California Environmental Protection Agency Air Resources Board Barrio Logan Report A Compilation of Air Quality Studies in Barrio Logan November 2004 This report has been approved by the staff of the Air Resources Board and approved for publication. Approval does not signify that the contents necessarily reflect the views and polices of the Air Resources Board, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. Acknowledgements The Air Resources Board staff wishes to express their appreciation for the assistance provided by the residents and business community of Barrio Logan, the Environmental Health Coalition, the San Diego County Air Pollution Control District, the Community Health Modeling Working Group, and other local government agencies of San Diego. TABLE OF CONTENTS CHAPTER 1 - INTRODUCTION............................................................................................................... 1 CHAPTER 2 - AIR MONITORING STUDIES IN BARRIO LOGAN ................................................... 5 A) AMBIENT AIR QUALITY MEASUREMENTS AT MEMORIAL ACADEMY CHARTER SCHOOL...................... 5 B) SPECIAL HEXAVALENT CHROMIUM MONITORING STUDY............................................................... 10 C) UNIVERSITY OF CALIFORNIA, RIVERSIDE SHORT-TERM TOXIC AIR MONITORING ........................... 13 D) FINDINGS FROM THE AMBIENT AIR MONITORING STUDIES ............................................................ 13 CHAPTER 3 - CONCEPTUAL MODELING APPROACH FOR ASSESSING CUMULATIVE IMPACTS.................................................................................................................................................... 15 A) NAP MODELING PROTOCOL....................................................................................................... 15 B) MICRO-SCALE DISPERSION MODELS .......................................................................................... 16 1) Micro-Scale Model Selection ............................................................................................ 17 2) Micro-Scale Data Requirements....................................................................................... 18 3) Micro-Scale Model Performance Evaluation..................................................................... 18 C) STATUS OF MICRO-SCALE MODELING NAP WORK...................................................................... 18 D) REGIONAL PHOTOCHEMICAL MODELS ......................................................................................... 20 1) Model Selection ................................................................................................................ 20 2) Regional Modeling Data Requirements............................................................................ 21 3) Regional Model Performance Evaluation ......................................................................... 21 E) METEOROLOGICAL MODELS ....................................................................................................... 22 1) Regional Meteorological Model Selection and Input Data Requirements ........................ 22 2) Regional Meteorological Model Performance Evaluation................................................. 23 F) INTEGRATION OF MODELING RESULTS ........................................................................................ 24 CHAPTER 4 - MODELING EMISSION INVENTORY DEVELOPMENT........................................ 25 A) BACKGROUND ........................................................................................................................... 25 B) REGIONAL EMISSION INVENTORY................................................................................................ 26 1) Gridded Inventory Terminology......................................................................................... 27 2) Point and Area Source Emissions .................................................................................... 28 3) On-Road Mobile Source Emissions.................................................................................. 35 4) Biogenic Emissions........................................................................................................... 40 5) Profiles of Toxic Air Pollutant Emissions .......................................................................... 42 6) Summary of the Regional Emission Inventory.................................................................. 44 C) MICRO-SCALE EMISSION INVENTORY.......................................................................................... 46 1) Summary of Micro-Scale Emission Inventory for Selected Toxic Air Pollutants............... 48 2) Special Micro-Scale Model Input Preparation................................................................... 55 3) Findings............................................................................................................................. 58 CHAPTER 5 - MODELING RESULTS FOR BARRIO LOGAN ......................................................... 61 A) MICRO-SCALE DISPERSION MODELING ....................................................................................... 62 1) Modeling Domain .............................................................................................................. 62 2) Micro-Scale Modeling Input Data...................................................................................... 63 3) Approaches to Assessing Model Performance................................................................. 66 4) Facility Specific Health Risk Assessments (HRAs) .......................................................... 77 5) Micro-Scale Modeling Results for Toxic Air Pollutants ..................................................... 78 6) Summary of Findings for the Micro-Scale Modeling......................................................... 89 B) REGIONAL PHOTOCHEMICAL MODELING...................................................................................... 90 1) Modeling Domain .............................................................................................................. 90 2) Regional Modeling Input Data........................................................................................... 92 3) Sensitivity Studies............................................................................................................. 97 4) Model Performance......................................................................................................... 102 5) Regional Modeling Results for Toxic Air Pollutants........................................................ 121 6) Inhalation Risk ................................................................................................................ 132 C) COMBINING MICRO-SCALE AND REGIONAL MODELING RESULTS ................................................ 139 1) Benzene.......................................................................................................................... 139 D) SUMMARY OF FINDINGS FOR THE REGIONAL PHOTOCHEMICAL MODELING .................................. 142 1) General Findings............................................................................................................. 142 2) Model Performance for Ozone........................................................................................ 142 3) Model Performance for Toxic Air Pollutants ................................................................... 143 4) Model Sensitivity Analyses ............................................................................................. 144 5) Model Limitations ............................................................................................................ 144 CHAPTER 6 - FINDINGS AND CONCLUSIONS ............................................................................... 147 A) AMBIENT AIR MONITORING SUMMARY ....................................................................................... 147 1) Memorial Academy Charter School ................................................................................ 147 2) Special Hexavalent Chromium Monitoring Study ........................................................... 148 3) General Findings............................................................................................................. 148 B) EMISSION INVENTORY SUMMARY .............................................................................................. 149 C) MICRO-SCALE MODELING SUMMARY ........................................................................................ 150 D) REGIONAL PHOTOCHEMICAL MODELING SUMMARY.................................................................... 150 E) INTEGRATION OF REGIONAL AND MICRO-SCALE MODELING SUMMARY ....................................... 152 F) RISK SUMMARY ....................................................................................................................... 152 G) CONCLUSIONS AND RECOMMENDATIONS................................................................................... 153 CHAPTER 7 - REFERENCES................................................................................................................ 155 APPENDIX A............................................................................................................................................ 165 INTRODUCTION CHAPTER 1 - INTRODUCTION In 1999, the Air Resources Board (ARB) established the Neighborhood Assessment