More experiments at:

http://www.rps.psu.edu/mar96/science.html

An excerpt:

"Each of these experiments was sponsored by the federal government. In most cases, participation was unwitting: patients had no knowledge that they were being subjected to experimental radiation. In all, there were over 4,000 federally sponsored radiation experiments conducted between 1944 and 1974, when the Department of Health, Education, and Welfare issued rules for protecting human subjects in government-sponsored research. The patients involved numbered in the tens of thousands."

A site that will really open your eyes:

http://www.geocities.com/afrika7_2000/