The long-overlooked medical evidence from the case of Joseph Harding suggests that for some workers radiation doses at the Paducah Gaseous Diffusion Plant were far higher than previously believed, and may have been dozens of times above federal limits, according to one analysis of the data.

The hazards for uranium workers are further underscored by unpublished research from a sister plant in Tennessee. A draft study of workers at the K-25 plant in Oak Ridge shows unusually high death rates for former uranium workers, as well as sharply higher rates of lung and bone cancers.

The results of Harding's posthumous tests, conducted as part of a lawsuit in 1983 but never published, offer the strongest corroboration to date of hazardous conditions inside the Paducah plantstrongest corroboration to date of hazardous conditions inside the uranium , where workers labored for decades in a haze of radioactive dust that was sometimes laced with deadly plutonium.

"Uranium content of the bone was far in excess of normal expectations," wrote Alice Stewart, an internationally known British researcher who reviewed the results of laboratory tests of Harding's remains for his estate. "The terminal finding overrules all earlier impressions [from U.S. government officials] of NO internal depositions of uranium."

Lab technicians were unaware of the presence of plutonium at the plant and did not test for it. Plutonium is about 100,000 times more radioactive per gram than uranium and can cause cancer if inhaled in microscopic amounts. Workers only recently learned that plutonium and other highly radioactive metals entered the plant in contaminated uranium shipments from the early 1950s to the mid-1970s.

The Department of Energy has launched an extensive investigation into claims of worker exposures at the Paducah plant as well as the K-25 plant and a third facility in Ohio. While the department had not evaluated the results of Harding's bone tests as of last week, agency officials said it is now clear that uranium workers were not properly protected until at least 1990, when new safety guidelines were implemented.

"This reaffirms our decision to get out of the business of fighting sick workers," David Michaels, assistant secretary for environment, safety and health, said in an interview Friday. "This case is an example of how the DOE placed mission and secrecy in a paramount position in the past. Right now, we should be bending over backward to help those workers who helped win the Cold War for us."

Both the Paducah and K-25 plants were owned by the federal government and operated by the same group of corporate contractors: Union Carbide from the 1950s to the early 1980s, followed by Martin Marietta and Lockheed Martin Corp.

The latter two are the targets of a lawsuit filed by a group of current employees who allege unsafe working conditions and environmental contamination. Former workers also have alleged that radiation monitoring equipment at the Paducah plant was defective; in some cases, they say, "film" badges used to monitor exposures contained no film.

"The dose evidence corroborates our allegations that the health physics program at Paducah has been essentially nonexistent," said Thomas Cochran, nuclear program director at the Natural Resources Defense Council, which joined workers in the lawsuit. "The contractors have been operating in callous disregard for the health and safety of the work force."

Harding, an 18-year veteran plant worker who died of cancer in 1980, was hailed last week by Energy Secretary Bill Richardson as a "hero of the Cold War." But for the nine years before his death his claims of radiation exposure were vigorously challenged by contractors and Energy Department officials, who said conditions in the plant were safe.

The department disputed Harding's allegations – verified years later by other workers – of a dense fog of uranium dust and smoke that would cling to workers' skin and coat their throats and teeth. A department study in 1981 attributed Harding's death to a combination of smoking and eating country ham.

Eventually Harding developed stomach cancer along with an array of unusual maladies that are sometimes linked to radiation exposure, including perforations in his lungs and strange fingernail-like growths on his palms, wrists and shoulders. But after being discharged from the plant in 1971, Harding was denied a disability pension and lost his medical insurance. His widow's efforts to reclaim the pension were opposed by lawyers for Union Carbide and the Energy Department, and she eventually settled her claim for $12,000.

The exhumation of Harding's remains in 1983 was a final attempt by Harding's widow to verify his assertions of exposure to radioactive uranium dust in the plant. His bones were analyzed by a Canadian lab for uranium, but for reasons now unclear the results were never published.

