EAST HARTFORD, Conn. (AP) -- The incidence of brain cancer at jet engine manufacturer Pratt & Whitney was the same as or less than for the general population, researchers said Thursday.
The researchers, from the University of Pittsburgh and University of Illinois, released the second of three phases of their massive study of 212,513 workers at one of eight Connecticut plants from 1952 to 2001.
Of the workers from that 49-year period who were alive between 1976 and 2004, researchers said they identified 489 cases of malignant central nervous system cancers. Of those, 275 were brain tumors.
Researchers found slightly higher rates of brain cancer at one facility of Pratt & Whitney, a subsidiary of United Technologies Corp. in North Haven, Conn. But they said the difference was not statistically significant and does not appear linked to workplace factors.
The principal researcher, Gary Marsh, said the third and final phase of the study, which is due to be released early next year, will look at whether workplace factors caused cancer.
"Phase 3 is really the definitive step where we can actually link mortality incidence to exposures and characteristics of the work environment," he said at a news conference unveiling the study.
The results mirror the conclusions of the first phase, which were released in September 2008, Pratt & Whitney said.
"We are reassured that the study does not show an increased rate of brain cancer among our Connecticut employees," the company said in a statement.
The company commissioned the $12 million study, which is being overseen by the Connecticut Department of Public Health, in 2002 after complaints from families of workers who died from a form of brain cancer.
The widow of one worker is dissatisfied with the study, which she said is showing the company didn't do anything wrong. Shirley Platt, whose husband, Francis Platt, died of brain cancer in 2004 at age 73, said the third and definitive phase should have been released immediately.
Platt, who also worked at the company until she retired in the mid-1990s, said brain cancer continues to afflict Pratt & Whitney employees.
"There's still something out there that needs studying," she said.
Concerns were initially raised in 2000 by a health committee of representatives of Pratt & Whitney and the International Association of Machinists, which represents the workers. The widows of two Pratt & Whitney employees were among the first to push for a comprehensive study.
One of the women was Carol Shea, whose husband, John Shea, died of brain cancer in 2000 at age 56. He worked at the North Haven plant for 35 years.
Shea said before the release of the results Thursday that she does not expect to hear anything substantive until the third phase is wrapped up.
"Until it's done, how will they know?" she asked. "Right now, what can we do? All we can do is wait. We can't do anything until the study is done."