Air- Hot Spots Guidelines

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Notice to Interested Parties Air Toxics "Hot Spots" Program Risk Assessment Guidelines Part IV Exposure Assessment and Stochastic Analysis Technical Support Document October 27, 2000
go to download area The Office of Environmental Health Hazard Assessment (OEHHA) is the releasing the final document, Air Toxics Hot Spots Program Risk Assessment Guidelines Part IV: Exposure Assessment and Stochastic Analysis Technical Support Document . This document is the fourth in a series of five Risk Assessment Guidelines that are being developed by OEHHA for use in implementing the Air Toxics "Hot Spots" Program mandated by the Air Toxics Hot Spots Information and Assessment Act of 1987, as amended. An External Advisory Group composed of scientists from industry, academia, environmental groups, Federal and State agencies met fourteen times to provide scientific input. The original draft document was released in December 1996 for a 90-day public comment period, followed by two public workshops, a second review draft was released on March 10, 2000. Please direct any inquiries concerning technical matters or availability of the document to: Dr. Robert Blaisdell at (510) 622-3150. Information about dates and agenda for meetings of the Scientific Review Panel can be obtained from the ARB web page at http://www.arb.ca.gov/srp/srp.htm. The document is available for download in one 4.3 Mb file or in several sections. Click a link below to download. Download the entire document (excluding appendices) Download Appendices A-K Download the memo detailing the adoption of this technical support document. Download individual Sections Table of Contents Executive Summary Section 1: Introduction 1.1 Multipathway Nature of Exposure Assessment 1.2 The Point Estimate Approach 1.3 The Stochastic Approach ("Likelihood of Risks" Approach) 1.4 Tiered Approach to Risk Assessment 1.5 Exposure Assessment Pathways 1.6 References Section 2: Air Dispersion Modeling 2.1 Air Dispersion Modeling in Risk Assessment: Overview 2.3 Source Characterization 2.3.2 Classification According to Quantity of Sources 2.4 Terrain Characterization 2.5 Level of Detail: Screening vs. Refined Analysis 2.6 Population Exposure 2.7 Receptor Siting 2.8 Meteorological Data 2.9 Model Selection 2.10 Screening Air Dispersion Models 2.11 Refined Air Dispersion Models 2.12 Modeling Special Cases 2.13 Specialized Models 2.14 Interaction with the District 2.15 Report Preparation 2.16 References Section 3: Daily Breathing Rates 3.1 Introduction 3.2 Methods for Estimating Daily Breathing Rates 3.3 Available Data on Breathing Rates 3.4 Ranges of Ventilation Rates 3.5 Use of Activity Patterns and Ventilation Rate Data to Develop Breathing Rate Distribution 3.5.1 CARB Sponsored Activity Pattern Studies 3.6 Recommendations 3.7 References Section 4: Soil Ingestion Rates 4.1 Introduction 4.2 Current CAPCOA Algorithm for Dose from Soil Ingestion 4.3 Proposed Algorithm for Dose via Soil Ingestion 4.4 Soil Ingestion Studies 4.5 Studies in Adults - Calabrese et al. (1990) 4.6 Distributions of Soil Ingestion Estimates 4.7 Recommendations 4.8 References Section 5: Breast Milk Consumption Rate 5.1 Introduction 5.2 Breast Milk Consumption Among Breast-feeding Infants 5.3 Breast Milk Consumption in the General Population 5.4 Lipid Concentration and Distribution of Lipid Intake 5.5 Concluding Remarks 5.6 Recommendations 5.7 References Section 6: Dermal Exposure Assessment 6.1 Introduction 6.2 Factors Providing Significant Variation in Dermal Uptake 6.3. Exposure Factors and Studies Evaluated 6.4 Dermal Uptake Estimation Equations 6.5 Recommendations 6.6 References Section 7: Food Intake 7.1 Introduction 7.2 Algorithm for Food Intake Dose 7.3 Methods and Studies Available for Estimation of Per Capita Consumption 7.4 Categorization of Produce 7.5 Produce, Meat, Dairy and Egg Consumption Distributions 7.6 Calculating Contaminant Concentrations in Food 7.7 Default Values for Calculation of Food Contaminant 7.8 Summary 7.9. Recommendations 7.10 References Section 8: Water Intake 8.1 Introduction 8.2 Empirical Distributions 8.3 Modeled Distributions 8.4 Recommendations 8.5 References Section 9: Fish Consumption 9.1 Introduction 9.2 Algorithm for Dose via Fish Ingestion 9.3 Studies Evaluated for Noncommercial Fish Consumption Parameter 9.4 Determination of Fish Consumption Distribution 9.5 Statistical Treatment 9.6 Recommendations Section 10: Body Weight 10.1 Introduction 10.2 Empirical Distributions 10.3 Modeled Distributions 10.4 Recommendations 10.5 References Section 11: Exposure Duration 11.1 Introduction 11.2 Dose Algorithm and Duration of Exposure 11.3 Available Studies for Evaluating Residency Time 11.4 Discussion 11.5 Recommendations 11.6 References Appendix A: List of Substances Appendix B: Health and Safety Code Related to Hot Spots Program Appendix C: (text only) We are trying to get the graphics down to a manageable size. Sorry for the delay. Produce, Meat, Dairy and Egg Consumption Empirical Distributions (Gm/day) Comparison of Produce, Meat, Dairy and Egg Empirical Consumption Distributions (Gm/Kg BW/Day) with Parametric Models Appendix D: CSFII Food Categories Used to Determine Per Capita Food Consumption Appendix E: Determination of Chemicals for Multipathway Analysis Appendix F: Dermal Absorption Factors Appendix G: Chemical-specific Soil Half Life Appendix H: Fish Bioconcentration Factors (BCF) Appendix I: Glossary and List of Acronyms Appendix J: HRA Forms and Maps Used With Air Dispersion Modeling Appendix K: Comparison of Breathing Rates Distribution to Energy Expenditure Information You will need the free program Adobe Acrobat Reader to view or print PDF files For help with this web site please contact the Web Mistress