Superfund Research Program

Perchloroethylene (PCE) in Drinking Water and Cancer Risk

Project Leader: Ann Aschengrau
Grant Number: P42ES007381
Funding Period: 1995 - 2000

Project-Specific Links

Final Progress Reports

Year:   1999  1998  1997  1996  1995 

During the past year, project investigators:(1) interviewed the study subjects; (2) coded, computerized, and prepared the data for analysis; (3) geocoded the subjects' residences; and (4) conducted PCE exposure assessments. In particular, a total of 1,414 individuals were interviewed, including 498 living breast cancer cases, 197 next-of-kin of deceased patients, 532 living controls, and 161 next-of-kin of deceased controls. About 7% of interviewed subjects were later determined to be ineligible, mainly because of their residential history. All interview data were coded and cleaned, and breast cancer risk factors and relevant environmental variables were defined for the analysis. About 99% of the subjects' Cape Cod residences over the past 40 years were geocoded using Arcview (ESRI, Inc.) Geographical Information System (GIS) desktop mapping software. Because many addresses could not be geocoded on the first attempt, primarily due to missing information, a number of resources were reviewed in order to achieve the high geocoding rate. These resources included voter registration lists, telephone books, death certificates, county deeds and assessor records. PCE exposure assessments were conducted using large-scale maps prepared with the GIS. These maps contain detailed information on the water distribution system, and the locations and dates of all subjects' Cape Cod residences. Exposure assessments were conducted using an algorithm that estimates the relative delivered dose of PCE entering a home. The algorithm takes into account the water flow direction and rate, the load on the network, and the year that the pipe was installed. All exposure assessments were conducted without knowledge of a subject's case/control status.