The Multinational Monitor

November 2000 - VOLUME 21 - NUMBER 11


Carcinogenicity Alert

OSHA's Failure to Regulate
Hexavalent Chromium
and the Price Workers Pay

By Peter Lurie and Sidney Wolfe

The Clinton Occupational Safety and Health Administration (OSHA) appears set to end its eight years in office without proposing a single new regulation of a hazardous chemical, though not for lack of regulatory candidates.

Since the beginning of the Clinton administration, Public Citizen's Health Research Group (HRG) and the Oil, Chemical and Atomic Workers Union (OCAW, now the Paper, Allied-Industrial, Chemical and Energy Workers International Union, PACE) have urged OSHA to issue new standards for hexavalent chromium, a carcinogenic chemical used in the production of metal alloys such as stainless steel, chrome plating and pigments.

Hundreds of thousands of U.S. workers are exposed to hexavalent chromium. Erin Brockovich, portrayed by Julia Roberts in the recent movie that took her name as its title, fought for compensation for residents of a California community whose groundwater had been contaminated with hexavalent chromium.

For over two decades, OSHA has sat on a recommendation from the National Institute of Occupational Safety and Health (NIOSH) to drastically lower hexavalent chromium workplace exposure levels. In 1993, HRG and OCAW petitioned for new regulations, and in 1997 filed a lawsuit to force an emergency rulemaking. Yet OSHA has failed to act.

New data - obtained by HRG prior to publication after a protracted battle using the Freedom of Information Act - published in the August 2000 American Journal of Industrial Medicine confirms more clearly than ever before that hexavalent chromium is a potent lung carcinogen. The newly published findings show that OSHA's failure to reduce workplace exposure to the chemical will lead to the deaths of thousands of the hundreds of thousands of hexavalent chromium-exposed workers.

The newly published study is the largest, most comprehensive study of the toxicity of hexavalent chromium ever conducted. It demonstrates that lung cancer death rates were almost double what would otherwise have been expected for exposed workers.

OSHA's Failure to Regulate
The first case of chromium-induced cancer was reported in 1890. Since then, the evidence of hexavalent chromium carcinogenicity has continued to accumulate.

Although there are studies demonstrating increased risks of lung cancer in chromate pigment industry and plating industry workers, the primary evidence of the carcinogenicity of hexavalent chromium came from two studies conducted among chromium production plant workers. In the so-called Mancuso study, researchers followed 332 workers hired between 1931 and 1937 and found markedly elevated risks of lung cancer. The other major study, by Hayes, et al., demonstrated that lung cancer death rates were twice as high in workers at a Baltimore chromate production plant as in other city residents. The Environmental Protection Agency, the National Toxicology Program and the International Agency for Research on Cancer have all declared chromium a carcinogen.

NIOSH recommended in 1975 that the Permissible Exposure Limit (PEL) for total chromium be lowered from the current 100 g/m3 (micrograms per cubic meter) to approximately 2 g/m3 as an eight-hour time-weighted average. In July 1993, HRG and OCAW filed a petition with OSHA requesting that the agency issue an Emergency Temporary Standard to lower the PEL for total chromium to 0.5 g/m3. The petition included a risk assessment that estimated that 22 percent of workers exposed for a working lifetime to chromium levels at the current PEL would develop lung cancer.

OSHA contracted for its own risk assessment, conducted by K.S. Crump Division of ICF Kaiser. That risk assessment, based on lifetime exposures of 50 g/m3 (as opposed to 100 g/m3 in the HRG/OCAW petition), estimated that 9-to-34 percent of workers would contract lung cancer as a result of hexavalent chromium exposure.

On March 8, 1994, OSHA denied the petition for an emergency standard, but admitted in its response that "there is clear evidence that exposure ... at the current PEL ... can result in an excess risk of lung cancer" and other related illnesses. The agency also said it would publish a Notice of Proposed Rulemaking (NPRM) in the Federal Register "not later than March 1995." Over five years later, this has still not taken place.

