1. Environmental Biology for Engineers and Scientists D.A. Vaccari, P.F. Strom, and J.E. Alleman © John Wiley & Sons, 2005 Chapter 17 – The Science of Poisons Chapter 18 – Fate and Transport of Toxins

2. Figure 17-1. (a) Normal hydrolysis of acetocholine by the enzyme acetocholinesterase; (b) reaction of organophosphate pesticides with enzyme; (c) reaction of carbamate pesticides with enzyme. Acetocholine hydrolysis: normal, with organophosphates, with carbamates. [Based on W&B and L&Y]

3. Figure 17-2. Hardness and pH interaction in copper toxicity. [Based on R&P]

4. Figure 18-1. Passive transport across a membrane by molecular diffusion. Partition coefficient is approximately 2.0. Membrane h C = 0 C1 C2 C3 C4 Flux Source Compartment Receptor Compartment

5. Figure 18-2. Illustration of how pH relationships in the stomach and blood plasma facilitate absorption of weak acids such as benzoic acid. [Based on Lu] Membrane Stomach pH 2 Blood pH 7.4 COO - COOH + H + 1 100 1 2512

6. Figure 18-3. Examples of microsomal oxidation biotransformation reactions.

7. Figure 18-3. More microsomal oxidation biotransformation reactions.

8. Figure 18-4. Examples of biotransformation reduction reactions. Reduction

9. Figure 18-5. Examples of hydrolysis biotransformation reactions. a) Aliphatic ester b) Organophosphate ester c) Peptide bond

10. d) Epoxide Figure 18-5. More hydrolysis biotransformation reactions.

11. Figure 18-6. Examples of conjugation (phase II) biotransformation reactions.

12. Figure 18-6. More conjugation (phase II) biotransformation reactions.

13. Figure 18-7. Examples of glutathione conjugation (phase II) biotransformation reactions.

14. Figure 18-8. Schematic of a one-compartment model, and a plot of uptake and depuration of a contaminant in the case of a fixed environmental concentration. [Based on C&M]

15. Figure 18-9. Biomagnification of two organochlorine pesticides in aquatic food chains. [From LaGrega, et al] Water 0.02 ppm Plankton 5.3 ppm; x265 Small fish 10.0 ppm; x500 Predator fish 1,700 ppm; x85,000 Pesticide: DDD Pesticide: Toxaphene Water 0.2 ppm Planktonic crustaceans 73 ppm; x365 Goldfish 200 ppm; x1,000 Pelican 1,700 ppm; x8,500

16. Figure 18-10. Multi-compartment model of an animal. Absorption Excretion Storage Bile Liver Lung GI tract Dermal or eye InhalationIngestion ExhalationFeces Bones and tissues Organs Fat Kidneys BladderLung SecretionsUrine Blood and Lymph Glands Distribution

17. Figure 18-11. Typical concentration-time plot for two-compartment model. The systemic compartment typically represents blood concentration. The peripheral compartment can represent another tissue or organ, such as the brain or muscle. C and V are the concentration and volume, respectively, of the compartments. In this simulation k e, K p, and V 2 = 1.0, and V 1 = 3.0.

18. Figure 18-12. Concentration-time plot for continuous and intermittent exposure.

19. Figure 18-13. The effect of differing pharmacokinetics on time course of concentration in an organism. k e, Kp, and V 1 = 1.0, and V 1 = 1.0 or 0.1 as indicated. [Based on Lu]