THE BOMB STILL KILLS 43 years later, with cancers that consume blood, bones, lungs and breasts. It maims with cataracts, genetic damage and with stunted growth in those who were children.

The first atomic bomb used in war dropped on Hiroshima, Japan, Aug. 6, 1945, and leveled it in a blinding blast of 12,000-degree heat, killing 78,000 people instantly.Scores die each year from the delayed effects.

More than 4,500 names were added during the past year to the list of survivors who died during the past year. Dr. Itsuzo Shigematsu, head of the Radiation Effects Research Foundation, said at least 80 or 90 of those resulted from illnesses directly related to the explosion.

"For these people, and other survivors of the blast, the war has not ended," he said. "They all wonder if and when they'll come down with these diseases as a result of the bombing."

In laboratories on a mountain overlooking the tragically historic city, Shigematsu and nearly 300 colleagues study the effects of nuclear war, trying to add meaning to lives lost or shortened. They also try to comfort the estimated 176,000 survivors.

A similar facility was established in Nagasaki, with nearly 200 employees to examine victims of the second atomic bombing on Aug. 9, 1945. That explosion killed nearly 70,000 people and left about 200,000 survivors.

President Harry Truman established the research facility in 1947 as the Atomic Bomb Casualty Commission. In 1975, it became a joint U.S.-Japanese effort under the new name.

Employees of the Hiroshima center include about 100 "hibakusha," - bomb survivors - who want to learn more about the disaster. It has an annual budget of about $306 million and has conducted life-span studies of more than 120,000 people.

It conducts genetic research to determine the long-term effects of nuclear war and pathological studies in an effort to find causes of death. Doctors visit hospitals and perform two or three autopsies a month at the center.

There is a meditation room for grieving relatives.

The clinic sees an average 40 patients daily, both victims and members of their families. It tests walk-in patients who have come forward more than 40 years later, fearing lingering effects of the bomb.

Test results are given to patients and their doctors. The center does not treat patients because physicians complained of lost business.

Deaths from the bomb's effects have risen dramatically over the years and only recently has the trend shown signs of peaking. Shigematsu said it still is too early to tell whether the number of cancer-related deaths will level off.

He said it is difficult to establish which deaths are bomb-related. Cancer is on the increase generally in Japan and has become the leading cause of death.

Shigematsu said there is no doubt, however, that the risk of death from cancer is greater among those exposed to the bombs: four times higher for leukemia; 1.3 times for lung cancer; 1.5 times greater for bone cancer and 1.6 times for breast cancer.

Instead of the 30 cancer-related deaths a year formerly attributed to the bombing, the Hiroshima center now puts the figure at 80 to 90.

Bomb victims also run significantly higher risks of cataracts, chromosome abnormalities, mental retardation of babies exposed before birth and delayed growth of those who were children in 1945.

Scientists have detected but not been able to prove increased risk of esophageal cancer, colon cancer, urinary cancer, malignant lymphoma and ovary cancer.

They also have found what might be called good news in the context: no increased mortality from diseases other than cancer, no acceleration of aging, no significant increased risk of infertility and no indication so far of increased risk of birth defects among the children of bomb victims.

Children of hibakusha have faced discrimination in hiring and marriage due to fears of greater risk of disease and genetic defects. Shigematsu said the center has helped prove some of the fears unfounded but the figures are far from complete.

"Many of them are just now entering their 40s, where they are at greater risk of contracting cancer," he said. "We will have to wait and see about that."

It is difficult to determine the exact casualties from the bombings of Hiroshima and Nagasaki because the city governments collapsed after the bombings and very few records were kept, he said.

Also, the Japanese government did not take a census until 1950, when it finally asked people who were in Hiroshima and Nagasaki at the time of the bombings to identify themselves. A total of 284,000 people came forward.