Higher Cancer Rate Found for Some at Lab
Workers who helped assemble rockets at Rocketdyne’s Santa Susana Field Laboratory died from lung cancer at twice the rate of other workers at the facility, researchers reported Friday.
After a six-year study, researchers at UCLA’s 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 cancers in people to three hydrazine compounds, toxic components used in rocket fuel, although other chemicals may also be 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 concludes, although the authors expressed less confidence in those findings because they derive 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, MX nuclear missiles and satellites that seek and destroy other satellites. 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 a 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 study’s findings of elevated cancer risk are not supported by the data. 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.
Indeed, the UCLA researchers candidly pointed out shortcomings they were unable to surmount, but stood behind the study’s key findings as fundamentally sound.
For example, the scientists lacked information showing to just how much hydrazine workers were exposed. Rocketdyne’s experts said that absent the correct dosage, it is difficult to know an individual’s exposure to a toxin, and hence, the actual health risk.
Instead, the UCLA team relied on job descriptions, which showed how frequently workers came into contact with hydrazine. However, they acknowledge other chemicals were present in those jobs, so it is possible that substances other than hydrazine may have contributed to cancer deaths.
“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,” said Dr. Beate Ritz, a UCLA epidemiologist. “Our best information is that it was hydrazine, but it could be something else related to rocket-engine testing. We know that there is an excessive number of cancer deaths among workers in the high-exposure hydrazine group.”
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However, the study may underestimate the true risk to workers at the plant, the UCLA scientists said. Their research did not include nonlethal cancers and did not attempt to examine other health effects, including neurological impairment, harm to the respiratory system or liver and kidney damage associated with toxic chemicals.
And the researchers concentrated almost exclusively on hydrazine, rather than the dozens of other chemicals used at the facility. They said they did so to make the study more manageable and because they had access to more complete records for workers who used hydrazine. Few studies, too, have been done on health effects on workers from the substance.
“The results they came up with are a minimum,” said Sheldon Plotkin, a member of the board of directors for the Southern California Federation of Scientists and of an advisory panel that state lawmakers established to supervise the UCLA researchers. “A more comprehensive study would have revealed more damage to the workers. What they came up with underestimates the amount of risk.”
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A companion study of 4,000 workers at the lab did show that workers who had frequent contact with asbestos did not experience more cancer deaths than employees who had little contact with the substance, which is commonly used in insulation.
The first phase of the study by the UCLA team examined how exposure to radioactive materials once used at the Rocketdyne lab affected past and current employees. That study, completed in September 1997, showed that workers exposed to radiation during decades of nuclear testing at the lab have an increased risk of dying of cancer. Specifically, the study found increased prevalence of cancers typically associated with radiation, including leukemias, lymphomas and lung cancer. Other increased cancers include those of the stomach, bladder, mouth and throat.
The report released Friday showed that 404 workers at the lab died of all cancers during the study period. Of those, 44 deaths due to lung cancer occurred among 1,053 workers at the lab who had routine contact with hydrazine. That rate is twice as high as the rate for the workers who had little or no contact with the substance, said Ritz, of UCLA.
Deaths from cancers of the bladder, kidneys and of the blood and lymphatic system were also twice as common in the workers who worked extensively with hydrazine compared to those that didn’t. However, so few of those cancers occurred that researchers were hesitant to place too much credence in that conclusion, explained Hal Morgenstern, a UCLA epidemiologist and principal author of the report.
The risk of dying from one of those cancers was highest among those who worked in the high-exposure jobs during the 1960s, when use of hydrazine was at its peak, the study shows.
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Hydrazine, an oily, fuming liquid with a fishy smell, is used in rocket fuel and produces poisonous gases when burned. It was first put into wide use as a propellant for rocket-powered Luftwaffe fighter planes in World War II and has since been used to make everything from spandex to pharmaceuticals to photographs.
Hydrazine is highly toxic and readily absorbed through the skin, throat and lungs. Repeated low doses can cause blood disorders, liver and lung damage, seizures, blindness and injury to the central nervous system. Hydrazine is known to cause cancer in animals and the International Agency for Research on Cancer classifies the substance as a possible human carcinogen.
The latest health study joins a growing body of evidence suggesting work at the lab endangered its employees and possibly the nearby community.
Preliminary findings from a 1997 California Cancer Registry report that surfaced Thursday showed lung cancers were 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 to the east of the lab, prompting some state legislators to demand funds for an independent health study, a task awarded to UCLA. The U.S. Department of Energy paid $1.6 million for the research and a panel to oversee work done by the UCLA scientists.
Results from all those studies provide community leaders and environmental activists with ammunition to press for a more detailed survey to assess if pollution from the plant harmed people living nearby. Lafflam at Rocketdyne said that in the next 90 days the company 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.
