Public health risk assessment for human exposure to chemicals / by Kofi Asante-Duah.

Format:

Book

Author/Creator:

Asante-Duah, D. Kofi.

Contributor:

Rosengarten Family Fund.

Series:

Environmental pollution (Dordrecht, Netherlands) ; v. 6.

Environmental pollution ; v. 6

Language:

English

Subjects (All):

Health risk assessment.

Environmental toxicology.

Risk Assessment.

Public Health.

Environmental Pollutants.

Environmental Exposure.

Medical Subjects:

Risk Assessment.

Public Health.

Environmental Pollutants.

Environmental Exposure.

Physical Description:

xv, 352 pages : illustrations ; 25 cm.

Place of Publication:

Dordecht ; Boston : Kluwer Academic, [2002]

Summary:

Risks to humans as a consequence of chemical exposures are a complex issue with worldwide implications, especially in our modern societies. The effective management of human exposure to a variety of chemicals present in various sectors of society has indeed become a very important public health policy issue -- and risk assessment promises a systematic way for developing appropriate strategies to aid public health risk management decisions. Risk assessment generally serves as a tool that can be used to organize, structure, and compile scientific information in order to help identify existing hazardous situations or problems, anticipate potential problems, establish priorities, and provide a basis for regulatory controls and/or corrective actions.

In fact, with the control and containment of most infectious conditions and diseases of the past millennium having been achieved in most developed countries, and with the resultant increase in life expectancies, much more attention seems to have shifted to degenerative health problems. Many of the degenerative health conditions have been linked to thousands of chemicals regularly encountered in human living and occupational/work environments. It is important, therefore, that human health risk assessments are undertaken on a consistent basis, in order to determine the potential impacts of the target chemicals on public health.

This book provides a concise, yet comprehensive overview of the many facets/aspects relating to human health risk assessments in relation to chemical exposure problems. It presents some very important tools and methodologies that can be used to address chemical exposure and public health risk management problems in a consistent, efficient, and cost-effective way. Overall the book represents a collection and synthesis of the principal elements of the risk assessment process that pertain to human exposures to chemicals in the human living and work environments. It offers an understanding of the scientific basis of risk assessment and its applications to public health policy decisions.

The subject matter of this book should be of interest to many a professional encountering risk assessment in relation to environmental contamination and public health risk management programs -- especially public and occupational health practitioners; environmental consultants; environmental attorneys; public policy analysts; and various health, environmental, and consumer advocacy interest groups. The book is also expected to serve as a useful educational and training resource for both students and professionals in the health-related and environmental fields, who have to deal with human exposures to chemicals, public health risk assessment issues, and/or environmental health management problems.

Contents:

1.1. Coming to Terms with the Several Chemicals in Modern Society 2

1.2. The Nature of Chemical Hazards and Human Response from Exposure to Chemical Substances 7

1.2.1. Classification of Chemical Toxicity 8

1.2.2. Factors Influencing Chemical Toxicity to Humans and Human Response to Chemical Toxicants 9

1.2.3. Distribution and Storage of Toxicants in the Human Body 10

1.2.4. Scope of Chemical Hazard Problems: Lead Exposures as an Example 11

1.3. 'The Dose Makes the Poison'

