The state of Pennsylvania and the utility that runs the Three Mile Island nuclear plant turned down a U.S. surgeon general's recommendation that plant workers be given medicine to ward off possible cancer of the thyroid caused by radioactive iodine.

The state and tht utility also rejected a recommendation that the medicine be made "personally available" to people living in a raius of 10 miles from Three Mile Island. This recommendation was made by the surgical general because a release of radioactive iodine from Three Mile Island can come with less than a 30-minute warning.

On Wednesday, the Food and Drug Administration arranged the shipment of 259,000 bottles of potassium iodide to Pennsylvania, where they were stored in a warehouse in Middletown, near Three Mile Island. If taken before being dosed with radioactive iodine, potassium iodide settles in the thyroid and blocks the throat gland from absorbing the radioactive iodine.

The same, day, Health, Education and Welfare Secretary Joseph A. Califano, Jr. sent a memorandum to the White House urging that the potassium iodide be given immediately to the 225 workers at Three Mile Island already exposed to low doses of iodine-131. The memorandum was signed by Surgeon General Julius B. Richmond, National Institutes of Health Director Donald Frederickson and FDA Commissioner Donald Kennedy.

The memo explained that even if taken after being dosed with radioactive iodine the potassium iodide is helpful in preventing the radioactivity from damaging the thyroid.

The memo also recommended that the potassium iodide be distributed free to the 130,000 people living in a 10-mile radius of Three Mile Island. While not urging that they take the medicine, the meo recommended they have it in their possession in case there were a large escape of radioactive iodine from Three Mile Island.

The White House, through presidential assistant Jack Watson, passed the memo on to Pennsylvania Gov. Richard Thornburgh and executives of Metropolitan Edison Co. For still unexplained reasons, the governor and the utility have not given the medicine to the Three Mile Island workers and have not distributed it to residents in the 10-mile radius.

Federal sources speculate that Thornburgh and Metropolitan Edison fear that distribution of the medicine might trigger a panic. Thornburgh's office has been very cautious in dealing with the accident, which leads federal sources to suggest his rejection of the surgeon general's recommendation is part of that caution.

Neither the state or the company had any comment on this speculation. Metropolitan Edison yesterday refused to comment on any questions put to it.

In his memo to the White House, Califano said part of the reason for the recommendations is that a radioactive iodine release might take place without any kind of warning to people living nearby and downwind.