Chemicals May Have Caused Brain Tumors at BP Amoco Naperville Complex, But Study Cannot Identify the Culprits

Contents
Introduction
Building 503
Not an Anomaly
Suspects
A Puzzle
Suits Focus on Ventilation

Introduction (Back to Top)
Preliminary results of a three-year investigation suggest that occupational exposure may have contributed to at least 12 brain cancer tumors among chemical researchers at BP Amoco's Naperville, IL, research complex. The study, however, stopped short of identifying the exact chemical or chemicals to blame for the outbreak.

At least 20 employees at Naperville have developed brain tumors since BP Amoco opened the facility in 1970. Of those, 12 chemical researchers who worked in Naperville's Building 500 complex have developed primary intracranial tumors since 1986. Five of them worked on the same floor of the Building 503 wing, one of two research wings surrounding a core of offices in the complex. Five of the 12 have died.

After three researchers developed malignant brain tumors in 1996, BP Amoco plc (then Amoco Corp.) closed down the third floor of Building 503 and called in researchers from Johns Hopkins University and University of Alabama at Birmingham (UAB) School of Public Health to investigate. The team, led by Elizabeth Delzell of UAB and Peter S.J. Lees of Johns Hopkins, plans to publish its report in a peer- reviewed occupational health journal.

The team focused on the 1676 people who worked in the Building 500 complex. It identified approximately 6000 chemicals that could have caused reactions. The study concludes that occupational exposure may have contributed to the 12 cancers, but could not finger a specific causative agent.

"It's very difficult with small number of cases involved for epidemiologists to determine if the tumors were work-related," says company spokesperson Vicki Kastory. "But we were able to find a number of clues."

The study noted that researchers who developed glioma had worked with low-level ionizing radiation and n-hexane more frequently than the control group. "It is unlikely ionizing radiation or n-hexane alone were responsible, but rather something used in combination with those materials," says Kastory.

Lawsuits against the company charge the facility had a faulty ventilation system. BP Amoco maintains that it used the best available technology and that it was regularly tested.

"While it is frustrating that we do not have a conclusive answer," says company health investigation task force chair Jim Lowry, "we are hopeful that the clues the investigators have uncovered will in some way help health scientists in their efforts to identify the causes of brain cancer." Lowry, a company researcher, formerly worked in Building 500.

Building 503 (Back to Top)
BP Amoco opened the 170-acre Naperville research and development complex in 1970. It has employed 6,962 people since then, 1,676 in the Building 500 complex. The entire research center now employs about 850 people, down from 2000 in 1990.

Investigators found BP Amoco Naperville Complex employees had developed 13 benign and six malignant intracranial tumors between 1982 and 1998. Five of the six researchers who developed malignant tumors worked on the third floor of Building 503. Of the five, three had worked in the same laboratory, though Kastory says that proved a false lead.

The first tumor reported by a researcher in Building 503 occurred in 1986. It went unremarked. In 1989, however, two more researchers were diagnosed with glioma, a malignant and inevitably fatal cancer affecting the cells that support and insulate the nerves of the brain.

BP Amoco launched its own investigation in 1989. It failed to link the tumors to occupational exposure. Instead, the report concluded the cases were a cluster, a statistical anomaly. It asked the Mayo Clinic and University of Illinois-Chicago to review the study in 1989. The reviews found medical or scientific evidence to link the brain cancers to the workplace, says Amoco.

In April 1996, shortly after a fourth and fifth researcher were stricken with gliomas, BP Amoco closed all 39 laboratories and offices on the third floor of Building 503. It also hired the Johns Hopkins-UAB investigators to investigate the problem.

Not an Anomaly (Back to Top)
The study found that white males working in Building 503 from the late 1970s through the mid-1980s were eight times more likely to suffer brain cancer than the general population. All six people with glioma were male chemical researchers in the Building 500 complex.

All were long-term employees who had worked at the center between nine and 24 years. All worked in the building between the mid-70s and early-80s. Many of them worked on projects involving similar chemicals and agents.

