The Previous Studies and Findings

Case-Control Study Findings

The first Spring House epidemiological study was an exposure assessment investigation led by Rohm and Haas Company epidemiologist Arvind Carpenter starting in June 2002. Dr. Carpenter and his team reviewed all known diagnoses of brain cancer among employees who had worked at the facility and compared their exposures to those employees (matched on race, gender, date-of-birth, date-of-hire, and date-of-death) who did not have brain cancer. This methodology, called a case-control study, was used to identify potential issues of concern in the shortest amount of time.

Upon additional investigation of death records obtained through the National Death Index, the study team found that 12 Spring House employees had been diagnosed with malignant brain tumors and 3 employees with benign tumors.

The study team consisted of 22 Rohm and Haas health professionals, including physicians, industrial hygienists, and chemists, which reviewed more than 2,000 work-related documents and 20,000 individual chemicals sorted into 36 categories. In all, more than 100 risk factors were evaluated as part of this study.  An outside panel of experts was engaged to review the design and findings of the study. The study’s findings, which were announced in January 2004, concluded that there was no statistically significant association between brain cancer and any workplace chemical, category of chemicals, building location, business at Spring House or other risk factor. 

Cohort Mortality Study Findings

A second study, completed in 2007 by Dr. Carpenter and his team, examined all causes of death, including brain cancer, for all employees who had died since 1963, when the Spring House facility first opened.  An outside panel of scientists reviewed the format and findings of this study. Preliminary findings concluded that there was no statistically significant increase in the Spring House cohort for any cause of death, including brain cancer, compared with rates among the general U.S. population or the Commonwealth of Pennsylvania.