Chemical Company Rohm and Haas Co. conducted its own study in 2004 and found no significant links among 15 workers who developed brain tumors at its research campus in Spring House since 1973. All but one has died. However, the lawyer representing several plaintiffs states, "there is evidence enough to establish a workplace link to these cancers."

Nearly 6,000 technicians , chemists and others have worked at the campus since its opening in 1963, including about 1,000 people who work there presently. Scientists work on and develop chemicals used in household and industrial products, from shampoos to paints to dashboards in cars.

The same attorney representing former and current employees is also pursuing individual negligence lawsuits against Rohm and Haas on behalf of two longtime scientists diagnosed with glioblastoma, an aggressive type of brain cancer.

One of them died in 2003 at age 50, two years after he was diagnosed. Five of the 15 workers described in Rohm and Haas study were diagnosed with glioblastoma. The other, a 57 year old man, has sought treatment for the disease at a Texas cancer center but the treatment is not covered by his health-care network..

Both men worked on agricultural products such as pesticides. According to their lawyer, the three others diagnosed with glioblastoma worked near them at the Spring House campus. The company has since sold its agricultural unit.

Spokesman for Rohm and Haas states the company is currently reviewing the death certificates of former campus employees, which is expected to be finished in November 2006.