The lab report – obtained last week by The Post – not only supported Harding's claims of radiation exposure but also suggested hazards at the plant were far greater than previously believed: More than a dozen years after Harding left the plant, his body contained uranium at levels up to 133 times higher than is normally found in bones.

Moreover, the type of uranium found was "not from natural sources," and apparently came from the plant's uranium enrichment process, the report said.

Because uranium is slowly purged by the body over time, the levels in Harding's bones would have been "several-fold higher" during the time he was employed, the lab report stated.

Exactly how much higher is unclear. But Carl Johnson, a Colorado physician and radiation consultant who analyzed the test results for Harding's widow in 1983, said Harding's uranium "bone burden" in the 1970s would have been between 1,700 and 34,000 times higher than normal. Based on those levels, the annual radiation dose to Harding's bone tissue would have been 30 to 600 rems a year. Under current standards, U.S. nuclear industry workers are allowed a maximum full-body dose of 5 rems a year.

Radiation experts who reviewed the data for The Post said the results could have been skewed by a number of factors, including the possible presence of plutonium in Harding's bone tissue. But by any measure, the exposure was certainly high.

Arjun Makhijani, president of the Institute for Energy and Environmental Research, said conditions at Paducah appear to have been similar to an Energy Department site at Fernald, Ohio, where concentrations of radioactive particles in the air are now known to have far exceeded then-allowable limits, in one instance by 97,000 times.

"The DOE and its contractor Union Carbide committed a gross injustice on Joe Harding," Makhijani said. "The DOE is perpetuating that injustice upon the half-million people who worked in the nuclear weapons complex since it has not yet provided the vast majority of the survivors among them with medical monitoring and medical help."

Energy Department officials are now pledging increased medical tests and possibly compensation to thousands of men and women who were exposed to chemical and radiological hazards at Paducah and other facilities in the U.S. nuclear weapons complex. The department's investigative team at Paducah in coming weeks will attempt to determine exactly what the hazards were, and who was exposed.

The task is fraught with obstacles, including a dearth of monitoring data from the early years when radiation exposures were likely to be highest. Unlike the K-25 plant, no comprehensive study of worker histories has been attempted at Paducah.

The draft study of uranium workers at the K-25 plant appears to offer further support for concerns about hazards inside such facilities. The mortality study of about 11,000 former workers at the plant was conducted by the Oak Ridge Institute for Science and Education. Although the research essentially was completed in 1994, funding for the study was dropped before it could be peer reviewed and published in a scientific journal.

The draft report, obtained by The Post, shows higher rates of death for all causes among former workers, a finding that is significant in itself, given that government workers are typically healthier than the general population because of higher salaries and access to health care.

The study also shows higher rates of cancers of the lung (19 percent) and bone (82 percent) among white male workers compared with the general population. Both cancers are sometimes linked to radiation exposure.

Researchers point to several factors that could have skewed the results, including the inclusion in the survey of a sample of thousands of people who worked at the K-25 plant for a relatively brief period during World War II.

Since many able-bodied men were in the military during that period, the remaining work force may have been less healthy than the general population, the authors said.

A new study is underway to track death rates among K-25 workers who were exposed to the highest amounts of radiation. Similar mortality studies at the Portsmouth Gaseous Diffusion Plant in Ohio have shown relatively low rates of cancer.

Another possible problem in evaluating risks for Paducah workers is the reliability of the data. Previous Energy Department audits of the plant's safety records cited extensive problems with monitoring programs and equipment. And former and current workers at the plant say they believe radiation monitoring was shoddy in the past.

Al Puckett, a retired union shop steward who worked at the gaseous diffusion plant in the 1960s and 1970s, said workers would sometimes open their "film" badges only to find no film inside. Suspecting that no one ever examined workers' radiation monitors, Puckett and his colleagues sometimes exposed the badges to radiation by leaving them for hours on top of barrels of enriched uranium.

"We turned the badges in and that was the last we heard of it," he said. "No one ever said anything to us."