An updated edition of the foundational guide to environmental risk analysis
Environmental risk analysis is a systematic process essential for the evaluation, management, and communication of the human health risk posed by the release of contaminants to the environment. Performed correctly, risk analysis is an essential tool in the protection of the public from the health hazards posed by chemical and radioactive contaminants. Cultivating the quantitative skills required to perform risk analysis competently is a critical need.
Quantitative Environmental Risk Analysis for Human Health meets this need with a thorough, comprehensive coverage of the fundamental knowledge necessary to assess environmental impacts on human health. It introduces readers to a robust methodology for analyzing environmental risk, as well as to the fundamental principles of uncertainty analysis and the pertinent environmental regulations. Now updated to reflect the latest research and new cutting-edge methodologies, this is an essential contribution to the practice of environmental risk analysis.
Readers of the second edition of Quantitative Environmental Risk Analysis for Human Health will also find:
- Detailed treatment of source and release characterization, contaminant migration, exposure assessment, and more - New coverage of computer-based analytical methods - A new chapter of case studies providing actual, real-world examples of environmental risk assessments
Quantitative Environmental Risk Analysis for Human Health is must-have for graduate and advanced undergraduate students in civil engineering, environmental engineering, and environmental science, as well as for risk analysis practitioners in industry, environmental consultants, and regulators.
Table of Contents
List of Variables with Common Example Units xvii
Preface to Second Edition xxvii
Preface to First Edition xxix
1 Introduction 1
1.1 Risk Analysis 2
1.2 Risk 4
1.3 Contaminants in the Environment 8
1.4 Uses of Environmental Risk Assessment 9
1.5 Risk Assessment Process 13
1.5.1 Problem Statement 13
1.5.2 System Description 14
1.5.3 Risk Calculation 14
1.5.4 Integration and Iteration 18
References 19
Additional Reading 20
Problems 21
2 Fundamental Aspects of Environmental Modeling 23
2.1 Introduction 23
2.2 Modeling Process 24
2.2.1 Model Development 24
2.2.2 Modeling Assurance 28
2.2.3 Environmental Modeling in Phases 30
2.3 Physical and Mathematical Basis for Risk Assessment Models 31
2.3.1 Mass Balances 31
2.3.2 Simple Models 40
2.4 Contaminant Transport Equation 47
2.4.1 Transport Processes 48
2.4.2 Derivation of the Contaminant Transport Equation 49
2.4.3 Zero-dimensional Solutions of the Contaminant Transport Equation 52
References 58
Additional Reading 59
Problems 59
3 Release Assessment 64
3.1 Introduction 64
3.2 Conceptual Model 65
3.3 Contaminant Identification 66
3.4 Emission-Rate Quantification 72
3.4.1 Release Probability 74
3.4.2 Contaminant Emission Rate 79
References 83
Additional Reading 84
Problems 84
4 Environmental Transport Theory 87
4.1 Introduction 87
4.2 One-Dimensional Solutions of the Contaminant Transport Equation 89
4.2.1 One-dimensional Advection 89
4.2.2 One-dimensional Advection and Dispersion 95
4.3 Three-Dimensional Contaminant Transport 99
4.4 Advanced Solution Methods 100
4.4.1 Numerical Techniques 100
4.4.2 Superposition Integral 101
References 103
Additional Reading 104
Problems 104
5 Surface Water Transport 107
5.1 Introduction 107
5.2 Types of Surface Water Bodies 109
5.2.1 Rivers and Streams 109
5.2.2 Lakes 111
5.2.3 Reservoirs on Rivers 111
5.2.4 Estuaries 111
5.2.5 Oceans 111
5.3 Sorption 112
5.3.1 Distribution Coefficient 112
5.3.2 Fraction Sorbed 116
5.3.3 Inclusion of Sorption in Transport Models 117
5.4 Transport Modeling 119
5.4.1 Lakes 119
5.4.2 Rivers and Streams 123
References 128
Additional Reading 129
Problems 129
