SERA TR-052-04-04a Aminopyralid Human Health and Ecological Risk Assessment – FINAL REPORT Prepared for: USDA/Forest Service and National Park Service Submitted to: Paul Mistretta, COR Joy Frier-Scott, Contracting Officer USDA/Forest Service, Southern Region 1720 Peachtree RD, NW Atlanta, Georgia 30309 USDA Forest Service Contract: AG-3187-C-06-0010 USDA Forest Order Number: AG-43ZP-D-06-0018 SERA Internal Task No. 52-04 Prepared by: Patrick R. Durkin Syracuse Environmental Research Associates, Inc. 5100 Highbridge St., 42C Fayetteville, New York 13066-0950 Fax: (315) 637-0445 E-Mail: [email protected] Home Page: www.sera-inc.com June 28, 2007 Table of Contents List of Tables ................................................................................................................................. iv List of Figures................................................................................................................................iv List of Appendices .......................................................................................................................... v ACRONYMS, ABBREVIATIONS, AND SYMBOLS ................................................................ vi COMMON UNIT CONVERSIONS AND ABBREVIATIONS................................................... ix CONVERSION OF SCIENTIFIC NOTATION ............................................................................ x EXECUTIVE SUMMARY ........................................................................................................... xi 1. Introduction................................................................................................................................. 1 2. PROGRAM DESCRIPTION..................................................................................................... 5 2.1. OVERVIEW ....................................................................................................................... 5 2.2. CHEMICAL DESCRIPTION AND COMMERCIAL FORMULATIONS....................... 5 2.3. APPLICATION METHODS.............................................................................................. 7 2.4. MIXING AND APPLICATION RATES ........................................................................... 8 2.5. USE STATISTICS............................................................................................................ 10 3. HUMAN HEALTH RISK ASSESSMENT............................................................................. 12 3.1. HAZARD IDENTIFICATION......................................................................................... 12 3.1.1. Overview.................................................................................................................... 12 3.1.2. Mechanism(s) of Action ............................................................................................ 13 3.1.3. Pharmacokinetics and Metabolism ............................................................................ 19 3.1.4. Acute Oral Toxicity ................................................................................................... 25 3.1.5. Subchronic or Chronic Systemic Toxic Effects......................................................... 26 3.1.6. Effects on Nervous System........................................................................................ 29 3.1.7. Effects on Immune System ........................................................................................ 30 3.1.8. Effects on Endocrine System..................................................................................... 31 3.1.9. Reproductive and Teratogenic Effects....................................................................... 32 3.1.10. Carcinogenicity and Mutagenicity........................................................................... 34 3.1.11. Irritation and Sensitization (Effects on the Skin and Eyes) ..................................... 35 3.1.12. Systemic Toxic Effects from Dermal Exposure ...................................................... 36 3.1.13. Inhalation Exposure ................................................................................................. 36 3.1.14. Inerts and Adjuvants ................................................................................................ 37 3.1.15. Impurities and Metabolites ...................................................................................... 39 3.1.16. Toxicological Interactions ....................................................................................... 41 3.2. EXPOSURE ASSESSMENT ........................................................................................... 43 3.2.1. Overview.................................................................................................................... 43 3.2.2. Workers...................................................................................................................... 43 3.2.3. General Public............................................................................................................ 47 3.3. DOSE-RESPONSE ASSESSMENT ................................................................................ 62 3.3.1. Overview.................................................................................................................... 62 3.3.2. Chronic RfD............................................................................................................... 62 3.3.3. Acute RfD .................................................................................................................. 63 ii 3.4. RISK CHARACTERIZATION......................................................................................... 65 3.4.1. Overview..................................................................................................................... 65 3.4.2. Workers....................................................................................................................... 65 3.4.3. General Public............................................................................................................. 67 3.4.4. Sensitive Subgroups................................................................................................... 69 3.4.5. Connected Actions..................................................................................................... 70 3.4.6. Cumulative Effects...................................................................................................... 70 4. ECOLOGICAL RISK ASSESSMENT ................................................................................... 72 4.1. HAZARD IDENTIFICATION......................................................................................... 72 4.1.1. Overview.................................................................................................................... 72 4.1.2. Toxicity to Terrestrial Organisms.............................................................................. 73 4.1.3. Aquatic Organisms..................................................................................................... 79 4.2. EXPOSURE ASSESSMENT ........................................................................................... 84 4.2.1. Overview.................................................................................................................... 84 4.2.2. Terrestrial Animals .................................................................................................... 85 4.2.3. Terrestrial Plants ........................................................................................................ 88 4.2.4. Soil Organisms........................................................................................................... 92 4.2.5. Aquatic Organisms..................................................................................................... 93 4.3. DOSE-RESPONSE ASSESSMENT ................................................................................ 94 4.3.1. Overview.................................................................................................................... 94 4.3.2. Toxicity to Terrestrial Organisms.............................................................................. 95 4.3.3. Aquatic Organisms..................................................................................................... 99 4.4. RISK CHARACTERIZATION...................................................................................... 102 4.4.1. Overview.................................................................................................................. 102 4.4.2. Terrestrial Organisms............................................................................................... 103 4.4.3. Aquatic Organisms................................................................................................... 107 5. REFERENCES ....................................................................................................................... 110 iii List of Tables Table 1: Commercial Formulations Containing Aminopyralid.................................................. 128 Table 2: Selected Physical and Chemical Properties of Aminopyralid ...................................... 129 Table 3: Agents causing cecal enlargement in rats..................................................................... 132 Table 4: Chemical and site parameters used in GLEAMS modeling for aminopyralid ............. 133 Table 5: Summary of modeled concentrations