October 16 (HealthDay News) -- Levels of a particular antioxidant rise in people with chronic silicosis and could represent a new treatment approach for the debilitating lung disease, Japanese researchers report.

Silicosis is caused by inhaling silica dust for prolonged periods. Sources of exposure include: mines; foundries; stone, clay and glass manufacturing plants; and sand blasting operations. In the United States, it's believed that more than a million workers have been exposed to silica dust.

If inhaled, silica dust triggers the production of reactive oxygen species, which cause scar tissue to develop in the lungs.

This study found that one antioxidant, called heme oxygenase-1 (HO-1), becomes elevated in chronic silicosis patients. HO-1 also appears to protect against lung damage, slowing disease progression.

This is the first study to show that HO-1 is produced in the lungs of people with chronic silicosis.

The findings were published in the second October issue of the American Journal of Respiratory and Critical Care Medicine.

SOURCE: American Thoracic Society, news release, Oct. 16, 2006