Natural mineral fibers: conducting inhalation toxicology studies-part B: development of a nose-only exposure system for repeat-exposure study of Libby amphibole aerosol.

Background: Exposure to asbestos is associated with malignant and nonmalignant respiratory disease. To strengthen the scientific basis for risk assessment on fibers, the National Institute of Environmental Health Sciences (NIEHS) has initiated a series of studies to address fundamental questions on the toxicology of naturally occurring asbestos and related mineral fibers after inhalation exposure. A prototype nose-only exposure system was previously developed and validated.

Natural mineral fibers: conducting inhalation toxicology studies - part A: Libby Amphibole aerosol generation and characterization method development.

Background: Asbestos has been classified as a human carcinogen, and exposure may increase the risk of diseases associated with impaired respiratory function. As the range of health effects and airborne concentrations that result in health effects across asbestos-related natural mineral fiber types are not fully understood, the National Institute of Environmental Health Sciences has established a series of research studies to characterize hazards of natural mineral fibers after inhalation exposure. This paper presents the method development work of this research project.

Characterization and assessment of the potential toxicity/pathogenicity of fibrous glaucophane.

In California, the metamorphic blueschist occurrences within the Franciscan Complex are commonly composed of glaucophane, which can be found with a fibrous habit. Fibrous glaucophane's potential toxicity/pathogenicity has never been determined and it has not been considered by the International Agency for Research on Cancer (IARC) as a potential carcinogen to date. Notwithstanding, outcrops hosting fibrous glaucophane are being excavated today in California for building/construction purposes (see for example the Calaveras Dam Replacement Project - CDRP).