When the Army in 1957 ordered ground troops into an atomic test area in Nevada only two hours after a 44-kiloton bomb was exploded, one major purpose was public relations, according to a report furnished by the Pentagon.

At least two of the soldiers have since developed leukemia - cancer of the blood cells.

The unclassified report, which a Pentagon spokesman said was prepared in 1957 by Sixth Army headquarters, lists as a purpose of the Army troop test: "To portray to the public the Army at its best employing [lits new Pentomic] organization in operations under atomic warfare conditions . . ."

Nicknamed "Smokey," the esercise was filmed by Army cameramen and turned into a 30-minute television film which the Army distributed to several hundred commercial television stations. The film promoted the Army's role in what the narrator called "the age of the atom."

Two ex-GIs who now have leukemia say their illnesses are a result of their exposure to low-level radiation 20 years a go at Smokey.

The Public Health Service's Atlanta-based Center for Disease Control(CDC) has recently turned up two addtional ex-servicemen with leukemua who say they, too, were at Smokey." CDC and Pentagon doctors have begun investigating whether the risk of developing leukemia or other cancers was increased among servicemen who participated in Smokey and other nuclear troop tests during the 1950s.

The long-term effects of low-level non-lethal radiation are currently being discussed in the debate over proposed U.S. production of reutron warheads and artillery shells. These would be the first tactical nuclear weapons specifically designed to kill by radiation rather than by blast and heat.

The neutron weapons would also deliver low levels of radiation to civilian areas adjacent to the battlefield. Proponents say this radiation would be relatively harmless compared to blast damage from present nuclear weapons. Those opposed the neutron weapons say the long-term effects of low-level radiation are not known.

In defending the use of troops at Smokey, an Army spokesman said a classified version on the Sixth Army report shows the primary purpose was to test the new Pentomic infantry structure.

A government official who has read the classified report said some portions of the Smokey exercise were legitimate, but termed others "cavalier and some, bizarre."

Of the 1,140 servicemen, most were supposed to watch the shot from trenches 4,500 yards from ground zero.

Seven hours before the shot was to go off, the wind changed and the troops were relocated to a hillside seven to eight miles from ground zero, according to the Army report.

Pual D. Dooper, one of the leukemia victims, has said he believes he was only 3,000 yards from the nuclear device when it exploded. He and other wee knocked off their feet by the blast, he recalls.

Some 45 minutes after the explosion - which was almost three times more powerful than the 1945 Hiroshima bomb - 18 soldiers called "pathfinders" landed in helicopters "in the objective area," according to the report.

A Pentagon spokesman said he did not know exactly how far that was from fround zero but thought it one to three miles.

The bomb was exploded from a 700-foot tower to limit fallout. But the burst disintergrated the tower itself into radioactive metallic dust.

The first of the main troop-carrying helicopters landed in the maneuver area about 90 minutes after the shot.

The initial objectives "were seized," according to the report on the mock invasion, about two hours after the blast.

The initial objectives "were seized," according to the report on the mock invasion, about two hours after the blast.

The initial objective, according to a pentagon spokesman, was supposed to be "fortifications" about one mile from ground zero. The spokesman, however, could not say whether those were the ones actually taken.

Somkey continued for another hour and a half. Then, according to the report, the troop advance was halted because radiation safety teams said a danger point had been reached. That radiation level is still considered classified, a Pentagon spokesman said yesterday.

In the course of the advance, the troops, according to Cooper, had kicked up a lot of dust and he and others did some crawling.%TThe men wore film badges to record radiation exposure. But the badges, Pentagon and other government officials said, did non pick up radiation from fallout on the ground or any radioactive dust inhaled.

tr add 5

The Pentagon spokesman said Cooper's film badge showed he had received only 1.25 rads, while others in his company got almost 2 rads.

Although sciestists and doctors agree that there is a connection between radiation and leukemia, there is no agreement on whether low-level radiation can cause the illness years affter the exposure.

The CDC doctors are attempting to obtain the names of all the Smokey participants to follow up on their present health.