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Chromium Industry Withheld Evidence of Workplace Cancer Risk

Published by MAC on 2006-02-24

Chromium Industry Withheld Evidence of Workplace Cancer Risk


24th February 2006

Scientists funded by the chromium industry withheld from the U.S. government key data supporting a strict standard for workplace exposure to hexavalent chromium while the chromium industry fought to block a lower federal workplace exposure level for the potentially deadly metal, according to secret industry documents published Thursday in a scientific journal.

The paper published in the peer-reviewed journal "Environmental Health," is based on evidence of the manipulation in documents that surfaced following the bankruptcy of the Industrial Health Foundation, a group funded by the chromium industry.

Researchers from the Washington-based Public Citizen Health Research Group, and the George Washington University School of Public Health and Health Services found the documents as the result of an Internet search and through the Public Access to Court Electronic Records system.

The revelations come less than a week before the U.S. Occupational Safety and Health Administration (OSHA) is required by court order to issue a new workplace exposure standard for chromium, a known carcinogen. OSHA estimates that 380,000 workers are exposed to hexavalent chromium, which is used in chrome plating, stainless steel welding and the production of chromate pigments and dyes.

The agency has repeatedly requested studies on the health effects of lower exposures to the metal. Despite having completed a 2002 study that found an increase in lung cancer deaths from moderate exposures to chromium five times greater than workers who were not exposed, the chromium industry did not notify OSHA of the study’s existence.

In addition, industry-funded researchers manipulated the data to obscure the evidence that hexavalent chromium was carcinogenic at lower exposures, the Public Citizen and George Washington paper claims.

The industry has denied doing anything wrong.

Currently, OSHA does not regulate hexavalent chromium on the basis of its carcinogenicity. The agency’s current Permissible Exposure Limit (PEL) of 52 ug/m3 was originally recommended in 1943 by the American National Standards Institute as a level adequate to prevent nasal perforations in chromium-exposed workers.

The same standard exists today although the federal Agency for Toxic Substances and Disease Registry, a division of the Centers for Disease Control says several studies have shown that hexavalent chromium compounds can increase the risk of lung cancer. Animal studies have also shown an increased risk of cancer.

The World Health Organization (WHO) has determined that hexavalent chromium is a human carcinogen.

The Department of Health and Human Services (DHHS) has determined that certain hexavalent chromium compounds are known to cause cancer in humans, and the EPA has determined that hexavalent chromium in air is a human carcinogen. Public Citizen and the Paper, Allied-Industrial, Chemical and Energy Workers International Union (PACE), now part of the United Steelworkers, successfully sued OSHA in 1997 and 2002 for delaying the promulgation of a new standard. In April 2003, the U.S. Court of Appeals for the Third Circuit ordered the agency to do so by January 18, 2006, but has extended that deadline to February 28, 2006.

After the court ruling, OSHA began its rulemaking process, and, in its proposed rule and again in public hearings that took place in February 2005, actively sought data on exposure to lower levels of hexavalent chromium.

Anticipating that OSHA might attempt to reduce worker exposure to hexavalent chromium, in 1997 the industry commissioned a study that would combine the mortality data at four sites – two in the United States and two in Germany.

The study, completed in 2002, showed a statistically significant elevated risk of lung cancer death when workers were exposed to lower levels of hexavalent chromium. The study protocol explained that multiple study sites were necessary to gain sufficient statistical power.

The industry never published this four-site study, not did it provide the findings to OSHA. Public Citizen did so in June 2005.

To bolster its position that exposure to lower levels of hexavalent chromium were not harmful to workers, the industry split the results of this study in two, reducing its statistical strength.

A paper about the two U.S. plants was published in the "Journal of Occupational and Environmental Medicine" weeks before OSHA’s public comment period was scheduled to end. The published paper, based on only three lung cancer deaths and limited follow-up, concluded that reductions in exposure to hexavalent chromium may have reduced the incidence of lung cancer. The industry then highlighted the study in comments to OSHA.

In the second paper, describing the two German sites, the industry-funded researchers combined the results from the “intermediate” and “high” exposure groups.

Public Citizen and George Washington researchers say that doing so obscured the fact that in the full four-site study, the risk of lung cancer death was elevated at even the intermediate level – a level close to that considered by OSHA for a new exposure limit. "Together, these two papers were intended to prevent OSHA from promulgating a stricter exposure limit" for hexavalent chromium, the researchers claim.

“Polluters and manufacturers of dangerous products should not be permitted to hide data that are important for protecting the public’s health,” said Dr. David Michaels, lead author of the report and director of the Project on Scientific Knowledge and Public Policy at the George Washington University School of Public Health and Health Services.

Michaels and co-author Dr. Peter Lurie, deputy director of Public Citizen’s Health Research Group compare the chromium industry's manipulation of scientific results to the behavior of the tobacco and pharmaceutical industries.

"The tobacco industry, for example, used the attorney-client privilege to shelter scientific studies from disclosure; it also funded apparently independent organizations to provide a patina of credibility for its work. Pharmaceutical manufacturers have withheld unfavorable clinical trial results and have disparaged research that produced unwelcome findings," Michaels and Lurie write.

“The circumstances regarding this study raise troubling questions about the ability of the government to effectively issue rules protecting public health when studies are conducted, controlled and selectively published or provided to the rulemaking agency by the regulated industry,” said Lurie. “Corporate America loves to decry what it calls junk science," Lurie said, "but there’s no question that the industry was the producer of the junk in this case."

The report, "Selected science: an industry campaign to undermine an OSHA hexavalent chromium standard," is online at:

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