CHAPTER 4 DETAILED HUMAN HEALTH RISK ASSESSMENT METHODOLOGY FINAL REPORT CHAPTER 4: DETAILED HUMAN HEALTH RISK ASSESSMENT METHODOLOGY Table of Contents Page 4.0 DETAILED HUMAN HEALTH RISK ASSESSMENT METHODOLOGY ..................... 4-1 4.1 Exposure Assessment ............................................................................................. 4-1 4.1.1 Media Concentration Data Selected for Use in the HHRA ............................... 4-2 4.1.1.1 Surface Soil Concentrations ....................................................................... 4-2 4.1.1.2 Ambient Air Concentrations ........................................................................ 4-3 4.1.1.3 Indoor Air Concentrations ........................................................................... 4-6 4.1.1.4 Drinking Water Concentrations................................................................... 4-7 4.1.1.5 Vegetable Garden Produce Concentrations ............................................... 4-9 4.1.1.6 Fish Tissue Concentrations ......................................................................... 11 4.1.1.7 Indoor Dust Concentrations ...................................................................... 4-15 4.1.1.8 Wild Game Tissue Concentrations ........................................................... 4-18 4.1.1.9 Local Blueberries ..................................................................................... 4-19 4.1.1.10 Surface Water and Sediment ................................................................... 4-21 4.1.1.11 Snow ........................................................................................................ 4-21 4.1.2 Background Exposure Assessment .............................................................. 4-22 4.1.3 Market Basket Estimated Daily Intakes ......................................................... 4-25 4.1.4 Summary of EPC Data used in the HHRA .................................................... 4-32 4.1.5 Exposure Assessment of Carcinogens ......................................................... 4-34 4.1.6 Deterministic versus Probabilistic Exposure Analysis ................................... 4-34 4.1.7 Exposure Estimation Methods ...................................................................... 4-35 4.1.7.2 Exposure through Inhalation of Outdoor and Indoor Air ............................ 4-40 4.1.7.3 Exposure via Consumption of Home Garden Vegetables ......................... 4-41 4.1.7.4 Exposure via Consumption of Local Wild Blueberries .............................. 4-42 4.1.7.5 Exposure via Consumption of Drinking Water .......................................... 4-43 4.1.7.6 Exposure via Consumption of Locally Caught Fish ................................... 4-44 4.1.7.7 Exposure via Consumption of Local Wild Game ....................................... 4-45 4.1.7.8 Exposure while Swimming in Local Lakes ................................................ 4-47 4.1.7.9 Market Food Basket Exposure ................................................................. 4-49 4.1.8 Development of the Risk Assessment Modelling Tool ................................... 4-51 4.1.9 Use of the IEUBK Model to Predict Blood Lead Levels in Children ............... 4-51 4.1.9.1 Components of the IEUBK Model ............................................................. 4-51 4.1.9.2 IEUBK Model Application for the HHRA ................................................... 4-55 4.1.9.3 Site-Specific Parameters Used within the IEUBK Model........................... 4-56 4.2 Hazard Assessment ............................................................................................... 4-61 4.2.1 Overview of Exposure Limits Selected for the HHRA .................................... 4-63 4.2.2 Selection of Toxicological Criteria for the HHRA ........................................... 4-63 4.2.3 Summary of Toxicological Profiles ................................................................ 4-69 4.2.3.1 Arsenic ..................................................................................................... 4-69 4.2.3.2 Cadmium ................................................................................................. 4-73 4.2.3.3 Copper ..................................................................................................... 4-77 4.2.3.4 Lead ......................................................................................................... 4-80 4.2.3.5 Mercury .................................................................................................... 4-87 4.2.3.6 Selenium .................................................................................................. 4-93 4.2.4 Bioavailability/Bioaccessibility ....................................................................... 