Fallout Hazards Believed Less Than Many Suspected

For more than 20 years scientists have been asking whether radioactive fallout from nuclear weapons tests in Nevada in the 1950s caused deaths from cancer among people living downwind.

Now, medical researchers may finally be nearing a definitive answer: possibly, but if so, probably not many.

Lingering questions about fallout have taken on fresh urgency in recent weeks amid controversy over the safety of the government’s aging complex of nuclear weapons production facilities. A three-year investigation by the Energy Department has found endemic problems of lax management, antiquated equipment and alarming releases of radioactive materials.

The government is only beginning to assess the long-term consequences of radioactive emissions from several of its weapons plants, particularly the huge plutonium production facility at Hanford, Wash. But a large and growing body of evidence, most recently from long-term studies of the Nevada test fallout, suggests that the hazards may be less than many fear.

An exhaustive, six-year study financed by the National Cancer Institute in Utah, the state that received the heaviest dusting of radioactive fallout from nuclear weapons tests in Nevada in the 1950s and early 1960s, has found no indication thus far of the dramatic increase in leukemia or thyroid cancer that many had feared.

“There is not a marked effect,” said Dr. Walter Stevens, the interim dean of the University of Utah School of Medicine. “There is nothing that leaps out and says, ‘Wow, look at this.’ ”

Stevens and his colleagues note that computer analysis of their findings is still under way. They say their $7-million study may yet yield evidence that fallout has caused a small number of thyroid cancers and leukemia deaths since the 1950s.

But Stevens noted that “any large-scale effect should be apparent by now. . . . In fact, I don’t see a major hazard. I don’t see anything I would be overly worried about.”

He and other scientists acknowledge, however, that such reassurances are unlikely to allay popular fears of a threat that cannot be seen, felt, smelled or tasted--and, worse yet, may have been inflicted by the government.

“No matter what we find,” Stevens said, “there will always be those who don’t believe us.”

Study Held Meticulous

Many authorities consider the Utah study to be the most meticulous and sophisticated attempt yet made to answer--if only in part--an intensely emotional question that has ebbed and flowed for decades: Has the nation’s 45-year effort to build and maintain nuclear weapons sacrificed some of the same citizens the weapons were meant to protect?

Time and again, popular fear and moral outrage have risen on the strength of new studies that suggest high levels of cancer in Utah children dusted by fallout, in soldiers exposed to atomic tests or among workers in weapons production plants.

Each time, however, closer scrutiny has shown the most alarming studies to be statistically flawed, ambiguous or distorted by random fluctuations in the mortality rates of the groups under study.

“There is a lot of emotion caught up in this question, a lot of feeling of people versus the government,” said Bruce Wachholz, a radiation health specialist at the National Cancer Institute who has supervised the University of Utah study.

The current controversy has grown partly out of large volumes of information the Energy Department has released over the past two years on safety problems at its weapons production facilities.

Prominent among the system’s critics has been Energy Secretary John S. Herrington, who is pressing Congress to spend up to $150 billion over the next 40 years both to modernize the government’s 14 major production plants in 10 states and to permanently dispose of millions of gallons of highly radioactive military wastes accumulated since 1945.

3 Reactors Closed

In South Carolina, all three of the government’s operable production reactors are shut down for safety improvements, threatening an eventual shortage of tritium, an isotope of hydrogen that is the perishable fuel of thermonuclear weapons.

In Colorado, safety hazards and the contamination of three workers with small amounts of plutonium have forced the partial shutdown of the government’s Rocky Flats processing plant near Denver.

In Idaho, Gov. Cecil D. Andrus is blocking shipments of radioactive wastes from Rocky Flats to a temporary storage site in his state.

And in Ohio, Gov. Richard F. Celeste has called on the Energy Department to close its uranium processing plant at Fernald. Ohio environmental officials estimate that 350 tons of uranium compounds, probably more toxic than radioactive, have leaked from the Fernald facility over the past 30 years. Hundreds of local residents, blaming the contamination for cancer and other diseases, have been trying to sue the government’s former contractor, NLO Inc., which is seeking refuge under the government’s broad immunity from suit.

But the most worrisome revelations stem from the government’s first and largest plutonium production reactors at Hanford, Wash., a 570-square-mile reservation on the Columbia River built amid the wartime urgency of the Manhattan Project. It was Hanford that produced the baseball-sized lumps of plutonium that fueled the first nuclear explosion at Alamagordo, N.M., in July, 1945, and a month later obliterated Nagasaki.

