A five year old study demonstrating that exposure to hexavalent chromium can cause lung cancer was released Tuesday by Public Citizen, a public interest advocacy group. Public Citizen obtained the study, funded by the U.S. Environmental Protection Agency under a cooperative agreement with Johns Hopkins University School of Hygiene and Public Health, through the Freedom of Information Act.

Hexavalent chromium is used in the production of metal alloys such as stainless steel, chrome plating and pigments. Lung cancer rates among plant workers exposed to the chemical in their workplaces were almost double what would have been expected among otherwise similar individuals, the study showed.

"The case is closed. Hexavalent chromium is a potent carcinogen. The only remaining question is why it has taken the Occupational Safety and Health Administration (OSHA) so long to adequately regulate it," said Peter Lurie, deputy director of Public Citizen's Health Research Group.

"The results of this study were first presented publicly five years ago, yet the EPA and Johns Hopkins permitted the results to remain unpublished even as hundreds of workers unnecessarily contracted and died from lung cancer," Lurie said.

Public Citizen and workers groups have been pressing for OSHA's exposure limit for hexavalent chromium to be lowered from the present 100 micrograms per cubic meter (ug/m3) to 0.5 ug/m3. The chromium industry has insisted that no regulation take place until the present study was published.

The study is scheduled to be published in the August issue of the American Journal of Industrial Medicine.

OSHA has pledged to issue a proposed regulation for the chemical by June 2001.