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University of Rochester Medical Lab

The Rochester Experiments were conducted at the University of Rochester Metabolism Ward from 1943 to 1947 to better understand the effects of radioactive isotopes on the human body.

The Manhattan Project was at the forefront of not only physics, but biology as well. Stafford Warren, a faculty member of the Department of Radiology at the University of Rochester, was chosen to head up the Manhattan Project’s medical division. Warren was tasked with researching worker safety needs and setting a new industrial standard.

Warren and his team developed new instruments to monitor plant workers and to measure radiation’s effect on the human body. As part of the studies, at least 22 human subjects were injected with either plutonium, radium, polonium, uranium, or lead. The experiments required low amounts of radioactive isotopes and were performed in a controlled environment.

The ethics of the Rochester Experiments are hotly debated. Before the experiment, all subjects were patients of the university’s metabolism ward and were chosen by doctors who “believed [they] would benefit from additional time in the hospital.” These patients were classified as terminally ill, but most likely suffered from chronic medical conditions.

Patient consent is unclear, as no written records were kept. The medical effects are inconclusive as well, as patient cases were rarely followed up on. Relatives of the test subjects came forward in the 1990s with claims that their loved ones were “pushed” to see doctors associated with the experiments, who they referred to as “monsters.”

The site is now the home of the award-winning teaching hospital Strong Memorial, accommodating approximately 886 acute inpatients and over 39,000 annual admissions as of 2025.

The U.S. Department of Energy Office of Legacy Management’s Formerly Utilized Sites Remedial Action Program maintains an online Considered Sites Database that provides digital access to some 1,500 key documents related to sites that supported the Manhattan Project and the U.S. Atomic Energy Commission, including the University of Rochester Medical Lab .

Manhattan Project National Historical Park

Last updated: November 19, 2025