Poisons

Chronic toxicity

When toxic effects of chemicals develop after a longer period of exposure to smaller concentrations than are required to cause acute poisoning, they are referred to as chronic toxicity. In humans, chronic toxicity may take the form of increased rate of birth defects and spontaneous abortions (miscarriages), cancer, and organ damage. Because of their relatively indeterminate nature and long-term lags in development, chronic toxicities are much more difficult to diagnose than acute toxicities.:

In the home

For children, household chemicals pose the greatest threat for poisoning. Substances such as art supplies; cleaning and laundry products; cosmetics, medications, and vitamin supplements; and garden and automotive chemicals are all potentially hazardous, especially to young children.

In the environment

Many poisonous chemicals—such as metals and other elements—are present naturally in the environment, causing natural "pollution" in areas where minerals containing toxic elements, such as copper, lead, selenium, or arsenic are concentrated. The soil may contaminate plant material in areas, such as the semi-arid regions of the western United States, where the soil contains high concentrations of selenium. This element is absorbed by plants, causing them to become extremely poisonous to cattle that might eat their toxic foliage.

Other naturally occurring toxins are biochemicals that are synthesized by plants and animals as part of their system of defenses. Some of the most toxic chemicals known to science, such as tetrodotoxin, synthesized by the Japanese globe fish (Sphdroides rubripes), occur in nature. Other examples of deadly biochemicals are snake and bee venoms and mushroom poisons.

See also Lead Poisoning

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Author Info: , Thomson Gale, Detroit, Gale Encyclopedia of Childhood and Adolescence, 1998

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.