Chapter 2 Fundamentals of Toxicology and Toxicological Chemistry

Assignment #6

Fundamentals of Toxicology and Toxicological Chemistry, summarize in paragraph form.  Type written - Arial 12pt.  Summarize each question in paragraph form.

1. What is a dose-response curve?

2. What is meant by a toxicity rating of less than10^-5?

3. What are the three major subdivisions of the dynamic phase of toxicity, and what happens in each?

4. Characterize the toxic effect of carbon monoxide in the body. Is its effect reversible or irreversible? Does it act on an enzyme system?

5. Distinguish among teratogenesis, mutagenesis, carcinogenesis, and immune system effects. Are there ways in which they are related?

6. As far as environmental toxicants are concerned, compare the relative importance of acute and chronic toxic effects and discuss the difficulties and uncertainties involved in studying each.

7. Exposures to toxicants are classified as to whether they are acute or chronic, as well as local or systemic. These combinations give four possibilities, such as acute local for a single exposure to a toxic substance to a particular part of the body. Using this classification system, characterize each of the following exposures: (A) an acid burn from spilling concentrated nitric acid on a hand; (B) cancer of the cheek at age 30 that began with habitual chewing of tobacco since age 16; (C) cancer of the liver from inhaling vinyl chloride in the workplace; (D) coma resulting from the inhalation of carbon monoxide.

8. A common practice in the U.S. is to use carbon monoxide to keep meat looking fresh. After doing a little research on the Internet, suggest why this might work and what it has to do with toxicological chemistry. Do you think that the practice actually preserves the meat? Do you think that it poses any dangers?

9. After doing a little Internet research on the topic, suggest the relationship of berylliosis to hypersensitivity. Do you think that a genetic component is involved? Which route of beryllium exposure is particularly dangerous?

10. Critique the statement that "xenobiotic substances are those that pose a toxicological hazard, whereas endogenous substances are safe."

11. After doing some research on jaundice, suggest which organ is most likely to be damaged by a toxicant that causes jaundice.

12. Exposure to vinyl chloride is known to cause a specific kind of liver cancer in humans.  After doing some internet research on the subject, explain the statement that vinyl chloride is a xenobiotic compound and a protoxicant.

13.   Classify each of the following toxic effects regarding whether or not exposure to the toxic agent is acute or chronic and whether they are local or systemic

A. Death from inhaling carbon monoxide from an automobile left running in a garage.

B. Cancer of the mouth from long-term use of chewing tobacco.

C. Peripheral neuropathy from working in an atmosphere contaminated with hydrocarbon solvents over many decades.

D. A lesion caused by spilling concentrated nitric acid on the skin.

14. Suggest why the bladder is the organ that is likely to develop cancer from  exposure to aromatic amines

15. Though highly toxic, botulinus toxin has some important pharmaceutical and cosmetic applications.  After a search of the internet explain what some of these are.