Dry Cleaning Chemical Linked to Triple Risk of Dangerous Liver Disease, Study Finds

Exposure to tetrachloroethylene (PCE), a common chemical used in dry cleaning and various consumer products, has been linked to three times the risk of developing significant liver fibrosis, according to new research from the Keck School of Medicine of the University of Southern California.

The groundbreaking study, published in the journal Liver International, analyzed data from the National Health and Nutrition Examination Survey (NHANES), which provides a nationally representative sample of the U.S. population. Researchers examined blood samples from 1,614 adults aged 20 and older collected between 2017 and 2020.

Approximately 7% of the U.S. population had detectable levels of PCE in their blood, the study found. Those with PCE exposure were three times more likely to have notable liver fibrosis compared to those without exposure. The researchers also identified a concerning dose-response relationship, meaning higher levels of PCE exposure corresponded with greater likelihood of developing liver fibrosis.

“We were surprised that so many people have detectable PCE in their blood, and that the link with liver scarring was so strong,” said lead author Dr. Brian P. Lee, hepatologist and liver transplant specialist with Keck Medicine of USC. “Since prior studies have mainly focused on people who are exposed to PCE for work, I think people will be surprised by their exposure, even when they don’t directly work with PCE.”

Liver fibrosis—a buildup of scar tissue in the liver—can progress to more serious conditions such as liver cancer, liver failure, or death if left unchecked. The condition represents a growing public health concern in the United States.

Interestingly, the study found that higher-income households faced greater risk of PCE exposure, possibly due to increased use of dry cleaning services. However, Dr. Lee noted that workers in dry cleaning facilities may face elevated risks due to prolonged, direct exposure to the chemical.

The research also revealed that traditional risk factors for liver disease—such as alcohol consumption and obesity-related liver fat accumulation—did not appear to significantly contribute to liver fibrosis when PCE was detected in the blood.

“Patients will ask, how can I have liver disease if I don’t drink and don’t have any of the health conditions typically associated with liver disease—and the answer may be PCE exposure,” Dr. Lee explained.

Beyond liver damage, PCE exposure carries additional health risks. According to the U.S. Environmental Protection Agency (EPA), long-term exposure has been linked to neurological impairment, mood and behavior changes, kidney damage, developmental and immune system effects, and increased cancer risk. Short-term exposure may cause upper respiratory irritation, neurological symptoms (dizziness, headaches, fatigue), and kidney dysfunction. Pregnant women and children are particularly vulnerable to developmental effects.

In recognition of these dangers, the EPA has determined that PCE presents an “unreasonable risk” under certain use conditions, according to the Toxic Substances Control Act. In December 2024, the agency issued a Final Rule restricting PCE’s “manufacture, import, processing, distribution, use and disposal” for many applications. The following month, the EPA released compliance guidance for dry-cleaning and energized electrical cleaning.

“In 2024, the EPA announced a ban on PCE for consumer and commercial uses with a 10-year phaseout—however, this ban is now being reconsidered,” Dr. Lee noted. “This current study provides data to inform policymakers.”

The researchers acknowledged several limitations to their study. Because it examined PCE levels at a single point in time, it couldn’t definitively prove a causal relationship between chemical exposure and liver fibrosis. Additionally, the findings may not apply globally, as the study only included U.S. adults.

Dr. Lee emphasized that further research is needed to confirm the role of environmental toxins in liver disease risk. “No doubt there are other toxins in our environment besides PCE that are dangerous to the liver,” he added.

The study, supported by the National Institute on Alcohol Abuse and Alcoholism and the National Institutes of Health, highlights the importance of liver disease awareness and screening.

“Liver disease is growing in the United States at an alarming rate—the problem is that liver disease doesn’t normally cause symptoms until you have very advanced disease,” Dr. Lee said. “Knowing the contributors to liver disease—on top of alcohol, diabetes and being overweight—can help you know whether you need to talk to your doctor about getting screened.”