Question

Define environmental toxicology. Give an example of a study that would be relevant to this field.

Define the terms teratogen, xenobiotic, and carcinogen and provide one example of each.

What is latency? How does the issue of latency challenge environmental researchers who are trying to detect hazards associated with specific exposures?

Answer 1

Environmental toxicology ---- it is a multidisciplinary field of science that conserned with the study of harmful effects of various chemical , physical and biological agents on living organisms .

Ecotoxicology is subdiscipline of environmental toxicology which concerned with studying the harmful effects of toxicants at the population and ecosystem level .

Organisms get exposed to various toxicants like pesticides, insecticides , pollutants , fertilizer which can accumulate in them called as bioaccumulation . this bioaccumulation is harmful for that organism as it effects it's it's cycle and reproductive capacity.

DEFINITION

1) teratogens ---they are the harmful substances which produces physical , functional and developmental defects in human embryo or fetus when pregnant women is exposed to them during period of pregnancy . Example are a) alcohol b) cocaine c)tobbco d) ace inhibitors e) tetracycline f) toxoplasmosis etc are potential teratogens

2) Xenobiotics --- they are defined as chemical substances which are present in organisms that are not naturally produced by or expected to be present in that organism.

It is produced by during various biochemical reactions like pharmacological reaction , toxicity reaction , immunological reaction and in some cancers also

Example are a. Hormone b.pigments c. Flavonoids d. Pesticides .

3) carcinogens -- they are difined as any substance , radiation , radionuclide which promotes carcinogenesis by distroying genetic makeup or by altering metabolic activity . They causes rapid growth and division of cells .

Examples are a. Asbestos b. Nickel c.cadmiun d.radion e .benezene etc

LATENCY --also known as latent period is period between exposure and onset of period of communicability which may be shorter than or longer than incubation period of disease

Latent period is most difficult to identify when exposure occur over a extended period of time ,not at one point of time which challenge environmental researchers who are trying to detect hazardous effect of any exposure .

Example are cigarette smoking , alcohol effect and occupational exposure effect .

Here the exposure doesn't occur at single period of time but over a long extended period of time .

Therefore it is difficult to know exactly when this exposure cause disease or cancer in that person, usually the latest period is used for preventing the disease spread .