There have been horror stories in the past of the U.S. conducting experiments on unwilling (and/or unaware) human participants, but one that stands out is Project 4.1, in part because the ripples are still being felt (and possibly perpetuated) today.
According to the documentary Nuclear Savage (60/79 min) in 1954, the largest nuclear test conducted by the U.S. happened near the island of Rongelap, part of the Marshall Islands. On Rongelap were thousands of inhabitants who were exposed, both to the acute radiation immediately after the blast, and for several decades after, when they were sent back to live on the still-contaminated island.
The U.S. government has said that the exposure was accidental, and that the U.S. has been fair in how they’ve handled the aftermath. Marshall Islanders say that there is proof the exposure was intentional and part of a deliberate plan using them as human test subjects for more than 30 years, without their consent.
Through historical footage, interviews, and declassified documents, Nuclear Savage touches on the U.S.’s nuclear testing program and tells the story of the Rongelap islanders, and their long struggle to achieve justice for what befell them.