Parkinson’s disease is the fastest growing neurological disease in the world.1 And a new study finds that a common dry cleaning solvent that has been used for nearly a century may be contributing to this increase. The chemical, trichlorethylene (TCE), has been detected in up to 30% of the U.S. drinking water supply and remains in the soil and air long after industrial use has ceased.2
TCE exposure doesn’t have to come from working in a factory or chemical plant, it also comes from breathing outdoor air near contaminated areas or using contaminated groundwater. TCE was once prized for its ability to dissolve grease and dry cleaning fabrics, but it is now recognized as a persistent neurotoxin.
When inhaled or ingested, it quickly crosses the blood-brain barrier and damages the same neurons destroyed in Parkinson’s disease. Evidence from human and animal studies shows that even moderate chronic exposure gradually erodes brain health by disrupting mitochondrial function (the energy engine inside cells), causing oxidative stress and inflammation.
These findings point to a deeper problem. Environmental toxins have been quietly weakening our neurological health for generations. Understanding how exposure to these solvents changes brain chemistry and increases the risk of Parkinson’s disease is the first step to protecting yourself and your loved ones.
TCE exposure linked to increased risk of Parkinson’s disease in large US study
Parkinson’s disease, characterized by tremors, muscle stiffness, slow movements and balance problems, occurs when brain cells that produce dopamine begin to die. Most people notice early symptoms, such as decreased arm swing, changes in handwriting, or trouble sleeping, well before diagnosis. Over time, it progresses to more serious complications that affect speech, memory, and mobility. In a study published in Neurology, researchers linked long-term solvent exposure to an increased incidence of Parkinson’s disease.3
Researchers analyzed the medical records of more than 1.3 million older adults across the United States to determine whether living in areas with high levels of airborne TCE was associated with a greater risk of developing Parkinson’s disease. Because it remains in the environment for decades, even communities far from active plants remain exposed through soil, air and groundwater.
• Older adults exposed to more TCE had a marked increase in Parkinson’s disease diagnoses. Individuals living in the top 10% of TCE concentrations had an approximately 10% higher risk of developing Parkinson’s disease than individuals living in the lowest exposure areas.
The association remained significant after adjusting for age, gender, and regional demographics. The findings are important because Parkinson’s disease usually develops over decades. This means that chronic, low-level TCE exposure contributes to disease development long before symptoms appear.
• The study showed early neurological warning signs in highly exposed areas. Residents in areas with higher TCE levels were more likely to report balance problems, falls, and mild cognitive decline. This often predates the diagnosis of Parkinson’s disease by several years. These early signs serve as clues that environmental exposures are harming brain health long before full-blown disease develops.
• Chemical Hotspots of Neurological Risk Exposure to Geographic Data — When researchers mapped Parkinson’s disease cases across the United States, they found distinct clusters around industrial areas and known TCE emitting facilities, including in Oregon, Indiana and parts of the Midwest. The risk steadily decreased the further people lived from these emissions sites. This pattern provides strong real-world evidence that environmental pollution directly affects neurological disorders.
• TCE persists in the body and environment, making exposure difficult to avoid. Even after the plant closes, TCE residues remain trapped in soil and groundwater for decades. Vaporized smoke can leak into homes and workplaces through basements and plumbing systems, exposing people without their knowledge. Because of this, simply living near an old industrial site can have long-term neurological consequences.
Knowing that even small, repeated exposures increase the risk of Parkinson’s disease highlights the need to purify the air and water in your home, avoid using chemical-based degreasers, and clean contaminated areas. Research shows that protecting the environment is inextricably linked with protecting brain health.
Laboratory research reveals how TCE causes nerve damage at the cellular level.
Before researchers began investigating TCE’s effects on humans, early laboratory experiments revealed the role this solvent played inside the brain itself. The study, published in Neurobiology of Disease, explored how TCE affects the brain’s motor control centers using older mice, which closely mimic human vulnerability to Parkinson’s disease.4
After just six weeks of daily TCE exposure, researchers observed a significant loss of neurons in the substantia nigra (the same region that degenerates in people diagnosed with Parkinson’s disease). These findings confirm that the solvent itself, not just genetic predisposition or other toxins, has a toxic effect on brain tissue.
• Older brains have been shown to be particularly vulnerable to the toxic effects of TCE. The study showed that aging magnifies damage, suggesting that older people with lifelong environmental exposure face greater neurological risks.
Age-related decline in mitochondrial function with continued exposure has been shown to accelerate cell death. This means that protecting your brain health becomes more important as you age, because decades of environmental exposure quietly erode the brain’s ability to regenerate healthy neurons.
• TCE interfered with energy production inside brain cells — TCE increases oxidative stress by interfering with mitochondria, the power generators of cells. Oxidative stress occurs when the body’s antioxidant defenses are overwhelmed and cells are damaged.
This imbalance causes inflammation and eventually kills dopamine neurons. Solvents “short-circuit” the brain’s energy systems, making neurons unable to perform the demanding tasks of maintaining movement and coordination.
