Introduction to Toxicology

EV 460/660 & BI 460/660

Fall 2014

Review for Fourth Exam – Part 1Environmental Toxicology

1.Briefly define the areas of study and concern of environmental toxicology.

2.Historically, what have been the properties of chemicals of major environmental concern?

3.Concisely define or explain the following terms: environmental persistence, abiotic degradation, biotic degradation, bioaccumulation, and biomagnification.

4.Name and briefly describe the two major processes of abiotic degradation of environmental chemicals.

5.What groups of organisms are primarily responsible for biotic degradation? What types of reactions occur in biotic degradation of environmental chemicals?

6.How does lipid solubility affect the potential for bioaccumulation and biomagnification of an environmental chemical? Describe reasons for bioaccumulation and biomagnification of chemicals in aquatic and marine ecosystems. How can bioaccumulation of lipophilic toxicants result in delayed onset toxicity?

7.Describe similarities between toxicokinetics in individual organism and toxicokinetics in the environment with regard to: organismal absorption vs. environmental source, organismal transport and distribution vs. environmental transport and distribution, and organismal transformation reactions vs. environmental transformation reactions.

8.Describe differences between toxicokinetics in individual organisms and toxicokinetics in the environment.

9.Define the term “mass emission rate”. Give the simple equation (with appropriate units) for mass emission rate.

10.Distinguish between point sources and non-point sources of emissions. Give specific examples of each. Contrast these two types of emission sources with regard to quantification of mass emission rates, monitoring, regulation, and control, and states of regulatory policy/law, and pollution control technologies.

11.Distinguish between advection and diffusion transport of toxicants in the environment.

12.Distinguish between homogeneous and heterogeneous advection and give examples of each.

13.Distinguish between diffusion within a phase or medium and diffusion between phases or media. Name the three types of interfaces between media. What determines diffusive transport between media?

14.What factors affect air-water partitioning? What types of chemicals will tend to pass from water into air vs. from air into water?

15.What factors affect lipid-water partitioning? What is the particular relevance of this partitioning to biological systems?

16.What factors affect particle-water partitioning?

17.Distinguish between reversible and irreversible environmental transformation processes. Give several examples of each type of reaction. Which type of transformation reaction more commonly involves metabolism by organisms?