New study links TCE with Parkinson's

Chemical linked to Parkinson's disease
by Sarah Voss, Lexington Herald-Leader

In the late 1970s, Eddie Abney cleaned grease from metal gauges at a Berea factory using a chemical solvent called trichloroethylene, or TCE. The chemical, which is still used today as an industrial degreaser, soaked through his cotton gloves and into his skin. It splattered on his clothes. He breathed in its vapors.

At night, when he came home, he would tell his wife that the smell was killing him.

It may have been.

Researchers at the University of Kentucky have linked industrial use of TCE to Parkinson's disease, which Abney has. It was Abney, 51, who pointed researchers to a possible connection, leading to a study that was published last month in the online version of Annals of Neurology, a journal of the American Neurological Association.

The study shows a clear link between an environmental contaminant and Parkinson's, said Don Gash, the lead researcher.

TCE has been suspected before as a cause of Parkinson's, but the UK study shows a "clear-cut link" from exposure to the chemical to the disease's development, Gash said. "We've connected the dots."

The study found that three people who directly handled TCE at the factory where Abney worked developed Parkinson's disease. An additional 14, who breathed in its vapors, had early symptoms of Parkinson's, but not the disease itself. And 13 more, who were also exposed to vapors, didn't show signs of parkinsonism but had slower fine motor skills than others their age.
As part of the study, researchers gave rats TCE. All of them showed brain damage to the same cells as Parkinson's patients, damage done through the same cellular pathway, the mitochondria. Gash thinks the mitochondria might be the key to finding an effective treatment for Parkinson's.
"We're now focusing our attention on mitochondrial dysfunctions, looking at ways to intervene and promote recovery of mitochondrial functions," Gash said.
The Berea factory where Abney worked is no longer open. It was owned by Dresser Industries, which was sold to Halliburton in 1998. In 2001, Halliburton spun off parts of Dresser Industries, including the Berea factory, into Dresser Inc., a Dallas-based company.
Linda Rutherford, general counsel for Dresser Inc., declined to comment on the UK study, because she had not seen it. She noted that the Berea factory had not used TCE since 2001, when Dresser Inc., took it over.

TCE is a clear liquid, most often used to clean grease from metal. It is found in adhesives, paint removers, typewriter correction fluids and spot removers, according to the Agency for Toxic Substances and Disease Registry, a division of the U.S. Department of Health and Human Services.

TCE does not occur naturally but it is a common contaminant of water, air and soil near factories, military installations and hundreds of waste sites around the country, according to the National Academy of Sciences.

When Abney was diagnosed with Parkinson's in 2001, he and his wife, Susan, wondered whether TCE could have been the cause. Sometimes Parkinson's has a genetic tie, but Eddie Abney didn't have family history of Parkinson's. Environmental factors had been linked to the disease: exposure to certain pesticides or recreational use of MTPT, known commonly as synthetic heroin.

But Abney wondered whether, in his case, it was TCE. He remembered the strong smell of the chemical he had worked with for more than two decades with little protection.
"I had gloves on, but they were just white cotton gloves," Abney said. "If they got wet, they got saturated."

A year after his diagnosis, Abney participated in a clinical drug trial for Parkinson's disease at UK. When he told a researcher his medical history, he mentioned the exposure to TCE, and the fact that others from the factory had Parkinson's. The researcher, Kathyrn Rutland, thought it sounded like a cluster of cases.

"We felt like there was enough there to really get started," said Gash, the lead researcher.
Eddie Abney stopped working in 2001. Parkinson's had made it impossible for him to do his job safely.

These days, he has trouble walking. He can move from room to room with a cane or a walker, but longer distances require a motorized wheel chair. He has trouble talking, and his words slur into one another. He can't swallow well, and his body is stiff.

Susan Abney says she and her husband are glad to know that they weren't wrong, that their hunch about TCE was right. But the knowledge doesn't soothe what has happened to her husband.

"His life is completely different because of this chemical," Susan Abney said. "Nobody told him how dangerous it was. He didn't have the tools or the gloves or the whatever to keep him from getting sick."