In both Washington and Oregon state prisoners, prisoners were used in radiation experiments, and then castrated (to, in the words of the doctors who ordered the castrations, “keep from contaminating the general population with radiation-induced mutants”). Dr. Joseph Hamilton, one of the doctors who oversaw the experiments said that the experiments “had a little of the Buchenwald touch”.
From 1960 to 1971 Dr. Eugene Sanger performed radiation experiments on 88 poor, black Americans. He forged consent forms, and did not tell them what he was doing (they thought they were getting medical care). He exposed their chests to 100 rads of radiation (the equivalent of about 7500 x-rays), which caused intense pain, vomiting, and blooding from their nose and ears. All but one of the patients died.
For more examples of human experimentation in the U.S., with a large body of quality references, see “Unethical Human Experimentation in the United States“