Chronic toxicity is a property of a substance that has toxic effects on a living organism, when that organism is exposed to the substance continuously or repeatedly. Compared with acute toxicity

Acute toxicity

Acute toxicity describes the adverse effects of a substance that result either from a single exposure or from multiple exposures in a short space of time...

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Two distinct situations need to be considered:

• Prolonged exposure to a substance

For example if a person drinks too much alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

 on a regular basis then their health may suffer as a result. The alcohol does not have a long biological halflife but it is supplied on a regular basis to the body of the person.

• Prolonged internal exposure because a substance remains in the body for a long time

For example if a person were to ingest radium

Radium

Radium is a chemical element with atomic number 88, represented by the symbol Ra. Radium is an almost pure-white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226,...

 much of it would be absorbed into the bones where it would exert a harmful effect on a person's health. The radium might cause a disturbance in the blood cell-forming part of the bone (bone marrow

Bone marrow

Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...

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