Radioactive emissions from a 1959 nuclear accident at a research lab near Simi Valley appear to have been much greater than previously suspected and could have resulted in hundreds of cancers in surrounding communities, according to a study released Thursday.
Chemical contamination from rocket engine testing at the site continues to threaten soil and groundwater in the area around Rocketdyne's Santa Susana Field Laboratory, the study also found.
The nuclear meltdown, which remained virtually unknown to the public until 1979, could have caused between 260 and 1,800 cases of cancer "over a period of many decades," the study concluded.
But the advisory panel that oversaw the five-year study, conducted by an independent team of scientists and health experts, said it could not offer more specifics about potential exposure to carcinogens because the Department of Energy and Rocketdyne's owner, Boeing Co., did not provide key information.
For The Record
Los Angeles Times Saturday October 07, 2006 Home Edition Main News Part A Page 2 National Desk 1 inches; 45 words Type of Material: Correction
Rocketdyne: An article in Friday's Section A about Boeing's Santa Susana Field Laboratory identified Dan Hirsch, co-chairman of a panel overseeing health and environmental studies at the former nuclear testing site, as a physicist. Hirsch is a lecturer on nuclear policy at UC Santa Cruz.
"This lack of candor ... makes characterization of the potential health impacts of past accidents and releases extremely difficult," the panel concluded.
Boeing officials vigorously disputed the findings, saying the study was based on miscalculations and faulty information.
"We disagree entirely with the report's conclusion," said Phil Rutherford, a health, safety and radiation manager for the company. He cited a Boeing-commissioned study released last year that found overall cancer deaths among employees at the field lab and at Canoga Park facilities between 1949 and 1999 were lower than in the general population.
The Boeing report contradicted findings from an earlier UCLA study that found elevated cancer deaths among workers exposed to high levels of radiation.
Critics chided Boeing officials Thursday for failing to provide information for the new study.
"The pattern of secrecy and misrepresentation that began at the time of the accident continues to this day, where sloppy practices are done under a cover of darkness," said Dan Hirsch, a physicist and co-chairman of the advisory panel.
The lab was opened on a craggy plateau in easternmost Ventura County in 1948 as the nearby San Fernando and Simi valleys were on the cusp of a postwar population boom. Originally operated by North American Rockwell, it conducted nuclear research for the federal government for more than four decades before ceasing those operations in the late 1980s. It has also been the site of more than 30,000 rocket engine tests, the thunderous explosions serving as a Cold War-era hallmark for nearby residents.
The 2,850-acre site has been the source of much controversy since the nuclear accident was first widely publicized in 1979. A team of UCLA graduate students obtained documents through the Freedom of Information Act detailing the meltdown.
The disclosure resulted in a number of environmental studies that found widespread radioactive and chemical contamination at the lab. In turn, several investigations into the potential impact on the health of lab workers and area residents were triggered.
The advisory panel was created by local legislators in the early 1990s to oversee some of the studies. Its new report specifically focuses on how the lab's operations, which included decades of rocket engine testing, may have affected the health of people in nearby communities.
The study, paid with federal funding, asserted that the rocket engine tests had caused chemical contamination of water and soil in nearby areas in recent years and "may indicate pathways for other contaminants."
Among the scientists' other key findings:
* As much as 30% of the most worrisome compounds associated with nuclear testing at the lab, iodine-131 and cesium-137, may have been released into the air. But Boeing's Rutherford said data from the site's own airborne monitoring system refutes that claim.
* Unable to obtain weather data from Boeing, scientists made calculations based on varying assumptions about wind speed and direction and estimated the number of potential cancers at 260, with the rare possibility that the number could be as high as 1,800, within 62 square miles surrounding the field lab.
"These cancers, if they occurred, would have been amidst a population of several million people and over a period of many decades," the report said. "The ability of epidemiological studies to identify these cancers, if they exist, in a population that large, is limited, given the uncertainty of where the exposures occurred."
* For years, in violation of restrictions prohibiting such activity, radioactive and chemically contaminated components were disposed of at an open-air sodium burn pit at the field lab, polluting soil and groundwater.
* Perchlorate, a component of rocket fuel, migrated off the lab site, toward populated areas, in surface water runoff. Other contaminants may have spread off site in this manner as well, the report said.