The National Institute for Occupational Safety and Health (NIOSH) recently posted information on its Web site that alerts roofing industry workers to the hazards of respirable silica. The silica issue has come to the forefront in the roofing industry after recent NIOSH testing showed worker exposures exceeded the Occupational Safety and Health Administration's (OSHA's) permissible exposure limit during cutting of concrete and clay roofing materials. (See "Understanding a complex killer," August 2005 issue, page 36.)
The danger with regard to inhaling respirable crystalline silica is a lung disease called silicosis. Respirable silica, the sand portion of cut concrete or clay, enters the lungs and causes inflammation and scarring. The result is reduced lung capacity. Silicosis is an insidious disease—its effects may not become apparent until years after an initial exposure to respirable silica. The lung damage from silicosis is irreversible.
Silicosis is a problem usually associated with workers who do sandblasting, rock drilling and building demolition. According to NIOSH, each year, 200 workers die from the disease. Additionally, NIOSH estimates more than 1 million workers are at risk for developing silicosis each year.