Alexander Ginzburg, one of five Soviet dissidents swapped for two Soviet spies, yesterday chilled a commission of House and Senate members with tales from the Soviet prison camps that he left just a fortnight ago.

Looking pale and exhausted, Ginzburg told the Commission on Security and Cooperation in Europe that human rights activists continue to struggle with Soviet authorities, even from their prisons and camps. He urged Congress and the United States to continue pressing the Soviet Union to treat its dissidents more humanely.

It was an odd encounter between 42-year-old Soviet citizen, obviously still stunned by his sudden release, and half a dozen members of the House and Senate in an ornate committee room in the Rayburn House Office Building. The room was bright with TV lights and filled with spectators.

"Having spent the last two years in isolation," Ginzburg said - a reference to the "special regime" labor camp for "especially dangerous state criminals" where he had been imprisoned, "I find it difficult to grasp all that has happened in that time. I am unaware of much that is known to those present here today.

"However, I have information unknown to those on the outside" - information from inside the Gulag Archipelago.

The commission to which Ginzberg spoke was established to monitor the Helsinki agreement on European security. Ginzburg himself was a member of the Moscow "Helsinki watch group" set up by dissident activists to monitor Soviet compliance wiht that agreement, particularly its human rights provisions.

Ginsburg gave the commission a rundown of other members of Soviet Helsinki watch groups who are still in camps or prisons, and of other Soviet human rights activists. Many of them, Ginzburg said, are extremely ill. He mentioned Serge Kovalev, a biologist in prison since 1974 who has undergone emergency surgery in camp; Oleksa Tikhy, a Ukrainian dissident who served in the same camp that Ginzburg was in and who, Ginzburg said, may already be dead, and Vladimir Osipov, a Russian nationalist dissident who suffers from tuberculosis but could not get treatment for years.

These cases "are not exceptions," Ginzburg said. "Rather they are ordinary events and typical of prison life...Stomach ulcers, tuberculosis, hypertension, kidney and liver ailments are inevitable diseases for prisoners.

"I do not know any prisoner who does not suffer from at least one of these illnesses. This is the natural result of our diet, our medicine and our punitive legislation."

Ginzburg continued: "I to stress that the mistreatment we find in camp is not the result of preverted actions on the part of individual guards. In fact, everything is done in accordance with regulations and special instructions. And that is the most terrible thing of all."

Ginzburg said the decision by Soviet authorities to exchange him and four other dissident prisoners for two Soviet spies held by the United States was a "humane act," but that it "is not an improvement of the general human rights situation in the U.S.S.R.,"

"It is just not possible that this regime will become more liberal," Ginzburg said. But later in his testimony he said external and internal pressures eventually would force a changed in the way the Soviet Union handles human rights issues.

Sens. Patrick Leahy (D.Vt.) and Bob Dole (R-Kan.) and Reps. Dante Fascell (D-Fla.) and Millicent Fenwick (R-N.J.) tried to elicit information or opinions from Ginzburg about recent events of which which he obviously had little if any personal knowledge. The four members of Congress seemed to have trouble grasping the fact that Ginzburg had been in a sort of human refrigerator for two years, cut off from most outside information.

Ginzburg expressed strong support for U.S. measures to pressure the Soviet government on human rights issues.

"I am grateful for the attention you are paying to my country," Ginzburg said. "It is important that you pay this attention, and it may also be good for the soul of America." CAPTION: Picture, Alexander Ginzburg: "I am grateful for the attention" to human rights. By James K. W. Atherton - The Washington Post