Some 19,000 pages of documents released by the Energy Department in 1986 show that between 1944 and 1953, in an age when the potential hazards were still only dimly perceived, Hanford’s operators released 530,000 curies of radioactive Iodine-131, a waste product that disappears by half every eight days.

Raises Cancer Fears

Of this amount, 350,000 curies were released in 1945, during the crash effort to build the first atomic weapons and years before scientists realized that airborne iodine could work its way from grass through cows and milk to the human thyroid gland. Now, it has raised fears of thyroid cancer in nearby communities.

Under pressure from local environmental groups, the Energy Department and the federal Centers for Disease Control in Atlanta have launched two related studies of Hanford’s radioactive iodine emissions that are expected to cost a total of $20 million over the next four to five years.

Some health officials have questioned the usefulness of such retrospective studies. “Who is this going to help?” asked Dr. Samuel Milham Jr., a Washington state epidemiologist who, in response to persistent public fears of a cancer epidemic around Hanford, has looked twice for statistical evidence in recent years and found none.

“From the standpoint of emissions, everyone agrees Hanford has long since cleaned up its act,” Milham noted. “The only ones you end up helping are the lawyers and their litigants.”

Others, among them the CDC’s Daniel Hoffman, who will supervise the agency’s Hanford study, argue that if there are people at risk, they deserve to know who they are, particularly because nearly all thyroid cancers are surgically curable.

Glenn Accuses Government

Amid a rising tide of public outrage at the disclosures, Sen. John Glenn (D-Ohio) has accused the government of “poisoning our people in the name of national security.”

Physicians for Social Responsibility, an anti-nuclear group that shared the 1985 Nobel Peace Prize with an official Soviet counterpart, spoke of a “national public health emergency” and described Hanford as a “creeping Chernobyl . . . slowly and steadily affecting the health and lives of millions.”

Several independent experts, however, say comparisons with the Soviet nuclear accident in 1986, which released 50 million curies of radioactive wastes in a span of only 10 days, are greatly overdrawn.

“That’s an extremely unfortunate comparison to make,” said John Till, who heads an independent panel directing the Energy Department’s study of radiation releases at Hanford. “To compare two sources when the environment is different is very irresponsible.”

What is more, the past 40 years of research on the health effects of environmental radiation suggest that such flamboyant alarms will be hard to prove.

Since 1902, when cancer was first linked to X-ray exposure, the federal government had spent more than $2 billion trying to define and clarify the health risks of radiation, according to a 1981 tally by the congressional General Accounting Office.

Papers Yield Data

While the GAO acknowledged that the resulting 40,000 scientific papers had “yielded a tremendous body of useful data,” it concluded that “the inherent limitations on these types of studies make it highly unlikely that any reliable conclusions will be reached.”

One reason is that in most industrialized societies, one in four people can expect to die from cancer in any case. Most studies of known radiation exposures in large populations suggest that they add only a thin, almost indiscernible increment to this toll. Using the still-rough tools available to doctors and statisticians to gauge such effects “is like trying to measure the thickness of a piece of paper with a yardstick,” said Bob Alvarez, a nuclear specialist with the Environmental Policy Institute in Washington.

Nearly 45 years after the dawn of the nuclear age, the firmest measure of the cancer risk from radiation remains the intensively studied atomic bomb survivors of Hiroshima and Nagasaki. Among the original 109,000 survivors selected for study, the number of “excess” cancer deaths attributed to radiation currently stands at about 480.

Efforts to study radiation exposures in smaller groups has sometimes led to maddening confusion. The 200,000 U.S. troops who took part in military exercises at nuclear tests in Nevada and the South Pacific in the 1950s and early ‘60s, often at a range of a few miles from ground zero, provide a case in point.

In 1977, news reports of a veteran who attributed his leukemia to radiation at the Smoky nuclear test in Nevada 20 years earlier led to a public outcry, demands for compensation for veterans of the tests--and the inevitable studies. Two years later, the CDC reported eight leukemia cases among the 3,554 troops at the Smoky test, more than double the 3.5 statistically expected.

