ATSDR's trichloroethylene subregistry methods and results: 1989-2000

Area of Science:

• Environmental Health
• Toxicology
• Epidemiology

Background:

• The Agency for Toxic Substances and Disease Registry (ATSDR) established national exposure registries to study human chemical exposure.
• Four chemical subregistries (trichloroethylene, dioxin, benzene, trichloroethane) were created using standardized methods.

Purpose of the Study:

• To evaluate health outcomes in a cohort exposed to trichloroethylene (TCE) through drinking water.
• To assess the long-term health effects and identify persistent health conditions within the TCE Subregistry.

Main Methods:

• A baseline cohort of 4006 individuals with TCE drinking water exposure was established.
• Follow-up assessments were conducted between 1989 and 2000.
• Standardized morbidity ratios compared health condition prevalences with national data from the National Health Interview Survey.

Main Results:

• Persistent excess cases of dermatologic, hematologic, hepatic disorders, and strokes were observed over the registry's lifetime.
• Excess urinary tract disorders were noted, potentially due to systematic bias.

Conclusions:

• First-generation exposure registry methods identified long-term health risks associated with TCE exposure.
• Findings suggest areas for methodological improvement in future environmental exposure studies and registries.