So, What Dose is Safe Enough? 15

1.4. Managing the Chemical Exposure Problem: The Need for Public Health Risk Assessment 16

Chapter 2 Human Exposure to Chemicals 19

2.1. An Overview of Human Contact Sites and Target Organs Most Susceptible to Chemical Exposures 19

2.1.1. Fundamentals of Human Physiology 20

2.1.2. Target Organ Toxicity 24

2.2. General Types of Human Exposures 25

2.3. The Nature of Chemical Exposure Problems 29

2.3.1. Human Exposures to Airborne Chemical Toxicants 30

2.3.2. Water Pollution Problems and Human Exposures to Chemicals in Water 31

2.3.3. Contaminated Soil Problems and Human Exposures to Chemicals on Land 32

2.3.4. Human Exposures to Chemicals in Foods 33

2.4. Public Health and Socio-Economic Implications of Chemical Exposure Problems 34

2.4.1. The General Nature of Human Health Effects from Chemical Exposures 38

2.5. Assessing Public Health Risks 40

Chapter 3 Principles and Concepts in Risk Assessment 43

3.1. Fundamental Principles of Chemical Hazard, Exposure, and Risk Assessments 43

3.1.1. The Nature of Chemical Hazard, Exposure, and Risk 44

3.1.2. Basis for Measuring Risks 46

3.1.3. What is Risk Assessment? 48

3.1.4. The Nature of Risk Assessments 49

3.1.5. Recognition of Uncertainty as an Integral Component of Risk Assessments 50

3.2. Fundamental Concepts in Risk Assessment Practice 51

3.2.1. Qualitative versus Quantitative Risk Assessments 51

3.2.2. Conservatisms in Risk Assessments 52

3.2.3. Individual versus Group Risks 53

3.2.4. Consideration of Risk Perception Issues 54

3.3. Risk Acceptability and Risk Tolerance Criteria 55

3.3.1. The de Minimis or 'Acceptable' Risk 56

3.4. General Attributes of Risk Assessment 57

3.4.1. The Purpose 58

3.4.2. The Attributes 59

3.4.3. Risk Assessment versus Risk Management 60

3.5. Risk Assessment as a Diagnostic Tool 61

3.5.1. Baseline Risk Assessments 62

3.5.2. Comparative Risk Assessments 62

3.5.3. Public Health Risk Assessments 64

3.5.4. Risk Assessment Implementation Strategy 67

3.6. Risk Assessment as an Holistic Tool for Environmental and Public Health Management 68

Chapter 4 Principal Elements of a Public Health Risk Assessment for Chemical Exposure Problems 71

4.1. Characterization of Chemical Exposure Problems 71

4.1.1. Factors Affecting Exposure Characterization 72

4.2. The Risk Assessment Process 73

4.2.1. Hazard Identification and Accounting 74

4.2.2. Exposure-Response Evaluation 75

4.2.3. Exposure Assessment and Analysis 76

4.2.4. Risk Characterization and Consequence Determination 76

4.3. General Considerations in Public Health Risk Assessments 77

4.3.1. Determining Exposure-related Health Effects 78

4.3.2. Evaluating Factors that Influence Adverse Health Outcome 79

4.4. Human Health Risk Assessment in Practice 83

Chapter 5 Chemical Hazard Determination 87

5.1. Chemical Hazard Identification: Sources of Chemical Hazards 87

5.2. Data Collection and Evaluation Considerations 88

5.2.1. Data Collection and Analysis Strategies 89

5.2.2. Reporting of 'Censored" Laboratory Data 90

5.3. Statistical Evaluation of Chemical Sampling Data 92

5.3.1. Parametric versus Nonparametric Statistics 93

5.3.2. Statistical Evaluation of 'Non-detect' Values 95

5.3.3. Selection of Statistical Averaging Techniques 95

5.4. Estimating Chemical Exposure Point Concentrations from Limited Data 99

5.5. Determination of the Level of Chemical Hazard 102

Chapter 6 Exposure Assessment: Analysis of Human Intake of Chemicals 105

6.1. Fundamental Concepts and Requirements in the Human Exposure Assessment Process 105

6.1.1. Factors Affecting Human Exposure to Chemical Hazards 106

6.1.2. Development of Human Exposure Scenarios 106

6.1.3. Chemical Intake versus Dose 108

6.1.4. Chronic versus Subchronic Exposures 109

6.1.5. Incorporating Chemical Bioavailability Adjustments into Exposure Calculations 109

6.1.6. Chemical Transformation Products in Risk Assessment: Incorporating Chemical Degradation into Exposure Calculations 110

