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High Levels of Carcinogens in Dry-Cleaning, Study Shows

Paul Roepe

Prof. Paul Roepe led the Georgetown study, which found potentially cancerous chemicals in polyester, cotton and wool clothing that had been dry-cleaned.

August 30, 2011 – Georgetown researchers have found that perchloroethylene (PCE), a potentially carcinogenic dry cleaning solvent, is retained in dry-cleaned clothes made of polyester, cotton or wool.

The levels increase with repeat cleanings, according to the researchers, whose work appeared Aug. 30 online in Environmental Toxicology & Chemistry.

More Studies, Quickly

“The question is, can the levels of PCE we find be absorbed through the skin or inhaled in quantities large enough to harm people,” says Georgetown professor Paul Roepe, who supervised the study. “We don’t have the complete answers to those questions, but I think we know enough to suggest that more studies should be done very quickly.”

The Georgetown study is the first to quantify the amounts of PCE in dry-cleaned clothing, according to Roepe, a professor in Georgetown’s chemistry department as well as the biochemistry and molecular & cellular biology department.

Cancer Risk

Human PCE exposure has been linked to elevated risk of cancer, according to the U.S. Environmental Protection Agency (EPA), which has labeled PCE a likely carcinogen.

The researchers found that PCE, absorbed through inhalation, mouth or skin contact, is slowly emitted from dry-cleaned fabrics even when wrapped in dry plastic wrap.

In a warm, closed environment such as inside a car or a closet, the chemicals could be expelled at an even greater rate, the study’s authors say.

Health Issue

The contaminant on the clothing inevitably comes into contact with the wearer’s skin, and is also released into the air inside homes and automobiles.

“We don’t really think about … dry-cleaning as a health issue,” says Katy Sherlach (G‘14), one of two Ph.D. students who conducted the study. “Everybody dry-cleans clothing and you pick it up, you bring it home, you don’t even think about it.”

Scherlach conducted the study with fellow chemistry department Ph.D. candidate Alexander Gorka and Alexa Dantzler, a rising junior at Bishop O’Connell High School in Arlington, Va., who came up with the idea.

Learning Experience

Dantzler was working on a group project for her freshman science class when she had the idea to study the chemicals in dry-cleaned clothes. She found Roepe’s email address on Georgetown’s website and contacted him for help.

“It was really great getting experience in the lab – the training was really wonderful,” says Dantzler, who says chemistry is her favorite subject.

Using a gas chromatography/mass spectrometer, the researchers quantified levels of residual PCE in dry-cleaned samples of wool, polyester, cotton and silk.

Important Findings

They found that polyester, cotton and wool (but not silk) are most prone to retaining high levels of PCE.

“At the end of the day, nobody – I mean nobody – has previously done this simple thing – gone out there to several different drycleaners and tested different types of cloth for retained PCE,” says Roepe, also co-director of Georgetown’s Center for Infectious Disease. “I am enormously impressed with how quickly the dedication of Ms. Dantzler and my two Ph.D. students led to these important findings.”

Related Information

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