• The solvent caused a dangerous protein buildup inside the neurons. TCE exposure increased the buildup of sticky proteins that clump together in the brains of people with Parkinson’s disease. When these clumps form, they disrupt normal brain signaling, creating a series of dysfunctions that mirror the human disease process. Chemical contamination caused the same toxic brain changes seen in Parkinson’s disease, even in the absence of genetic risk factors.
• TCE flipped a switch that accelerated brain cell damage. Researchers found that TCE interferes with the way brain cells clear waste and regulate inflammation. When that system becomes overactive, it sets off a chain reaction of stress and damage inside cells, leading to faster loss of neurons that control movement. In other words, TCE disrupted the brain’s cleaning process, turning it from protective to destructive.
Practical Steps to Protect Your Brain and Enhance Cell Health
Protecting your brain from neurodegenerative diseases starts with protecting your cells, the engines that power your mind and body. The same environmental toxins linked to Parkinson’s disease, such as TCE and pesticides, also attack mitochondria. When mitochondria become weak, every system in the body is impaired, from muscles to mood. But through daily choices, you can restore mitochondrial function, reduce exposure to toxins, and lower your risk of long-term neurological decline.
1. Check if your surroundings are putting you at risk — If your home or workplace is near an old dry cleaning facility, military facility, or manufacturing site, you may be exposed to residual solvents like TCE. Contact your local water supplier for recent test results, request a full contamination report, and find out if there are any vapor intrusion sites in your area. Knowing your exposure risks gives you the power to take action before your health is affected.
2. Clean the water thoroughly before it gets on your body — Every sip and shower counts when it comes to reducing toxins. Choose a high-quality water purification system to capture solvents, metals and pesticide residues. Purifying your water protects your entire body, relieving strain on your brain, liver, and kidneys while keeping your cells free of harmful chemicals.
3. Prevent chemical vapors from entering your home — Industrial solvents travel upward through the ground and leak through cracks in concrete floors, entering indoor air unnoticed. Use exhaust fans or air exchangers to enhance ventilation and seal foundation gaps to block invisible gases.
A vapor barrier adds an extra layer of protection, but simple steps like using an air purifier and keeping fresh air flowing through your home can help reduce pollution levels and protect your family’s health.
4. Avoid chemical exposure whenever possible — When possible, choose organic produce to limit pesticide residues, avoid lawn and garden chemicals, and switch from conventional dry cleaning to water-based or carbon dioxide cleaning. All of the toxins you eliminate take pressure off your body and give your cells space to recover and thrive.
5. Build brain resilience from within — Protecting your brain starts with how you nourish and care for your body every day. Exposure to sunlight daily to maintain healthy vitamin D levels, which regulate brain-protecting genes and reduce inflammation. While your gut heals, fuel your mitochondria with about 250 grams of healthy carbohydrates each day, starting with fruit and white rice.
Strengthen your gut by avoiding ultra-processed foods, including seed oils, and gradually add foods rich in fiber, such as root vegetables and legumes. Regular movement and deep sleep further enhance oxygen flow and toxin removal, giving your brain the energy and clarity it needs to stay sharp throughout life.
Protecting your cellular health through diet, toxin reduction, and lifestyle choices will not only prevent disease, but preserve your clarity, energy, and independence for years to come. Every small step toward a cleaner environment and stronger mitochondria brings you closer to lasting neurological health.
FAQs About TCE Exposure and Parkinson’s Disease
cue: What is TCE and why is it dangerous?
no way: TCE is a solvent once used in dry cleaning, metal degreasing, and manufacturing. It is now recognized as a neurotoxin that persists in soil, groundwater and air for decades. When inhaled or ingested, it penetrates the brain and damages dopamine-producing neurons, increasing the risk of Parkinson’s disease.
cue: How common is TCE contamination in the United States?
no way: TCE has been found in up to 30% of the U.S. drinking water supply and at thousands of contaminated industrial or military sites. Areas far from active plants are also at risk because TCE moves through the soil and evaporates into indoor air.
cue: What does new research reveal about Parkinson’s disease and TCE exposure?
no way: A neurological study analyzed more than 1.3 million American adults and found that those living in areas with the highest TCE concentrations had an approximately 10 percent higher risk of developing Parkinson’s disease.5 Studies in the neurobiology of the disease have shown that TCE exposure damages brain cells by disrupting energy production, causing inflammation, and causing buildup of toxic proteins. This replicates the same brain changes seen in human Parkinson’s disease cases.6
cue: How can I reduce my exposure to TCE and other solvents?
no way: Check to see if your home or workplace is near a known contaminated site, and contact your local water supplier for a detailed report. Use high-quality filtration systems for drinking and bathing water, improve indoor ventilation, and seal cracks in basements or foundations to prevent vapor intrusion. Avoid conventional dry cleaning and household degreasers that use harsh chemicals.
cue: What daily habits help protect your brain from environmental toxins?
no way: Support your body’s defenses by optimizing vitamin D through sunlight exposure, maintaining gut health, and eating a nutrient-dense diet that strengthens your mitochondria. Regular exercise and quality sleep also help the brain eliminate toxins and remain resilient to environmental stressors.
