HARTFORD, Conn. (AP) -- For jet engine maker Pratt & Whitney, a long-simmering dispute over worker illnesses was settled by a massive 11-year study that found no elevated risk of brain cancer at its plants. But for dead workers' relatives who first raised concerns years ago, the matter is far from closed.
Their next step hasn't been decided, and the choices are limited. Matt Shafner, a New London lawyer who represents families, said more than 90 workers' compensation claims have been filed. But he won't move forward until an independent review of the study is completed, he said.
"It's not over," said Carol Shea, whose husband, John Shea, worked at Pratt & Whitney's North Haven plant for 35 years and died of brain cancer in 2000 at age 56.
Some relatives of workers who died of brain cancer a decade or more ago are dissatisfied with the study, saying it failed to prove that the deaths of their loved ones were part of a broader problem.
Todd Atcherson, whose father, Charles Atcherson, died in 1998 after working at Pratt & Whitney for about 25 years, said the enormous scope of the study — health and work records of more than 200,000 employees were reviewed — fail to explain the deaths of his father and a small group of other workers at the North Haven plant.
"They skewed out the numbers so far, they lost focus of five people who worked in the same site and all died," he said.
Shea said she believes the researchers are "way off."
"I couldn't believe they couldn't come up with anything," she said.
The study, released last month, was launched "in response to the perception of an unusual occurrence" of glioblastoma, a common and aggressive malignant brain tumor, at the North Haven plant. It found the incidence rates of glioblastoma at the site weren't related to workplace exposures.
The environment at the plant featured a blue haze, a product of aerosol generated from metalworking fluids during fast, hot grinding.
The study, which examined seven other Pratt & Whitney plants in Connecticut, found no statistically significant elevations in the rate of cancer among workers. Researchers at the University of Pittsburgh and University of Illinois at Chicago said they identified 723 workers diagnosed with tumors between 1976 and 2004 at the subsidiary of United Technologies Corp.
The tumors were malignant, benign or unspecified and included 277 cases of brain cancer. Of those, 167 were at Pratt & Whitney's East Hartford site and 57 at North Haven, though North Haven workers were at greater risk of having brain cancer, the study said.
But following a study of the North Haven plant, researchers said they couldn't conclude that the environment or exposures were related to the overall elevations in brain cancer.
Gary Marsh, the University of Pittsburgh researcher who led the study, said that he understands family members' frustrations but that the study is conclusive and definitive.
"Let's face it: Brain cancer is a terrible disease and anyone who suffers from it or had a loved one suffer from it wants to know why they got that disease," he said. "We looked at everything conceivable as a possible cause of brain cancer."
Ray Hernandez, a spokesman for Pratt & Whitney, said the company is satisfied with the study's conclusions and considers the matter closed.
"Since we are confident in the scientific rigor of this comprehensive study, we think it provides the best possible information about this issue," he said in an emailed statement.
The study found no connection between brain cancer and the workplace and researchers found no patterns or trends of other causes of death "suggestive of a workplace relationship," Hernandez said.
In Connecticut, Pratt & Whitney over the years has shut down all but its Middletown and East Hartford plants. Manufacturing processes from decades ago have been transformed and haven't recently raised safety issues.
A few family members said they are wary of the study because it was commissioned by Pratt & Whitney at a cost of $12 million. The university researchers worked independently of Pratt & Whitney and the state Department of Public Health established an advisory group to review the progress, methods and other aspects of the study and address concerns about the study's independence.
John DeLeone, a grinding machine operator at the North Haven plant from 1984 until it closed in 2002, said workers suspected that chemicals specific to that plant were lethal. He criticized the study, which was launched in 2002 in response to concerns about employee deaths at North Haven, for being overly broad rather than focusing on that plant.
"It seemed that only people who got sick were those who transferred from North Haven," he said.
Marsh said the study adds to the body of knowledge of occupational health, used by researchers and relevant to other jet engine manufacturers, such as General Electric Co. and Rolls Royce, he said.
"We concluded there is no evidence of elevated health risks of this population. That's a good thing to know," he said.
But Debra Belancik, the Machinists' union's safety and health representative, said the study "doesn't bring any closure at all."
"All this work we did, all the high rates, all the funerals and wakes I went to, it kind of bothered me a little bit," she said.