Hazards of Silica and Health Effects of Silicosis

Occupational exposures to respirable crystalline silica occur in a variety of industries and occupations because of its extremely common natural occurrence and the wide uses of materials and products that contain it. At least 1.7 million U.S. workers are potentially exposed to respirable crystalline silica [NIOSH 1991], and many are exposed to concentrations that exceed limits defined by current regulations and standards.

Silicosis, usually a nodular pulmonary fibrosis, is the disease most associated with exposure to respirable crystalline silica. Although the reported mortality associated with silicosis has declined over the past several decades, many silicosis associated deaths still occur (nearly 300 deaths were reported each year during the period 1992-1995) [NIOSH 1996a; Althouse 1998]. In addition, the number of silicosis associated deaths among persons aged 15 to 44 has not declined substantially [CDC 1998a,b]. An unknown number of workers also continue to die from silica-related diseases such as pulmonary tuberculosis (TB), lung cancer, and scleroderma. The number of cases of silicosis and silica-related diseases in the United States today is unknown.

Source: http://www.cdc.gov/niosh/docs/2002-129/02-129a.html

Engineering Controls for Silica in Construction

As per NIOSH - Construction workers may be exposed to hazardous dust containing silica during construction tasks, including tuckpointing brick, grinding concrete, breaking concrete pavement with a jackhammer, and cutting block and brick. The National Institute for Occupational Safety and Health (NIOSH) found that exposure could be reduced through the use of engineering controls, including the use of local exhaust ventilation to capture dust at its source and the use of water sprays to suppress dust where it is produced. These pages provide information about those controls and utilize video-exposure monitoring clips to demonstrate their effectiveness.

For more information go to http://origin.cdc.gov/niosh/topics/silica/constructionControlMain.html

NIOSH Engages The National Academies' Institute of Medicine to review Draft Bulletin on Asbestos Fibers

NIOSH has engaged The National Academies' Institute of Medicine to review the draft NIOSH Current Intelligence Bulletin: "Asbestos Fibers and other Elongated Mineral Particles: State of the Science and Roadmap for Research." The June, 2008, version of the draft Current Intelligence Bulletin, and public comments can be found on the NIOSH website at: http://www.cdc.gov/niosh/docket/NIOSHdocket0099A.html. NIOSH’s responses to the public comments and the version of the draft Current Intelligence Bulletin which will be reviewed by the National Academies will be posted on the NIOSH website as soon as they are available, and an updated link will be provided on this web page. The purpose of the National Academies review is to assess the technical quality of the draft document, its scope and the methods used to produce its findings. The National Academies will also assess the likelihood that the program of research envisioned in the draft document will address the most significant scientific issues in the areas of toxicity, occupational exposures, epidemiology, and sampling/analytical methods. It is anticipated that the review will be completed fall, 2009.

The National Academies has established a page on its web site where it will post information about this study: http://www8.nationalacademies.org/cp/projectview.aspx?key=48990.

Source: http://www.cdc.gov/niosh/topics/asbestos/