Six years later, in May, 1985, the National Academy of Sciences finished a much larger but little-noticed study of deaths among 46,186 troops who took part in one or more of five nuclear test series. Although it confirmed the CDC’s Smoky findings, the academy said they now seemed to reflect a unique, probably chance fluctuation in mortality rates. Troops exposed to other nuclear tests showed no rise in leukemia or other cancers, and some groups actually showed slightly lower rates than expected.

“We found nothing,” said an academy scientist who took part in the study. “Evidently we gave Congress the wrong answer, or one that was unacceptable.” In 1987, Congress adopted a special benefits program for veterans of nuclear tests who contract one of 10 forms of cancer.

Efforts to look for increased cancer among tens of thousands of workers in nuclear weapons production plants have proved even more bewildering. These studies are complicated by worker exposure to organic chemicals whose effects can mimic those of low-level radiation.

Review Disputes Findings

In 1977, for example, a 13-year study of about 4,000 deaths among 30,000 former workers at the Hanford plant seemed to reveal an incidence of cancer 10 times the expected rate. By 1981, a review of the study commissioned by the GAO concluded that at most it demonstrated only one additional cancer death, and even that was in doubt.

The story at the Rocky Flats plutonium plant near Denver, where workers are exposed both to low-level radiation and exotic chemicals, seems much the same. Half of the studies of cancer among Rocky Flats workers and nearby residents suggest a worrisome increase, according to Kenneth Lichtenstein, a physician appointed by Gov. Roy Romer to an environmental committee monitoring the plant.

“The other half refute them,” noted Lichtenstein, who is a director of Physicians for Social Responsibility.

No facet of the long-running debate over radiation and health has proved more contentious than the question of whether radioactive fallout from the Nevada tests led to increased cancer downwind, especially among children in southern Utah, who were considered at greatest risk of thyroid cancer from radioactive iodine.

In the mid-1960s, the U.S. Public Service surveyed 5,000 children in Utah and, for purposes of comparison, in Arizona, where relatively little fallout landed. The Public Health Service investigators found no evidence of increased thyroid cancer, and in fact almost no thyroid cancer at all. But because radiation-induced cancer usually develops slowly, critics said they might have looked too soon.

Finds Leukemia Deaths

Then in 1979, a statewide study of death certificates by a University of Utah researcher, Joseph L. Lyon, found 19 more leukemia deaths in southern Utah than normal mortality rates appeared to predict--suggesting more than a doubling of leukemia in an area where fallout was heaviest.

By 1984, however, researchers at the National Cancer Institute said they were unable to duplicate Lyon’s findings, and concluded that they revealed more about the pitfalls of fiendishly complex statistical analysis than about the health of children in Utah.

Now, four years later, the NCI’s Charles Land, who led the critique of Lyon’s work, believes still further research may have found a small “cluster” of leukemia cases around St. George, Utah, the town hardest hit by wind-borne fallout in the 1950s.

In hope of settling the question once and for all, researchers at the University of Utah medical school set out in 1982 to track down and review the medical histories of all 1,177 leukemia cases reported in Utah since 1952, as well as the histories of another 5,600 healthy “control” subjects. In addition, the Utah researchers have reexamined about 2,800 of the 5,000 children surveyed by the Public Health Service nearly 20 years before.

This time, moreover, the researchers have tried to estimate the radiation dose actually absorbed from fallout by each of the nearly 10,000 people encompassed by the six-year project. They hope to determine whether any increase in cancer that may be observed can actually be tied to radiation and, if so, how a given dose affects the future risk of cancer.

“This was not as difficult as it sounds,” study director Stevens noted. Since 1979 the Energy Department has reconstructed and published detailed maps of fallout patterns. At the same time, however, because radioctive iodine disappears quickly from the environment, researchers had to study dairy management practices and family dietary patterns in Utah in the 1940s and ‘50s to estimate how much actually reached consumers.

“How long did it take milk to reach consumers? How much milk were people drinking?” asked the NCI’s Wachholz. “You rely on peoples’ memories. But who really remembers how many glasses of milk they drank a day when they were 4 years old?”

Draft Report Due

A draft report of the Utah study is due at NCI next month, but the agency does not currently plan to publish its results until a final report is ready sometime next spring.

Meanwhile, Stevens said, the findings suggest that public fears of an epidemic of cancer around Hanford and other weapons production plants are probably exaggerated.

“Of course people have a right to be concerned,” he says. “But based on what we have learned, the degree is probably more than it should be.”