Researchers Suggest Re-evaluating Definition of Asbestos

By Wade Rawlins
The case of a Michigan school librarian suggests that the definition of asbestos should be broadened, researchers say. In a paper published in the July issue of the International Journal of Occupational and Environmental Health, Dr. Michael R. Harbut and colleagues report on treating a 55-year-old woman who suffers from a stabbing chest pain, has scar tissue on her lungs and other symptoms that meet the classic definition of asbestosis. A scarring of the lungs, asbestosis is typically associated with inhaling asbestos fibers.

The woman, whose name the researchers withheld for medical privacy, has been treated at the National Center for Vermiculite and Asbestos-Related Cancers at Karmanos Cancer Institute at Wayne State University in Detroit, Michigan.

She has experienced pain in the right side of her chest for years. It began as soreness and has progressed to a knife-like pain. She had begun requiring narcotics to handle the pain in recent years. She continues to work as a school librarian in the taconite mining region of Michigan.

The researchers say the most likely cause of the woman’s ailments was dust from taconite mining that her father brought home on his clothes from the mine, when she was a child. He worked as a miner from 1962 to 1969.

Taconite is a rock rich in silica that is used in the production of steel and as a road-patch material. It is mined in Michigan and Minnesota.

The United States government doesn’t classify taconite as asbestos or asbestiform material. But it has been associated with asbestos-related diseases.

“The identification of a material which has not been categorized as asbestos, but causes a disease consistent with asbestosis, requires a reevaluation of the definition of asbestos,” said Mark Harbut, M.D., co-director of the National Center for Vermiculite and Asbestos-Related Cancers and his colleagues. “This is especially important within the context of legislative efforts to prohibit the use of asbestos.

The researchers say their findings support previous reports that dusts produced by taconite mining can cause the same health problems as other fibers already defined as asbestos.

Currently, the Minnesota Department of Health is conducting a study of the cause of more than 48 cases of mesothelioma linked with mining in northeastern Minnesota.

The case suggests that the definition of asbestos should be broadened, they say.

“The question is logically asked, ‘What is asbestos?’” the researchers write. “The most honest answer is, ‘A fiber which causes asbestosis.’”