Lethal Concentration(50) (LC50)
A calculated concentration of a chemical in air to which exposure for a specific length of time is expected to cause death in 50% of a defined experimental animal population.

Cancer Effect Level (CEL)
The lowest dose of chemical in a study, or group of studies, that produces significant increases in the incidence of cancer (or tumors) between the exposed population and its appropriate control.

Fibrosis
A condition marked by the increase of connective, fibrous tissue.

Amosite
A type of asbestos in the amphibole group; it is also known as brown asbestos.

Hazardous Air Pollutants
Air pollutants that are not covered by ambient air quality standards but which, as defined in the Clean Air Act, may reasonably be expected to cause or contribute to irreversible illness or death. Such pollutants include asbestos, beryllium, mercury, benzene, coke oven emissions, radionuclides, and vinyl chloride.

Laparotomy
Abdominal exploration is a type of surgery where the abdomen is opened (laparotomy) and explored (exploratory laparotomy) for examination and treatment of problems. Might be used in relation to asbestos disease problems.

Actinolite
Actinolite is the intermediate member; when iron is predominant the mineral is ferro-actinolite and when magnesium is predominant, the mineral is tremolite. The iron produces a green color that darkens as the iron content increases. Actinolite may occur in fibrous form (an asbestos). It is not used commercially, but is a common impurity in chrysotile asbestos.

Asbestiform
Possessing the properties of asbestos. Minerals of specific chemical compositions can have asbestiform varieties that are fibrous in nature (e.g., crocidolite and amosite are the asbestiform varieties of the amphibole minerals, reibeckite and grunerite; tremolite and actinolite may be either asbestiform or nonasbestiform)

Pericardial mesothelioma
Pericardial mesothelioma is a highly lethal and fortunately rare cardiac neoplasm

Crocidolite asbestos
One of the six types of asbestos. Crocidolite or "blue asbestos," is found in specialized high temperature applications.