6 Groundwater Transport 132
6.1 Introduction 132
6.2 Subsurface Characterization 134
6.3 Saturated Flow in Porous Media 135
6.3.1 Groundwater Speed and Direction 135
6.3.2 Porosity and Hydraulic Conductivity 138
6.3.3 Dispersion 138
6.4 Sorption 143
6.5 Subsurface Contaminant Transport Modeling 144
6.5.1 Linear Equilibrium Model of Subsurface Contaminant Transport 144
6.5.2 Saturated-Zone Transport Solutions 148
6.6 Other Considerations in Groundwater Transport 153
6.6.1 Vadose Zone Transport 153
6.6.2 Colloidal Transport 155
6.6.3 Transformations 155
6.6.4 NonAqueous-Phase Liquids 156
References 158
Additional Reading 159
Problems 159
7 Atmospheric Transport 163
7.1 Introduction 163
7.2 Atmospheric Dispersion 164
7.3 Atmospheric Transport Models 168
7.3.1 Constant Emission Rate: Gaussian Plume Model 168
7.3.2 Long-Term Averages 175
7.3.3 Infinite Line Source 179
7.3.4 Instantaneous Emission: Gaussian Puff Model 179
7.4 Other Considerations 180
7.4.1 Effective Release Height and Plume Rise 180
7.4.2 Building Wake 181
7.4.3 Release with Inversion Aloft 182
7.4.4 Nonconservative Processes 184
References 186
Additional Reading 187
Problems 187
8 Food Chain Transport 191
8.1 Introduction 191
8.2 Concentration in Soil 195
8.2.1 Conceptual Model 195
8.2.2 Atmospheric Deposition 197
8.2.3 Irrigation Deposition 197
8.2.4 Atmospheric Resuspension 198
8.3 Concentration in Vegetation 199
8.4 Concentration in Animals 204
References 206
Additional Reading 207
Problems 207
9 Exposure Assessment 210
9.1 Introduction 210
9.2 Dose 212
9.2.1 Chemical Dose 212
9.2.2 Radiological Dose 214
9.3 Contaminant Intake 215
9.3.1 Inhalation 216
9.3.2 Ingestion 216
9.3.3 Dermal Absorption 218
9.4 Dose Calculations 220
9.4.1 Chemical Dose Calculations 220
9.4.2 Radiological Dose Calculations 222
References 227
Additional Reading 228
Problems 228
10 Basic Human Toxicology 230
10.1 Introduction 230
10.2 Fundamentals of Anatomy and Physiology 231
10.2.1 Cellular Anatomy and Physiology 232
10.2.2 Cellular Mechanisms of Toxicity 237
10.2.3 Major Organ Systems 239
10.3 Mechanisms and Effects of Toxicity 250
10.3.1 Systemic Effects 250
10.3.2 Carcinogenic Effects 252
10.3.3 Teratogenic Effects 256
10.3.4 Hereditary Effects 258
References 259
Problems 261
11 Dose-Response and Risk Characterization 263
11.1 Introduction 263
11.2 Biological Basis of Dose-Response Modeling 264
11.3 Elements of Quantitative Dose-Response Analysis 266
11.3.1 Factors Affecting Toxicity 266
11.3.2 Quantification of Responses 272
11.3.3 Sources of Dose-Response Data 274
11.4 Dose-Response Modeling 279
11.4.1 Animal-to-Human Extrapolation 280
11.4.2 Dose-response models and high- to low-dose extrapolation 283
11.5 Risk Characterization 287
11.5.1 Margin of Exposure 287
11.5.2 Cancer Slope Factors and Unit Risk 289
11.6 Regulatory Implementation 290
11.6.1 The Benchmark Dose (BMD) Approach 291
11.6.2 Deterministic (Noncancer) Endpoints 293
11.6.3 Stochastic (Non-threshold) Endpoints 299
References 305
Additional Reading 308
Problems 308
12 Uncertainty and Sensitivity Analyses 311
12.1 Introduction 311
12.2 Types and Sources of Uncertainty 312
12.2.1 Qualitative and Quantitative Considerations 312
12.2.2 Sources of Uncertainty 313
12.2.3 Types of Uncertainty 314
12.3 Statistics Fundamentals 317
12.3.1 Random Variables and Distribution Functions 317
12.3.2 Characterization of PDFs 319
12.3.3 Determination of Distributions 320
12.4 Uncertainty Propagation 324
12.4.1 Sensitivity Analysis 325
12.4.2 Methods for Uncertainty Propagation 327
References 340
Problems 343
13 Screening and Computational Resources 348
13.1 Introduction 348
13.2 Screening Tools 349
13.2.1 COMPLY/COMPLY-R 349
13.2.2 DandD 350
13.2.3 Groundwater Transport Calculator 350
13.2.4 RSL and RML 350
13.2.5 RAIS PRG Calculators 351
13.2.6 RAIS Risk Calculators 351
13.2.7 SERAFM 351
13.3 Surface Water Transport 352
