A-E

A-E

absolute lethal concentration

(LC ₁₀₀)

Lowest concentration of a substance in an environmental medium which kills 100%

of test organisms or species under defined conditions.

Note	This value is dependent on the number of organisms used in its assessment.

absolute lethal dose

(LD ₁₀₀)

Lowest amount of a substance which kills 100% of test animals under defined

conditions.

Note	This value is dependent on the number of organisms used in its assessment.

absorbed dose

(of a substance)

Amount (of a substance) taken up by an organism or into organs or tissues of interest.

See also absorption, systemic.

See also internal dose.

absorbed dose

(of radiation)

Energy imparted to a unit mass of matter by ionizing radiation divided by the mass

of the absorbing volume.

absorption

(in biology)

Penetration of a substance into an organism by various processes, some specialised, some involving expenditure of energy (active transport), some involving a carrier system, and others involving passive movement down an electrochemical gradient. Note: In mammals absorption is usually through the respiratory tract, gastrointestinal tract, or skin.

absorption

(of radiation)

Phenomenon in which radiation transfers some or all of its energy to matter, which

it traverses.

absorption, systemic

Uptake to the blood and transport via the blood of a substance to an organ or compartment in the body distant from the site of absorption.

absorption coefficient

(in biology)

Ratio of the absorbed amount (uptake) of a substance to the administered amount (intake).

Note

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