The Clinton administration is being pressed to delve yet deeper into the record of federal research using human subjects, perhaps opening a comprehensive review of the nation's research ethics during the past half-century.

It began as a discussion of radiation experiments related to the nuclear weapons program during the Cold War and was promoted by Energy Secretary Hazel R. O'Leary as part of an initiative to reveal her agency's atomic secrets. But it has already expanded to include radiation experiments conducted by several agencies and involving thousands of subjects.Last week the administration promised a thorough search of records by the Energy Department, the Defense Department, NASA, the CIA and federal health agencies on research involving human subjects who were exposed to radiation, often without their knowledge. Many of the experiments were done for medical reasons, not in the name of national security.

Although much about the research has been known in academic and scientific circles for decades, its troubling history is only now getting widespread public recognition, in part because the administration has pledged an investigation.

Now, politicians and public interest groups are beginning to suggest that fully understanding that research may call for an examination that focuses not just on radiation but on broader ethical questions.

On Thursday, Sen. John Glenn, C-Ohio, who is chairman of the Governmental Affairs Committee, said he would schedule hearings into the testing, and he called for a full investigation of all human experiments up to the present day.

"Let me make myself clear that I am talking about more than radiation testing," Glenn said. "I am calling for a government-wide review of all testing programs, from drug tests at the Food and Drug Administration to military tests at the Defense Department, to determine if any improper experiments on humans persist to this day."

Any such sweeping inquiry might encompass everything from the training of astronauts to the testing of pesticides, from development of defenses against biological weapons to the front lines of the war on cancer, from the health hazards of nuclear-bomb fallout in the Pacific islands to the testing of mustard gas on young recruits during World War II.

In the past week, demands for such an inquiry have come from several quarters, motivated by a variety of impulses: an urge to confront questions that were put deep in some bureaucratic closet even when information was made public in the past; an interest in speeding compensation to people who may have been injured, and not just by the radiation experiments that sparked the most recent outcry; a nagging worry, so far unsubstantiated, about whether any improper research is being conducted even today.