the animals from which humans consume milk and meat. Researchers also looked for direct influences of strontium-90 by observing how well the contaminated grass and crops grew.
  In a 1957 article, Dr. Whitlock, director of Health Education in the National Dairy Council, Chicago, Illinois, discussed the impact of strontium-90 in the cow milk consumed by humans, concluding that the effects of Sr-90 would not be detectably harmful to the general populace of the US. "From the foregoing information, it would seem we have a long way to go before the presence of Strontium-90 in milk and other foods can catch up with the amounts of radioactivity to which we have long been exposed through natural resources." Specifically referring to the natural radioactivity one is exposed to from potassium-40."