March 21, 2023 – Amy Lindberg, a 63-year-old retired Navy captain, began experiencing some troubling symptoms 6 years ago.
“I had anxiety, depression and cognitive issues – 'brain fog' – and it didn't add up for me,” she said. “I have a thyroid problem and was going through menopause, but this didn't seem like my usual thyroid or menopause issues.”
Lindberg consulted a neuropsychologist and was diagnosed with mild cognitive impairment and major depressive disorder.
“But while he was examining me, he asked me questions that I found strange for a psychologist. He wanted to know if I had any problems with my sense of smell. He wanted to see how my arm swung.”
Lindberg, who also had a resting tremor in her right hand, did indeed have some problems along with her sense of smell and a really limited arm swing. The psychologist referred her to a neurologist, who diagnosed her with Parkinson's disease.
The causes of Lindberg's illness likely lie in a 4-year period of exposure to trichloroethylene (TCE), a typical chemical present in gun cleaners, cleansing products, and lots of other business products. According to to a new paper According to a world team of scientists, TCE could also be related to an increased risk of Parkinson's disease by as much as 500 percent.
When Lindberg was in her twenties, she was stationed at Camp Lejeune, a naval base in North Carolina. “I was there between 1984 and 1988 and, without knowing it, I drank, cooked and swam in contaminated water.” It has since been revealed that the water at Camp Lejeune was contaminated with TCE.
Lindberg is one in all seven people whose stories are told within the researchers' study, which also includes a radical review of previous studies in animals and humans. Taken together, the information suggest a disturbing link between TCE exposure and the event of Parkinson's disease, often many years later.
Unknown exposure
TCE was developed in a laboratory in 1864 and business production began in 1920, the authors write.
“Due to its unique properties, TCE is used in countless industrial, commercial, military and medical applications,” including refrigeration, cleansing electronics and degreasing engine parts. Until the Seventies, it was even used to decaffeinate coffee. In the past, it was utilized in dry cleansing, although today the same chemical, perchloroethylene (PCE), is used as an alternative.
TCE use peaked within the Seventies, when it was “ubiquitous,” because the authors put it. About 10 million Americans worked with it or similar chemicals. Although the numbers are lower today, a big variety of Americans still come into contact with this toxic chemical every day.
Exposure to TCE shouldn't be limited to those that work with it, because it also pollutes outdoor air, groundwater and indoor air. It contaminates as much as a 3rd of U.S. drinking water and is found at half of the 1,300 most toxic Superfund sites which can be a part of a federal cleanup program, including 15 in California's Silicon Valley, where TCE was used to scrub electronics.
Although the military has stopped using TCE, the chemical has been found on quite a few military bases, including Camp Lejeune. From the Fifties through the Nineteen Eighties, 1 million Marines, their families, and civilians who worked or lived on base were exposed to TCE and PCE concentrations in drinking water as much as 280 times higher than levels considered protected.
“Exposure can be occupational or environmental and is often largely unknown at the time of occurrence,” said the lead creator of the scientific paper, Dr. Ray Dorsey, a professor of neurology on the University of Rochester in New York, in an interview.
“Fastest growing brain disease”
Dorsey calls Parkinson's “the fastest-growing brain disease in the world.” He said genetic aspects alone (which affect only about 15% of Parkinson's patients) cannot explain the rapid increase in latest diagnoses. Nor can age alone explain it.
“Certain pesticides … are likely causes, but they would not explain the high prevalence of Parkinson's in urban areas, as is the case in the United States,” he said. Rather, other aspects are involved, and “TCE is probably one of those factors,” Dorsey said. But despite the widespread contamination and frequency of use of the chemical, the link between TCE and Parkinson's has been little studied, he said.
To fill this gap, Dorsey and his colleagues took a detailed have a look at studies specializing in the possible link between TCE and Parkinson's and presented seven cases to reveal the connection.
They reviewed studies from 50 years ago, when the link between TCE and Parkinson's was first suspected. Since then, studies in mice and rats have shown that TCE in high doses easily penetrates the brain and body tissues.
One of The authors examined human studies compared the danger of Parkinson's disease in twins where one twin was exposed to TCE and the opposite was not. The researchers found that the twins exposed to TCE had a 500% increased risk of Parkinson's disease.
“TCE damages the energy-producing parts of cells, the mitochondria,” Dorsey said. The nerve cells which can be particularly sensitive to TCE's toxins are people who produce dopamine, a brain chemical that's less present in Parkinson's patients. “That may partly explain the connection.”
Public health options
All seven people whose stories are told either grew up in or hung out in a region where they were exposed to TCE, PCE or similar chemicals, or were exposed to them at work.
The authors admit that the role of TCE in Parkinson's is “far from clear.” Exposure to TCE is usually related to exposure to other toxins or unidentified genetic risk aspects.
However, they indicate that Parkinson's shouldn't be the one health problem linked to TCE. The chemical has been linked to miscarriages, many kinds of cancer, neural tube defects and quite a few other conditions.
“Over the generations, countless people have died from cancer and other diseases associated with TCE. [and] Parkinson's could be the newest disease,” Dorsey said. “Banning these chemicals, containing contaminated sites and protecting at-risk homes, schools and buildings could create a world where Parkinson's becomes increasingly rare and out of the ordinary.”
For example, indoor air pollution can be improved through vapor remediation. And while efforts are currently underway to clean and contain contaminated sites, these efforts should be accelerated. The authors also recommend more research to understand how TCE contributes to all diseases.
Lobbying
Brian Grant is one of the people mentioned in the newspaper. Grant was once a successful NBA player who played in the league for 12 years. At the age of 34, he developed symptoms of Parkinson's disease and retired from basketball. Two years later, he received the official diagnosis.
Grant is glad that researchers are shining a spotlight on the role of TCE and similar chemicals in Parkinson's because he was first exposed to it at age 3 when his father, then a Marine, was stationed at Camp Lejeune. His father later died of esophageal cancer, a disease that has been shown to be linked to TCE.
“I know firsthand how difficult it is to live with Parkinson's,” Grant said. “I've seen the impact the disease has on families and communities.” And Grant worries that his children and grandchildren could get the disease, too.
“When I learned from Dr. Dorsey about the research linking chemicals like TCE to PD, I think it's important because we can do something about it. We can do things to prevent future generations from getting this disease,” Grant said.
He founded a foundation to “enable people affected by Parkinson’s to lead active and fulfilling lives.”
Lindberg also volunteers to assist veterans apply for disability and medical health insurance advantages, which the Veterans Administration provides to soldiers stationed at Camp Lejeune between 1953 and 1987. Parkinson's is taken into account a “presumptive condition” on a disability rating scale that qualifies for these benefits.
She also worries about the impact of the contaminated water on her children, especially since she was pregnant during her years at Camp Lejeune. Like Grant, she wants to make the world a better place for people with Parkinson's.
“I'm an advocate for the disease on the local, state and national levels,” she said. “I would like to enhance the standard of life for individuals with Parkinson's and stop the rapid spread of this disease.”