Contents
xi
9.1.2. Organism Adiposity and Internal Distribution
of Contaminants ... . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 205
9.1.3. Nonlipid Factors Affecting Internal Distributions ..... 206
9.2. Prediction of Bioconcentration and Bioaccumulation ........ 207
9.2.1. Bioconcentration ............................... 207
9.2.2. Bioaccumulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 208
9.3. Factors Affecting Prediction. . . . . . . . . . . . . . . . . . . . . . . . . . .. 209
9.3.1. Methods for Measuring Lipid Content .............. 209
9.3.2. Lipid Composition and Bioaccumulation ............ 210
9.4. Mimicking Bioconcentration with Semipermeable
Membrane Devices ................................... 211
9.5. Toxicity and the Role of Lipid. . . . . . . . . . . . . . . . . . . . . . . . .. 213
9.5.1. Release of Sequestered Contaminant
During Metabolism ............................. 213
9.5.2. Lipids and Membrane Narcosis. . . . . . . . . . . . . . . . . . .. 214
9.5.3. Effect of Toxins on Lipid Metabolism and Function ... 214
9.6. Relevance of Food Chain Transfer to Bioaccumulation ...... 215
9.6.1. Relevance of Trophic Transfer to Bioaccumulation .... 215
9.6.2. Role of Lipids in Food Chain Accumulation ......... 216
9.6.2.1. Fugacity Model ......................... 216
9.6.2.2. Mechanism for Trophic Transfer. . . . . . . . . . .. 218
9.6.3. Factors Affecting Trophic Transfer. . . . . . . . . . . . . . . .. 219
9.6.3.1. Assimilation Efficiency ................... 219
9.6.3.2. Miscellaneous Factors Affecting
Assimilation ............................ 220
9.7. Biomagnification and Organism Lipids ................... 220
9.7.1. Is Biomagnification Real? ........................ 220
9.7.2. A Lipid-Based Model for Biomagnification .... . . . . .. 221
9.7.3. Current Issues in Biomagnification and Relationship
to Lipids ...................................... 223
9.8. Lipids and Transgenerational Transfer
of Contaminants ..................................... 224
9.9. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 226
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 226
10. Lipids in Water-Surface Microlayers and Foams . . . . . . . . . . . . . . . .. 235
Guillermo E. Napolitano and Daniel S. Cicerone
10.1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 235
10.2. Basic Physicochemistry of Surface Microlayers ............ 236
10.3. Basic Structure of Foams .............................. 240
10.4. Sampling Techniques ................................. 242
10.5. Physicochemical Processes at the Surface Microlayers . . . . . .. 245
10.6. Lipids in the Water-Surface Microlayers and Foams. . . . . . . .. 247
10.6.1. Total Lipids and Major Lipid Classes .............. 247
10.6.2. Fatty Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 251
10.7. Research Needs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 253