The sickening revelations continue.

This week it was just a different school. More innocent retarded children, more overzealous scientists, more radioactivity, more unethical experiments.

Harvard University has so far been concretely linked to experiments with radiation on human subjects at two Massachusetts schools for the retarded. A handful of Harvard Medical School faculty were the culprits.

This week's latest revelation--that Harvard doctors used children as young as one-year-old in a Wrentham State School experiment to determine the human thresh-old for nuclear fallout--is particularly gutwrenching.

Advocates for the retarded have even likened the research to the Nazi atrocities of World War II.

And there are more revelations to come.

The Fernald State School in Waltham has been the early flashpoint. The late Harvard faculty member Dr. Clemens E. Benda fed children milk with radioactive tracers with their breakfast cereal as part of a nutrition study in the 1950s.

This much, the University and state officials have acknowledged. But news of other radioactive experiments at Fernald, which was used as a virtual colony for Harvard scientists in the 1940s, '50s and '60s, is just starting to break.

Yesterday, the Nuclear Regulatory Commission announced that a review of its files showed that Fernald was issued a license for another radiation research project in 1966.

It is not yet known if Harvard, which had extremely close ties to Fernald at that time, was involved in the 1966 research.

The Nuclear Regulatory Commission documents included references to a requirement for parent-guardian consent. No other details about the tests were given.

The 1962 experiment at the Wrentham State School and the 1966 license for a two-year study are being scrutinized by the state's Department of Mental Retardation's task force, which was created to look into experiments on retarded children in the Cold War era.

Harvard, which has created a similar panel of its experts, will also look into the Wrentham experiment, according to Walter H. Abelmann, the committee chair. And if University scientists were involved the 1966 license is likely to draw the panel's attention.

In all, there were 43 cases prior to 1975 of NRC-sanctioned radiation testing on human subjects.

That means eventually, the investigations will end. All the experiments will be known, Most of the victims will be tracked down.