List and provide a brief discussion of the seven categories of toxic responses that a biological system may have.
It is known that a biological system may have different toxic responses which are categorized according to the toxic effect. Moreover, the type of toxicity depends on such factors as age, sex, ability to be absorbed and distribution in the body, metabolism and species. There are seven categories of toxic responses:
- Acute toxicity. This category is related to the immediate toxic responses that any biological system may have. It usually stands for the acute exposure of a single dose. It leads to lethal outcomes in most cases.
- Sub-chronic toxicity. This category results from exposure that is repeated several times. It is a common human exposure type that occurs due to some pharmaceuticals or environmental agents.
- Chronic toxicity. This category stands for the cumulative damage to different organs of the biological system. For example, chronic bronchitis of the smokers, or cirrhosis of alcohol abusers.
- Carcinogenicity. This category refers to a complex abnormal process in cells which leads to cancer.
- Developmental toxicity. This category refers to toxic responses to the developing embryo. It occurs due to the toxicant exposure to the partners before the act of conception. It leads to the death of cells of the developing embryo or fetus.
- Genetic toxicity. The main cause of this type of toxicity is a serious damage to DNA. This process is called mutagenesis. It leads to cancer, or cell death.
- Organ toxicity. This category is related to toxic responses to different organs. It includes blood and cardiovascular toxicity, dermal toxicity, eye toxicity, reproductive toxicity, respiratory toxicity and some other types. (Hodgson, 2004, p.275)
Hodgson, E.(2004) A Textbook of Modern Toxicology. Wiley-Interscience; 3-rd edition.