From radioactive fallout to chemical-biological warfare experiments, the U.S. government took a very casual and careless approach to what it did to its own citizens during the 1950s and 1960s. Human cancer and thousands of sheep deaths were just some of the results. The evidence of such shocking behavior just keeps piling up.

As Lee Davidson, Deseret News Washington bureau chief, reported this past week, the Army tried out germ warfare on its own troops in the Utah desert in 1955 and 1956, dropping an aerosol on volunteer soldiers in the field that caused "Q fever" - resulting in high fever, headache and a form of pneumonia. No deaths were reported, but the operation was a carefully kept secret.A recently proposed laboratory at Dugway to manufacture aerosols from the Q fever bacteria - in order to test protective gear - has been delayed because watchdog groups have been concerned about the accidental release of such disease into the environment.

And it now turns out that instead of an accidental release, the bacteria has already been deliberately sprayed in the open air - and on guinea pig soldiers - years ago.

At least the soldiers were "volunteers." In another Dugway-run biological warfare experiment in 1957 and 1958, potentially toxic fluorescent particles were sprayed from aircraft over hundreds of miles east of the Rocky Mountains to study the behavior of particles released in clouds. Other similar tests may have been done later.

The zinc cadmium oxide particles, especially in the quantities used by the Army, are known to be dangerous. When ingested, they can accumulate in human tissue with toxic results. Any sickness caused by the testing is unlikely to have been identified at the time.

Those who approved such tests must have been incredibly naive or alarmingly callous - or some combination of both.

What's troubling is not only the decision to expose people to possibly harmful agents but the decision to keep it secret. That suggests that those in charge knew what they were doing was wrong.

Most of what has been found out has not come from voluntary release of information by the government, even after all these years, but by forcing the disclosure through the Freedom of Information law.

Yet the law is helpful only when one knows what one is seeking. One wonders what other mischief was performed on an unsuspecting population - with the answers hidden in dusty archives.