6.2. Human Exposure Quantification: The Exposure Estimation Model 111

6.2.1. Potential Receptor Inhalation Exposures 113

6.2.2. Potential Receptor Ingestion Exposures 116

6.2.3. Potential Receptor Dermal Exposures 121

6.3. Establishing 'Exposure Intake Factors' for Use in the Computation of Chemical Intakes and Doses 122

6.3.1. Illustrative Example for Inhalation Exposures 123

6.3.2. Illustrative Example for Ingestion Exposures 128

6.3.3. Illustrative Example for Dermal Exposures 129

6.4. Receptor Age Adjustments to Human Exposure Factors 132

6.5. Spatial and Temporal Averaging of Chemical Exposure Estimates 132

Chapter 7 Evaluation of Chemical Toxicity 137

7.1. Fundamental Concepts and Principles in Toxicology 137

7.1.1. Mechanisms of Toxicity 138

7.1.2. Categorization of Human Toxic Effects from Chemical Exposures: Carcinogencity vs. Non-carcinogenicity 138

7.1.3. Manifestations of Toxicity 140

7.1.4. Dose-Response Relationships 141

7.2. Carcinogen Classification Systems 144

7.2.1. Weight-of-Evidence Classification 145

7.2.2. Strength-of-Evidence Classification 148

7.3. Evaluation of Chemical Toxicity 149

7.3.1. Hazard Effects Assessment 150

7.3.2. Dose-Response Assessment and Quantification 152

7.4. Determination of Toxicological Parameters for Human Health Risk Assessments 155

7.4.1. Toxicity Parameters for Non-carcinogenic Effects 155

7.4.2. Toxicity Parameters for Carcinogenic Effects 161

7.4.3. The Use of Surrogate Toxicity Parameters 165

7.5. Mechanisms of Action and the Determination of Human Health Hazard Effects 171

Chapter 8 Chemical Risk Characterization and Uncertainty Analyses 173

8.1. Fundamental Issues and Considerations Affecting the Risk Characterization Process 173

8.1.1. Corrections for 'Non-Standard' Population Groups 174

8.1.2. Adjustments for Chemical Absorption: Administered vs.

Absorbed Dose 176

8.1.3. Aggregate Effects of Chemical Mixtures and Multiple Exposures 177

8.1.4. Fundamental Considerations in the Health Assessment of Carcinogens 179

8.2. Carcinogenic Risk Effects: Estimation of Carcinogenic Risks to Human Health 183

8.2.1. Population Excess Cancer Burden 184

8.2.2. Carcinogenic Risk Computations: Illustration of the Processes for Calculating Carcinogenic Risks 186

8.3. Non-cancer Risk Effects: Estimation of Non-carcinogenic Hazards to Human Health 188

8.3.1. Chronic versus Subchronic Non-carcinogenic Effects 190

8.3.2. Non-carcinogenic Hazard Computations: Illustration of the Processes for Calculating Non-carcinogenic Hazards 191

8.4. Risk Presentation 193

8.4.1. Graphical Presentation of the Risk Summary Information 196

8.5. Uncertainty and Variability Issues in Risk Assessment 201

8.5.1. Types and Nature of Variability 201

8.5.2. Types and Nature of Uncertainty 202

8.5.3. Common Sources of Uncertainty in Public Health Endangerment Assessments 203

8.5.4. The Need for Uncertainty and Variability Analyses 206

8.6. Characterization of Data Variability and Uncertainties 206

8.6.1. Qualitative Analysis of Uncertainties 207

8.6.2. Quantitative Analysis of Uncertainties 208

8.7. Presenting and Managing Uncertain Risks: The Role of Sensitivity Analyses 211

Chapter 9 Determination of 'Acceptable' and 'Safe' Levels of Chemical Exposure 213

9.1. Requirements and Criteria for Establishing Risk-Based Chemical Exposure Levels 213

9.1.1. Miscellaneous Methods for Establishing Environmental Quality Goals 214

9.2. Assessing the Safety of Chemicals in Consumer Products 217

9.2.1. Determination of 'Tolerable' Chemical Concentrations 217

9.3. Determination of Risk-Based Chemical Exposure Levels 218

9.3.1. RBCELs for Carcinogenic Constituents 219

9.3.2. RBCELs for Non-carcinogenic Effects of Chemical Constituents 222

9.4. Establishing Risk-Based Cleanup Limits for Contaminated Lands 224

9.4.1. Soil Chemical Limits for Carcinogenic Contaminants 226

9.4.2. Soil Chemical Limits for the Non-carcinogenic Effects of Site Contaminants 227

9.5. Establishing Risk-Based Cleanup Limits for Contaminated Waters 229

9.5.1. Water Chemical Limits for Carcinogenic Contaminants 229

9.5.2. Water Chemical Limits for the Non-carcinogenic Effects of Site Contaminants 231

9.6. A 'Preferable' Health-Protective Chemical Level 232

9.6.1. The Modified RBCEL for Carcinogenic Chemicals 232

9.6.2. The Modified RBCEL for Non-carcinogenic Constituents 233

9.6.3. Incorporating Degradation Rates into the Estimation of Environmental Quality Criteria 234

9.7. Public Health Goals vs. Risk-Based Chemical Exposure Levels 235

Chapter 10 Design of Public Health Risk Management Programs 237

10.1. Risk Assessment as a Cost-Effective Tool in the Formulation of Public Health and Environmental Management Decisions 237

10.2. Comparative Risk Analysis: Application of Environmental Decision Analysis Methods to Public Health Risk Management Programs 239

10.2.1. Cost-Effectiveness Analysis 240

10.2.2. Risk-Cost-Benefit Optimization 240

10.2.3. Multi-attribute Decision Analysis and Utility Theory Applications 241

10.3. The General Nature of Risk Management Programs 245

10.4. A Framework for Risk Management Programs 247

10.5. Risk Communication as a Facilitator of Risk Management 249

10.5.1. Designing an Effectual Risk Communication Program 250

10.6. The Use of Contemporary Risk Mapping Tools: GIS in Public Health Risk Management Applications 251

10.6.1. Utilization of GIS in Risk Assessment and Environmental Management Programs 252

10.6.2. The Role of GIS Applications in Environmental Management 255

Chapter 11 The Role of Risk Assessment in Public Health Policy Decisions 257

11.1. General Scope of Public Health Risk Assessment Practice 257

11.1.1. Illustrative Examples of Public Health Risk Assessment in Practice 258

11.2. The Public Health Risk Assessment Paradigm 264

Appendix C Toxicity Index Parameters for Selected Chemicals 337.

Notes:

Includes bibliographical references (pages [275]-296) and index.

Local Notes:

Acquired for the Penn Libraries with assistance from the Rosengarten Family Fund.

ISBN:

1402009208

1402009216

OCLC:

50447822