In addition to the six people diagnosed with glioma, six other Building 500 researchers had benign intracranial tumors. These included two Schwannomas, two meningiomas, and two pituitary adenomas.

The rest of the Naperville site had 13 benign intercranial tumors and one glioma. The study says this is statistically average. The Johns Hopkins-UAB team found no unusual patterns in work location, dates of employment, or work activities among people diagnosed with benign intracranial tumors or any cancers other than glioma. This suggests no other cancers are linked to work at the facility.

Suspects (Back to Top)
The preliminary report found two potential suspects in the cancers. People who developed glioma had worked with low-level ionizing radiation sources and n-hexane (a solvent not known to cause any form of cancer in humans) more frequently than the control group.

According to Amoco, there is no causative link between brain cancer and the known types and magnitudes of exposures experienced by the researchers. The company believes n-hexane and ionizing radiation may have played a role with other chemicals to cause the outbreak. The company stopped using n-hexane in experiments when research showed it caused peripheral nervous system damage.

While company records indicate the individuals experienced less exposure to ionizing radiation in their entire lifetimes than is allowable under current regulations for a single year, further investigation will be conducted to determine the possible sources and specific levels of exposure experienced by the cases.

A Puzzle (Back to Top)
"This investigation has been like piecing together a puzzle," says Lowry. "We have several parts assembled, but not all the pieces have come together yet. While we will continue our search for answers, one thing is certain, and that is that the health and well being of our current and former employees remains our number one priority."

BP Amoco has called in many outside experts to evaluate potential health and safety problems. Industrial hygienists have monitored work practices. Third-party experts have investigated air, water and soil quality; tested ventilation system and laboratory hoods; and performed safety audits on laboratory processes. Technicians have scoured the facility with radiation detectors. They have found nothing unusual, says BP Amoco.

The company continues to take additional steps to address the health concerns of employees and ensure their safety. It plans ongoing workforce health monitoring and counseling, and establishment of safe work practices for agents identified in the study. It reaffirms its commitment to the most modern laboratory equipment and training. It also promises to share data on further research into the causative roles of chemicals handled by stricken workers, and to publish the results of its investigations.

BP Amoco will also fund brain cancer research and reach out to colleagues afflicted by brain cancer.

More than one dozen of those colleagues or their surviving families have sued the company. Most suits charge that faulty ventilation systems allowed dangerous chemical to escape into the air. Several of the suits were consolidated in Cook County Circuit Court before Judge Judith Cohen.

Suits Focus on Ventilation (Back to Top)
A lawsuit filed August 25, 1998, seeks payments for seven cancer-stricken workers, three of whom have died. The suit charges Amoco with "reckless disregard for the health and well-being" of its employees by exposing them for prolonged periods to "defective, unsafe and/or unreasonably dangerous chemicals."

The suit says Amoco "failed to study, investigate, determine, impose or comply with reasonable standards and regulations to protect and promote the health and safety or to minimize the dangers." It also says 19 current or former Naperville employees were diagnosed with head tumors, and that four have died of them.

"Company officials knew of the dangers at the lab as well as the faulty ventilation system which created an unsafe working condition for years," says Chicago attorney Robert Clifford.

Amoco installed the original constant-flow fume hoods in 1970, when the building opened. The system was upgraded in the early 1990s to use variable air volume hoods and airfoils. The new system increases hood exhaust volumes as sashes rise, keeping air speed under the hood more constant.

Some suits suggest that the old system reentrained chemical exhaust. In 1997, Amoco BP tested a scale model of the Building 500 complex in a wind tunnel in order to measure the amount of reentrained exhaust air under wind conditions simulating meteorological data from 1970 on.

According to Amoco BP, "the study found that reentrainment was uncommon, and occurred at low levels in the worst conditions. The exhaust system design was deemed "very good" based on today's standards. The current system was found to have even less reentrainment, with performance approaching best achievable technology."

Details: James D. Lowry, Chair, BP Amoco Health Investigation Task Force, 150 W. Warrenville Rd., Naperville, IL 60563. Phone: 630-420-3806. Fax: 630-420-3647.