After the promised NPRM failed to transpire, HRG wrote to OSHA, which then promised an NPRM in July 1996 and a final rule by April 1998. With no NPRM in sight, OCAW and HRG sued OSHA in September 1997 in the United States Court of Appeals for the Third Circuit in Philadelphia. In March 1998, the court ruled against OCAW and HRG, in effect leaving the pace of rulemaking at OSHA's discretion. In its submissions to the court, OSHA indicated that an NPRM would be published by September 1999. In April 2000, OSHA published its semi-annual agenda, and now anticipates an NPRM in June 2001, six years later than its original promise.

History of the Study
Meanwhile, to investigate the relationship between workplace hexavalent chromium exposure and health, the Environmental Protection Agency (EPA) entered into a Cooperative Agreement with Dr. Peter Lees at Johns Hopkins University School of Hygiene and Public Health. The study was to assess the relationship between chromium exposure and various health outcomes, including lung cancer.

In November 1994, John Martonik, acting director of OSHA's Directorate of Health Standards, wrote to the EPA stating that the study was "important to our rulemaking process" and inquiring when the study might be completed.

Herman Gibb of the EPA's Office of Research and Development and the first author of the new article, responded that "we expect a final report should be available by June 1995."

Indeed, by 1995, the study was sufficiently complete to permit a presentation at the 11th International Symposium on Epidemiology in Occupational Health. The authors presented similar results at a conference in 1996, followed by another in 1997 and two in 1999. They added no additional raw data to the database after 1995, and the 1995 and 1999 presentations present identical mortality ratios. These are only slightly changed in the finally published August 2000 article.

While the study was essentially completed in 1995, and although the researchers and the sponsoring agency were fully aware that these data were critical in a federal rulemaking procedure that would affect hundreds of thousands of workers, the study results remained unpublished for half a decade.

The Chemical Manufacturers Association, the National Association of Metal Finishers, American Electroplaters and Surface Finishers and other industry groups capitalized upon the delay by writing a series of letters to OSHA requesting that any rulemaking be postponed until the results were published.

The Study Results
The EPA/Johns Hopkins study included 2,357 men who worked at the chromate production plant in Baltimore originally described by Hayes. The workers began employment between 1945 and 1974. The researchers measured chromium levels randomly during much of the study period and calculated chromium exposure cumulatively, adjusting for the employment duration and work location of each particular worker. Mortality levels in the workers were compared to those of otherwise similar persons in the state of Maryland. The study adjusted for age, race and smoking status at the time of initial employment.

These methods are a substantial improvement over those available to Mancuso. The EPA/Johns Hopkins study has seven times as many workers, five times as many person-years of follow-up and twice as many lung cancer deaths. It measured hexavalent chromium directly and concurrently (not indirectly and after-the-fact as in the Mancuso study), had smoking data and used multivariate analysis, a statistical technique for measuring the independent contribution of different variables. The present study was also able to assess the hazards of chromium exposure at much lower levels than in the Mancuso study.

Overall, lung cancer deaths occurred at 1.8 times the rate that would have been expected for otherwise similar Maryland residents.

The researchers found a strong dose-response relationship between cumulative hexavalent chromium exposure and the risk of death from lung cancer. Exposure levels similar to the OCAW/HRG-recommended permissible exposure limit were associated with a risk of lung cancer 1.6 times higher than would be otherwise have been expected.

The researchers also controlled for smoking, decade of employment and race.

"The current study confirms the elevated lung cancer risk from hexavalent chromium exposure observed in other studies," the authors conclude, "and presents the best opportunity to date of evaluating the lung cancer exposure-response relationship from exposure to hexavalent chromium."

In another study based on the same cohort, also published in the August issue of the American Journal of Industrial Medicine, the same authors evaluated the relationship between hexavalent chromium exposure and skin and nasal irritation. Nasal irritation and nasal ulceration were each diagnosed in more than 60 percent of the cohort. Nasal ulceration, skin irritation and perforated eardrums were all more common with increasing exposure to hexavalent chromium. The median hexavalent chromium exposure at the time of these and other clinical findings was generally 20 g/m3 - one-fifth of the current OSHA standard.

Preventable Deaths
Five years since the findings of the lung cancer study were first presented, the data are now fully public. The findings are strong and the methods rigorous. The results show that OSHA has been guilty of a massive dereliction of duty. The agency's failure to issue new regulations will lead to the preventable deaths of thousands of workers.

Drs. Peter Lurie and Sidney Wolfe are the deputy director and director of Public Citizen's Health Research Group.