Trichloroethylene (TCE) is an industrial chemical widely used for decades. This article explores the nature of TCE, its common uses, how individuals might be exposed, and the scientific understanding of its relationship with cancer, particularly prostate cancer.
What is Trichloroethylene?
TCE is a volatile organic compound (VOC). It is a clear, colorless, nonflammable liquid with a sweet, chloroform-like odor that evaporates easily into the air. Historically, it was extensively used as a solvent to remove grease from metal parts in manufacturing, and in consumer products like paint removers, adhesives, and spot cleaners.
In industrial settings, TCE also served as an extraction solvent for oils, fats, waxes, and in textile processing. While many consumer uses have been phased out, it remains a common environmental pollutant. TCE can contaminate soil and groundwater from spills or improper disposal, and it readily volatilizes. This chemical can persist in groundwater for extended periods due to slow biodegradation under anaerobic conditions.
Investigating the Link: TCE and Prostate Cancer
Scientific bodies have extensively studied TCE’s carcinogenicity. The International Agency for Research on Cancer (IARC) classifies TCE as carcinogenic to humans (Group 1), and the U.S. Environmental Protection Agency (EPA) has determined it poses an unreasonable cancer risk from chronic inhalation and dermal exposure. Cancers associated with TCE exposure include kidney cancer, liver cancer, non-Hodgkin lymphoma, and possibly cervical cancer.
While TCE is a recognized human carcinogen, scientific literature and major health organizations do not explicitly highlight a direct link between TCE exposure and prostate cancer. Epidemiological studies and animal research primarily indicate increased risks for kidney cancer, liver cancer, and non-Hodgkin lymphoma. TCE’s cancer development mechanisms involve its metabolism into compounds that cause cellular damage and mutations, leading to tumor formation in organs like the kidney and liver. However, strong evidence directly linking TCE to prostate cancer initiation or progression is not consistently identified in the scientific consensus.
Sources of Exposure and Risk Factors
Individuals can encounter TCE through various pathways, with inhalation being a primary route due to its volatility. Occupational exposure is a significant concern for workers in industries that manufacture or use TCE, such as metal degreasing, aerospace, automotive, and dry cleaning. Workers may inhale TCE vapors or absorb it through skin contact.
Environmental exposure occurs when TCE contaminates air, water, and soil. Contaminated groundwater, often from industrial discharges or improper waste disposal, can lead to TCE in drinking water supplies. TCE vapors can also migrate from contaminated soil and groundwater into indoor air through vapor intrusion, affecting homes and workplaces.
Historically, consumer products like cleaning wipes, adhesives, and paint removers contained TCE. Using these products, especially in poorly ventilated areas, could lead to inhalation exposure. Risk factors for increased exposure relate to the duration and concentration of contact.
Regulatory Landscape and Public Health Measures
Governmental agencies play a significant role in managing TCE risks. The U.S. Environmental Protection Agency (EPA) has regulated TCE since the 1980s, setting maximum contaminant levels (MCLs) for drinking water at 0.005 mg/L (5 ppb). In December 2024, the EPA finalized a rule to ban most TCE uses, with prohibitions taking effect within one year for consumer and many commercial products, and longer phase-out periods for some industrial uses. This action addresses the unreasonable risk TCE poses to human health.
The Occupational Safety and Health Administration (OSHA) sets permissible exposure limits (PELs) for TCE in occupational settings to protect workers. The National Institute for Occupational Safety and Health (NIOSH) recommends limiting exposure to occupational carcinogens like TCE to the lowest feasible concentration.
State environmental agencies also implement regulations and public health advisories for TCE contamination. Cleanup efforts for contaminated sites are ongoing, often involving complex processes to mitigate TCE spread through groundwater and prevent vapor intrusion into buildings. These measures aim to reduce overall exposure and protect public health from TCE’s known hazards.