FIGURE 5- 1 Exposure routes for chemical agents in hazardous waste.

FIGURE 5-2 Overview of absorption, distribution, storage, transformation, and elimination of a toxic substance in the human body.

FIGURE 5-3 Types of doses for dermal contact with contaminated soil.

FIGURE 5-4 Correlation of atmospheric benzene concentrations with urinary phenol levels in workers in a rubber coating plant.

FIGURE 5-5 Effect of dose fractionalization on accumulation of a toxic compound.

FIGURE 5-6 Sequence of events leading up to a toxic response.

FIGURE 5-7 Representative cellular targets for toxic action.

FIGURE 5-8 Lock-and-key model for toxic action.

FIGURE 5-9 Example of compounds with identical molecular formula but different toxicity.

FIGURE 5-10 Inhibition of enzyme acetylcholinesterase (AChE) by organophosphorus.

FIGURE 5-11 Dose-response relationship (dose versus mortality).

FIGURE 5-12 Dose-response relationship for erythrocyte protoporphyrin (EP) in blood as a function of the blood lead level in subpopulations.

FIGURE 5-13 Effect of EGM on the relative organ weights of testes and prostate.

FIGURE 5-14 Health effects from breathing and/or ingesting lead.

FIGURE 5-15 Health effects from breathing benzene.

FIGURE 5-16 Adequacy of human exposure data on health effects of benzene.

FIGURE 5-17 Adequacy of animal test data on health effects of benzene.

FIGURE 5-18 Location of NOAEL and LOAEL doses with respect to the threshold on a typical dose-response curve.

FIGURE 5-19 Three stages in carcinogenesis.

FIGURE 5-20 Metabolic activation of benzo(a)pyrene.

FIGURE 5-21 Example of a point mutation through base pair substitution.

FIGURE ,3,7,8- tetrachlorodibenzo(p)dioxin.

FIGURE 5-23 Hypothetical dose- response curve for a typical complete carcinogen.

FIGURE 5-24 Extrapolation of dose-response relationship for liver tumors induced by 2- cetylaminofluorene in the low-dose range.

FIGURE 5-25 Toxicological/ecological relevance and time scale of toxic responses for levels of biological organization.

FIGURE 5-26 Idealized plot of dose-responserelationship.

FIGURE 5-27 Graphical interpolation of time- ependent LC50 values for sodium selenite.

FIGURE 5-28 Biomagnification of pesticides in aquatic food chains.

FIGURE 5-29 Possible movement and fate of a contaminant after absorption into the bloodstream of fish.