4-97 HHRA-Chapter 4: Detailed HHRA Methodology June, 2010 Human Health Risk Assessment of Flin Flon, Manitoba, and Creighton, Saskatchewan FINAL REPORT 4.2.5 Speciation ..................................................................................................... 4-98 4.3 Risk Characterization ............................................................................................. 4-99 4.3.1 Evaluation and Interpretation of Hazard Quotients and Incremental Lifetime Cancer Risk ................................................................................... 4-100 4.3.2 Consideration of Chemical Mixtures ........................................................... 4-102 4.3.3 Sensitivity Analysis and Identification of Uncertainties and Limitations ....... 4-103 4.4 Risk Management Recommendations.................................................................. 4-103 4.5 References .......................................................................................................... 4-104 HHRA-Chapter 4: Detailed HHRA Methodology June, 2010 Human Health Risk Assessment of Flin Flon, Manitoba, and Creighton, Saskatchewan FINAL REPORT CHAPTER 4 DETAILED HUMAN HEALTH RISK ASSESSMENT METHODOLOGY List of Tables Page Table 4-1 Exposure Point Concentrations for COC Measured in Residential ................... 4-2 Surface Soil (µg/g) ........................................................................................... 4-2 Table 4-2 Annual Average COC Concentrations Associated with PM10 in ....................... 4-4 Ambient Air (µg/m3) ......................................................................................... 4-4 Table 4-3 Correlating Factors Used to Predict COC Content of PM10 Based on Concentrations Measured in TSP ..................................................................... 4-5 Table 4-4 Exposure Point Concentrations for COC Measured in Outdoor Air µg/m3) .............................................................................................................. 4-5 Table 4-5 Exposure Point Concentrations for COC Measured in Flin Flon ....................... 4-7 Drinking Water (µg/L) ....................................................................................... 4-7 Table 4-6 Exposure Point Concentrations for COC Measured in Creighton ..................... 4-8 Drinking Water (µg/L) ....................................................................................... 4-8 Table 4-7 Exposure Point Concentrations for COC Measured in Home Garden ............. 4-11 Vegetables (µg/g ww) ..................................................................................... 4-11 Table 4-8 95% UCLM Concentrations for COC in Local Fish for Individual Species (µg/g ww) .......................................................................................... 4-12 Table 4-9 95% UCLM Concentrations for COC in Fish for Individual Lakes (µg/g ww) ....................................................................................................... 4-12 Table 4-10 Exposure Point Concentrations for COC in Fish (µg/g ww) ............................ 4-13 Table 4-11 Methyl Mercury Content in Local Fish Tissue Samples .................................. 4-13 Table 4-12 Concentrations of COC Measured in Indoor Dust (µg/g) ................................ 4-15 Table 4-13 Predicted Concentrations of COC in Indoor Dust Based on EPC Outdoor Soil Concentrations and Site-Specific Regression Equations and the IEUBK MSA Module for Lead (µg/g) ................................. 4-16 Table 4-14 Indoor Dust EPCs Derived Based on Measured Dust Concentrations Versus Predicted Indoor Dust EPCs Derived Based on EPC Outdoor Soil Concentrations and Site-Specific Regression Equations and the IEUBK MSA Module for Lead (µg/g) ............................................................... 4-17 Table 4-15 Exposure Point Concentrations for COC in Indoor Dust (µg/g) ....................... 4-18 Table 4-16 Exposure Point Concentrations for COC in Wild Game (µg/g ww) .................. 4-18 Table 4-17 Weighted EPCs for the Consumption of Wild Game (µg/g ww) ...................... 4-19 Table 4-18 Exposure Point Concentrations for COC in Local Blueberries (µg/g ww) ........ 4-20 Table 4-19 Maximum Concentrations of COC in Surface Water (n=12) ........................... 4-21 Table 4-20 Exposure Point Concentrations for COC Measured in Flin Flon Sediments (µg/g) ............................................................................................ 4-21 Table 4-21 Exposure Point Concentrations for COC Measured in Flin Flon Snow (µg/L).................................................................................................... 4-22 Table 4-22 Typical