| Introduction | |
| Fundamental Concept of Bioavailability | |
| Definition of Bioavailability | |
| Unaltered Form | |
| Systemic Circulation | |
| Relationship Between Extent and Rate of Bioavailability | |
| Extent of Bioavailability | |
| Bioavailability in Health Risk Assessment | |
| Biologically Effective Dose | |
| Internal Dose and Average Daily Internal Dose | |
| External Dose and Average Daily External Dose | |
| Summary | |
| Mechanism of Absorption | |
| Respiratory System | |
| Structure and Function | |
| Rate-Limiting Processes for Gaseous Phase Contaminants | |
| Other Factors Influencing Respiratory Bioavailability for Gases and Vapors | |
| Rate-Limiting Processes for Particulate Phase Contaminants | |
| Other Factors Influencing Respiratory Bioavailability for Aerosols | |
| Gastrointestinal System | |
| Structure and Function | |
| Rate-Limiting Processes | |
| Other Factors Influencing Oral Bioavailability | |
| Skin | |
| Structure and Function | |
| Rate-Limiting Processes | |
| Other Factors Influencing Dermal Bioavailability | |
| Summary | |
| Experimental Methods for Evaluating Bioavailability | |
| General in Vivo Methods | |
| Measurement of Blood Levels | |
| Measurement of the Cumulative Urinary Excretion | |
| Mass-Balance Technique | |
| Measurement of Toxic Response | |
| Specific Methods for the Inhalation Exposure Route | |
| Determination of Deposition Fraction | |
| Mechanical Clearance Fraction | |
| Dissolution Rate | |
| In Vitro Methods: Isolated Perfused Lung | |
| Specific Methods for the Ingestion Exposure Route | |
| Measurement of Fecal Excretion | |
| Measurement of Liver Ratio | |
| Dissolution Testing | |
| Methods Based on the pH Partition Theory | |
| Specific Methods for Dermal Exposure Route | |
| Surface Disappearance | |
| In Vitro Methods: Biological Membrane Models; Artificial Membrane Models | |
| Summary | |
| Exposure Routes and Bioavailability Factors for Selected Contaminants* | |
| Arsenic | |
| Cadmium | |
| Chromium and Chromium Compounds | |
| Copper | |
| Mercury | |
| Lead | |
| 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) | |
| Polynuclear Aromatic Hydrocarbons (PAHs) | |
| Benzene | |
| Toluene | |
| Polychlorinated Phenols | |
| Phenol | |
| Aniline | |
| Bioavailability of Xenobiotics from Contaminated Sites | |
| Identification of Exposure Routes | |
| Reliability and Validity of the Bioavailability Factors | |
| Choice of Experimental Methods | |
| Analytical Capabilities | |
| Species Differences | |
| Mixtures and Vehicles | |
| Mechanism of Toxicity | |
| Chemical Forms | |
| Exposure Duration and Frequency | |
| Priority Needs for Further Research | |
| Considerations for Applying Bioavailability to Health Risk Assessment | |
| Metals | |
| Organic Xenobiotics | |
| Other Application Considerations | |
| Risk Management Considerations | |
| References | |
| Glossary of Terms | |
| Index | |
| *For each of the contaminants in this section, the following is provided: | |
| Exposure Routes and Receptors | |
| Toxicokinetics (Following Absorption) | |
| Bioavailability (Inhalation, Ingestion, Dermal) | |
| Uncertainties | |
| Conclusions | |
| Recommendations |