Study Links Lung Cancer Deaths to Rocket Assembly Jobs
Workers who helped assemble rockets at Rocketdyne’s Santa Susana Field Laboratory died of lung cancer at twice the rate as other employees at the facility, researchers reported Friday.
After a six-year study, researchers at the UCLA School of Public Health released their second and final report examining the cancer risk to employees who worked at the laboratory between 1950 and 1994. The researchers linked the heightened rate of lung cancer to hydrazine compounds, a toxic component used in rocket fuel, although other chemicals may have been involved, they said.
Bladder, kidney, and blood and lymphatic system cancers also claimed twice as many workers who handled a significant amount of hydrazine, the report says, although the authors expressed less confidence in that finding because it is derived from just a handful of cases.
The researchers analyzed medical records of 6,107 Rocketdyne workers employed at the Ventura County lab since it opened in 1949. Over time, dozens of toxic chemicals were used to test and develop rockets and MX nuclear missiles. During the period studied, about 2 million pounds of hydrazine was used at the lab and workers came into direct contact with it through mishaps and workaday exposure, according to the study.
“What you’re seeing is the history of the Cold War and attention paid to production instead of health and safety in that period,” said Dr. John Froines, a UCLA epidemiologist and member of the research team.
But Rocketdyne officials, flanked by company-hired experts at a news conference Friday in Simi Valley where the study results were announced, dismissed the findings as unreliable. Steve Lafflam, division director for safety, health and environmental affairs at Rocketdyne, said the data do not support the findings of elevated cancer risk.
He emphasized that the 500 workers at the lab today continue to deal with very small quantities of hydrazine and use protective equipment when dealing with hazardous chemicals.
“The findings are incomplete, inconclusive and need further work,” said David M. Gute, professor of civil and environmental engineering at Tufts University in Massachusetts, one of seven experts Rocketdyne hired to review the report.
The study joins a growing body of evidence suggesting that work at the lab posed a risk to its employees and possibly the nearby community. Two years ago, the same UCLA team determined in an initial report that workers exposed to radiation during decades of nuclear testing at the lab have an increased risk of dying of cancer. The U.S. Department of Energy paid $1.6 million for the full study and a panel that hired the UCLA team and supervised its work.
The California Cancer Registry, a state agency, in 1997 found that lung cancer was 17% more common in Simi Valley neighborhoods around the lab than in the rest of Ventura, Santa Barbara and San Luis Obispo counties. A similar cancer survey in 1991 showed increased cancer in neighborhoods east of the lab in Los Angeles County. Both those studies, however, appear to have serious flaws.
Community leaders and environmental activists say that taken together, those results provide ammunition to press for a more detailed survey to assess whether pollution from the plant harmed neighbors. Rocketdyne officials said that in the next 90 days they will consider undertaking such a study.
“The workers were the canary and the canary died. We need to know whether we’re safe,” said Marie Mason of Simi Valley, who lives below the hill where the lab is located.
The study released Friday shows that 44 of 1,053 workers at the lab who had heavy contact with hydrazine died of lung cancer. That rate is twice as high as for the workers who had little or no contact with the substance, said Dr. Beate Ritz, a UCLA epidemiologist.
However, it is not certain that all the cancer deaths can be directly ascribed to hydrazine compounds. Hundreds of chemicals were in use at the lab, many capable of causing cancer. The researchers focused on hydrazine because more complete records were available for workers who used it.
Also, the UCLA scientists lacked information showing precisely how much hydrazine each worker was exposed to and for how long. So they instead used job descriptions as a surrogate. Rocketdyne officials faulted the report for failure to fully identify the amounts of hazardous chemicals workers were exposed to.
“While we believe that something is going on with this group of workers, we don’t know for certain what caused the excessive cancer deaths,” Ritz said. “Our best information is that it was hydrazine, but it could be something else related to rocket engine testing.”
The study may underestimate the true risk to workers at the plant, the UCLA scientists said. Their research did not include nonlethal cancer cases and did not attempt to examine other health problems associated with chemicals, including neurological impairment or kidney damage.
“The results they came up with are a minimum. A more comprehensive study would have revealed more damage to the workers,” said Sheldon Plotkin, a member of the board of directors for the Southern California Federation of Scientists and the advisory panel that reviewed the report.
