A cancer-causing chemical widely used to degrease aviation components and heavy machinery may also be linked to Parkinson’s disease, according to a new research paper that recommends closer examination of areas long contaminated with the compound.
Trichlorethylene, or TCE, is a colorless liquid that has been used to remove gunk from jet engines, strip paint and remove stains from shirts left at dry cleaners. Decades of widespread use in the United States have left thousands of sites contaminated with TCE.
In an article published Tuesday in the Journal of Parkinson’s Disease, the authors hypothesize that this pollution could contribute to the global spread of Parkinson’s disease, a neurological disorder characterized by uncontrollable tremors and slow movements. Although the authors were unable to prove a direct link, they cited a number of other studies that suggest TCE may play a role in degenerative brain disorder, and urged further research into the question.
“When Dr Parkinson described the disease in 1817 in London, he reported six people with the disease,” said Dr Ray Dorsey, professor of neurology at the University of Rochester and lead author. “Two hundred years later, the global burden of disease is estimated at more than 6 million people with the disease worldwide. So how to go from 6 to 6 million? Rates are increasing much faster than aging alone could explain. It must be environmental factors. I think TCE and air pollution are big contributors.
Although prolonged or repeated exposure to TCE is known to cause kidney cancer, according to the National Cancer Institute, the authors of the article argue that a link to Parkinson’s disease would significantly increase its risk, especially for brownfield sites that have been converted into subdivisions.
“When a patient tells me about a possible exposure, I Google their location and almost always find a contaminated site,” Dorsey said.
The article draws on more than two dozen research papers documenting the apparent neurological effects associated with TCE exposure and highlights a number of Parkinson’s cases. Citing the ubiquitous nature of the chemical, the document refers to a plume of contamination underlying a portion of Newport Beach, which is considered one of the largest residential communities in California affected by chemical fumes from the inherited contamination.
TCE was first associated with symptoms of Parkinson’s disease in 1969 in a 59-year-old man who worked with the chemical for more than 30 years, according to the article. Much of it was related to workplace exposure, including a woman working with the chemical while cleaning homes and factory workers degreasing and cleaning metal parts. A 2012 study of twins found that occupational or recreational exposure was associated with an approximately 500% increased likelihood of developing Parkinson’s disease.
TCE production in the United States peaked in the 1970s, exceeding 600 million pounds per year. It was commonly used at military bases and industrial sites, and disposed of at hazardous waste facilities.
Today, up to a third of the drinking water supply in the United States may contain TCE, according to the Environmental Protection Agency. But the chemical also threatens indoor air quality, as it can seep from the ground into homes through foundation gaps, where it is then inhaled as vapor.
In Southern California, a region facing a housing shortage, redevelopment of land contaminated by TCE and a host of other chemicals has raised alarm bells among community groups.
The Santa Susana Field Lab, the site where rocket engines were tested in the Simi Hills of Ventura County, was once remote. Today, 700,000 people live within 10 miles of the dormant site, where soil and groundwater are contaminated with more than 300 pollutants, including TCE.
Similarly, in Riverside County’s Jurupa Valley, development over the years has approached the Stringfellow Acid Pits, a closed hazardous waste site that handled TCE.
“Studies have always focused on cancer. And we’ve always said there are other diseases and ancillary diseases that come up with that that they don’t detect,” said Penny Newman, Jurupa Valley resident and founder of the Center for Community Action and Justice. environmental.
“The site itself was isolated in a canyon above the community, and there hadn’t been much development there,” Newman said. “But as the city gets bigger with the freeways, they start looking for any available land. And it’s only in the last few years that people have started looking for how they can grow around the site.
In Newport Beach, Orange County, chemicals in shallow groundwater were left over from a former missile systems testing ground.
From 1957 to 1993, Ford Motor Co. operated a 98-acre aerospace campus where it developed tactical missile systems. After the demolition of the facility, the site underwent environmental remediation and was later redeveloped into residential properties. Some of them included multi-million dollar homes. However, some chemical contamination remained and migrated with groundwater into surrounding areas.
Groundwater in Newport Beach is not used for drinking, and TCE vapor levels were not considered a threat to public health at the time. However, in 2014, the U.S. Environmental Protection Agency Region 9 issued a note on the dangers of breathing TCE vapors. Shortly thereafter, California revised its health thresholds for TCE exposure.
Since 2018, consultants hired by Ford, under the supervision of the Santa Ana Regional Water Quality Board, have conducted soil vapor monitoring in the area surrounding the former site.
“Ford believes that access to a healthy and clean environment is a fundamental human right, including for residents of Newport Beach,” the company said in a prepared statement. “Since 1996, Ford has worked proactively with the Santa Ana Regional Water Quality Control Board to address volatile organic compounds in soil and groundwater. We have regularly provided updates to the community and will continue to do so.
So far, more than 350 residential properties and three commercial properties have had indoor air samples taken. Vapors of TCE and a related solvent – tetrachlorethylene or PCE – were detected above screening levels in 129 homes. Air purifiers were offered to approximately 30 homes where data suggested steam intrusion.
Outside homes, a network of 424 underground probes collects vapor measurements at depth. In some cases, these probes have measured TCE concentrations more than 100 times higher than the California residential limit.
In the communities of Bayridge Park and Belcourt Terrace, two of the most concentrated communities, Ford is working to install underground pipe systems designed to handle underground vapors for about a year, which should reduce indoor TCE levels to state standards, according to Jessica Law, a geological engineer at the water board.
“It’s one of the wealthiest areas in all of the United States,” said Dorsey, who grew up in Newport Beach. “If this happens in a resource-rich area, think about what happens in a resource-poor area.”
Environmental advocates say exposure to TCE is preventable. New York and Minnesota have banned its use, and earlier this year the U.S. EPA determined that TCE poses “an unreasonable risk of harm to human health,” a designation that clears the way for regulation. potential.
In the Jurupa Valley, the California Department of Toxic Substances Control continues to battle TCE contamination that spilled from a long-closed former hazardous waste site. From 1956 to 1972, approximately 34 million gallons of liquid industrial waste were dumped into the evaporation ponds of the Stringfellow Acid Pits in a canyon in the Jurupa Mountains. Pollution escaped as floodwaters carried contaminants off site and into a community below.
The state spent millions of dollars installing a network of wells to extract and treat a plume of contaminated water. Despite substantial progress, monitoring in 2018 found that TCE vapors continued to exceed state health standards.
But after years of drought, which allowed more contaminated water to be treated and disposed of, residents now fear the contamination could spread with rain and melting snow.
“It’s all in that soil,” said Newman of Jurupa Valley. “So if you activate it again and it becomes mobile through underground water, you’re going to cause it to start descending [into the community] Again.”