13.3.1 BASINS 352
13.3.2 EFDC 352
13.3.3 LADTAP II 353
13.3.4 QUAL2K 353
13.3.5 WASP 354
13.3.6 SMS 13 354
13.4 Groundwater Transport 354
13.4.1 3DFEMWATER/3DLEWASTE 354
13.4.2 EPACMTP 355
13.4.3 GMS 355
13.4.4 HELP 355
13.4.5 MODFLOW 6 356
13.4.6 PORFLOW 356
13.4.7 STOMP 357
13.4.8 TOUGHREACT 357
13.5 Atmospheric Transport 357
13.5.1 AERMOD 358
13.5.2 ALOHA 358
13.5.3 CTDMPLUS 359
13.5.4 HOTSPOT 359
13.5.5 HYSPLIT 359
13.5.6 PAVAN 360
13.5.7 RASCAL 360
13.5.8 XOQDOQ 360
13.6 Food Chain Transport 361
13.6.1 BASS 361
13.6.2 CAP-88 PC 361
13.6.3 GASPAR II 362
13.6.4 MILDOS 4 362
13.7 Transport, Exposure, and Consequence Assessment Tools 363
13.7.1 CalTOX 363
13.7.2 FRAMES-2.0 363
13.7.3 GENII 364
13.7.4 GOLDSIM 364
13.7.5 MEPAS 364
13.7.6 RESRAD 365
13.7.7 Risk Analyst 366
13.8 Geochemical Speciation Modeling 367
13.8.1 GWB 367
13.8.2 MINEQL+ 368
13.8.3 MINTEQA2/VISUAL MINTEQ 368
13.8.4 PHREEQC 368
13.9 Uncertainty 369
13.10 Other Useful Computational Resources 370
13.10.1 RESRAD-BUILD 370
13.10.2 SADA 370
13.10.3 VSP 370
13.10.4 BMDS 370
References 370
14 Case Studies 376
14.1 Introduction 376
14.2 PFAS 376
14.2.1 Background 377
14.2.2 Wilbur Earl Tenant’s Farm (EPA 2001, Bilott 2019) 377
14.2.3 Parkersburg and EPA (EPA 2001, Bilott 2019) 378
14.2.4 Epilogue 379
14.3 Arsenic in Drinking Water 380
14.3.1 Introduction 380
14.3.2 Risk Calculation 381
14.3.3 Risk Assessment 381
14.4 MCHM 382
14.4.1 Background 382
14.4.2 Calculation of MCHM Concentration 383
14.4.3 Epilogue 386
14.5 Releases from Rocky Flats 387
14.5.1 Introduction 388
14.5.2 1957 Plutonium Fire Basic Risk Assessment 388
14.5.3 Rocky Flats Comprehensive Risk Assessment 390
14.5.4 Comparisons for 1957 Plutonium Fire 391
14.5.5 Epilogue 393
References 393
Problems 395
15 Ethics, Stakeholder Involvement, and Risk Communication 396
15.1 Introduction 396
15.2 Ethics 397
15.2.1 Overview 397
15.2.2 Ethical Theories 397
15.2.3 Environmental Ethics 398
15.3 Stakeholder Involvement 400
15.3.1 Motivation 400
15.3.2 Potential Benefits and Detriments 401
15.3.3 Scope of Stakeholder Involvement 403
15.3.4 Legal Basis and Requirements 405
15.3.5 Methods and Approaches 405
15.4 Risk Communication 410
15.4.1 Scientific Basis 411
15.4.2 Practical Considerations 416
15.4.3 Unresolved Issues 417
References 418
Problems 422
16 Environmental Risk Management 423
16.1 Introduction 423
16.2 Risk Management Process 423
16.3 Risk Management Methods 424
16.3.1 Approaches to Risk Management 424
16.3.2 Fundamentals of Decision Analysis 426
16.3.3 Methods for Decision Analysis Under Certainty 433
16.3.4 Methods for Decision Analysis Under Risk 438
References 441
Problems 442
17 Environmental Laws and Regulations 444
17.1 Introduction 444
17.2 General Legal and Regulatory Structure for Environmental Protection 444
17.2.1 U.S. Governmental Structure 444
17.2.2 Regulatory Hierarchy 445
17.3 Major Federal Environmental Laws and Regulations 446
17.3.1 National Environmental Policy Act 447
17.3.2 CERCLA and SARA 449
17.3.3 Resource Conservation and Recovery Act 452
17.3.4 Toxic Substances Control Act 453
17.3.5 Clean Air Act 454
17.3.6 Clean Water Act 456
17.4 CERCLA Process 457
17.4.1 Remedial Actions Under CERCLA 457
17.4.2 Risk Assessment in the RI/FS Process 458
17.5 Additional Regulations 459
References 460
Problems 461
Appendix A Mathematical Tools 462
A 1 Special Functions 462
A.1 1 Dirac Delta Function 462
A.1 2 Heaviside Unit Step Function 463
A.1 3 Error Function and Complementary Error Function 463
A.1 4 Gamma Function 464
A 2 Laplace Transforms 465
A.2 1 Definitions and Notation 465
A.2 2 Basic Transforms and Properties 466
A.2 3 Solution of Differential Equations with Laplace Transforms 467
A 3 Exact Solutions to the One-Dimensional Contaminant Transport Equation 470
References 473
Additional Reading 474
Appendix B Degradation and Decay Parameters 475
Index 477
