Immunologic Toxicity
The occurrence of adverse effects on the immune system that may result from exposure to environmental agents such as chemicals.

Intermediate Exposure
Exposure to a chemical for a duration of 15-364 days, as specified in the Toxicological Profiles.

Risk Ratio
The ratio of the risk among persons with specific risk factors compared to the risk among persons without risk factors. A risk ratio greater than 1 indicates greater risk of disease in the exposed group compared to the unexposed.

Serpentine
In the asbestos varieties, the brucite and silicate layers bend into tubers that produce the fibers. Chrysotile asbestos is a fibrous member of the serpentine group. "Serpentine" comes from mottled shades of green on massive varieties, suggestive of snake markings.

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

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.

Crocidolite
A type of asbestos in the amphibole group; it is also known as blue asbestos.

Dose-Response Relationship
The quantitative relationship between the amount of exposure to a toxicant and the incidence of the adverse effects.

Minimal Risk Level (MRL)
An estimate of daily human exposure to a hazardous substance that is likely to be without an appreciable risk of adverse noncancer health effects over a specified route and duration of exposure.

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)