No Firm Cancer Tie Found by Three Mile Island Study : Radiation: But questions go unanswered as people downwind of the damaged nuclear plant are found to have a slight increase in some diseases.

A major independent review of disease rates around the Three Mile Island nuclear power plant has found no convincing evidence that radioactivity released during the 1979 accident caused any increase in cancer incidence during the six years immediately afterward.

The report did find that people living in the path of the radioactive plume emanating from the damaged plant were slightly more likely to develop lung cancer or a blood cancer called non-Hodgkins lymphoma than were people living nearby in areas away from the plume. But the authors said neither of these diseases is necessarily linked to the accident.

The increases “are curious and we can’t explain it,” said Maureen Hatch, a Columbia University epidemiologist who was the report’s chief author. “It would be hard to make an argument that this is convincing evidence, but it certainly raises questions.”

The study, released Friday, is the largest yet to look at cancer incidence, rather than deaths from cancer, among people living near the plant. Previous studies looked at cancer deaths or at cancer incidence over a shorter period of time.

Many experts say incidence figures give a better measure of cancer risk after exposure to radiation because it can be many more years before stricken people die.

The report appears in this month’s issue of the American Journal of Epidemiology. It was commissioned by the Three Mile Island Public Health Fund, which was established in 1981 as a result of a class-action suit against General Public Utilities Corp., which owns the power plant, and various other companies involved with the plant.

The authors said their study is not definitive because of the small number of cancer cases it describes and because it does not include information about other possible causes of cancer.

Some local citizens and attorneys for people seeking damages from TMI’s owners said they did not think the study was well done, and some charged that the utility company was involved in pressuring the scientists to produce a favorable report.

“It’s as if the tobacco industry was issuing a report on whether cigarettes are good for you,” said Arnold Levin, a Philadelphia lawyer who represents several people seeking personal damages from the utility company.

The study focused on leukemias and childhood cancer, which Hatch said are the types of cancer most likely to occur after exposure to low doses of radiation. It found that people living in areas that received the most radiation from the plant were no more likely to develop either disease than were people living in areas exposed to the least amount of radiation from the plant.

The incidence of childhood cancer in the heavy radiation areas was 1.06 times that in the low radiation areas, and that of leukemia in people under the age of 24 living in the high exposure area was 2.81 times that of the people in the low exposure area.

But the researchers said these differences were not statistically significant because the total number of cases was very low. Between 1980 and 1985, for example, there were three cases of leukemia for that age group.