SERA TR-052-17-03b Strychnine Human Health and Ecological Risk Assessment FINAL REPORT Submitted to: Paul Mistretta, COR 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-08-0011 SERA Internal Task No. 52-17 Submitted by: Patrick R. Durkin Syracuse Environmental Research Associates, Inc. 8125 Solomon Seal Manlius, New York 13104 Fax: (315) 637-0445 E-Mail: [email protected] Home Page: www.sera-inc.com March 27, 2010 Table of Contents LIST OF TABLES ......................................................................................................................... vi LIST OF FIGURES ....................................................................................................................... vi LIST OF APPENDICES ............................................................................................................... vii ATTACHMENT ........................................................................................................................... vii ACRONYMS, ABBREVIATIONS, AND SYMBOLS .............................................................. viii COMMON UNIT CONVERSIONS AND ABBREVIATIONS .................................................... x CONVERSION OF SCIENTIFIC NOTATION ........................................................................... xi EXECUTIVE SUMMARY .......................................................................................................... xii 1. INTRODUCTION ...................................................................................................................... 1 2. PROGRAM DESCRIPTION ..................................................................................................... 4 2.1. OVERVIEW ........................................................................................................................ 4 2.2. CHEMICAL DESCRIPTION AND COMMERCIAL FORMULATIONS ....................... 4 2.3. APPLICATION METHODS ............................................................................................... 6 2.4. MIXING AND APPLICATION RATES ............................................................................ 6 2.5. USE STATISTICS ............................................................................................................... 7 2.6. RESTRICTIONS ON APPLICATION SITES .................................................................... 8 3. HUMAN HEALTH RISK ASSESSMENT .............................................................................. 10 3.1. HAZARD IDENTIFICATION ........................................................................................ 10 3.1.1. Overview ..................................................................................................................... 10 3.1.2. Mechanism of Action .................................................................................................. 10 3.1.3. Pharmacokinetics and Metabolism ............................................................................. 11 3.1.3.1. General Considerations ........................................................................................ 11 3.1.3.2. Dermal Absorption............................................................................................... 13 3.1.3.3. Excretion .............................................................................................................. 15 3.1.4. Acute Oral Toxicity .................................................................................................... 16 3.1.4.1. Effects in Humans ............................................................................................... 16 3.1.4.2. Effects in Experimental Mammals...................................................................... 18 3.1.4.2.1. Sex Difference in Sensitivity ........................................................................ 19 3.1.4.2.2. Age Difference in Sensitivity........................................................................ 20 3.1.5. Subchronic or Chronic Systemic Toxic Effects .......................................................... 22 Section 3.1.5.1. Multiple Doses in Mammals ................................................................... 22 3.1.5.2. Other Information ................................................................................................ 25 3.1.6. Effects on Nervous System ......................................................................................... 27 3.1.7. Effects on Immune System ......................................................................................... 27 3.1.8. Effects on Endocrine System ...................................................................................... 28 3.1.9. Reproductive and Developmental Effects .................................................................. 28 3.1.10. Carcinogenicity and Mutagenicity ............................................................................ 29 3.1.11. Irritation and Sensitization (Effects on the Skin and Eyes) ...................................... 29 3.1.11.1. Skin Irritation ..................................................................................................... 29 3.1.11.2. Skin Sensitization............................................................................................... 30 3.1.11.3. Ocular Effects .................................................................................................... 30 ii 3.1.12. Systemic Toxic Effects from Dermal Exposure ....................................................... 30 3.1.13. Inhalation Exposure .................................................................................................. 31 3.1.14. Inerts and Adjuvants ................................................................................................. 31 3.1.15. Impurities and Metabolites ....................................................................................... 31 3.1.16. Toxicological Interactions ........................................................................................ 31 3.2. EXPOSURE ASSESSMENT .......................................................................................... 33 3.2.1. Overview ..................................................................................................................... 33 3.2.2. Workers ....................................................................................................................... 34 3.2.2.1. General Exposures ............................................................................................... 34 3.2.2.1.1. Hand Baiting ................................................................................................. 34 3.2.2.1.2. Burrow Builder Applications ........................................................................ 39 3.2.2.2. Accidental Exposures........................................................................................... 40 3.2.3. General Public ........................................................................................................... 41 3.2.3.1.1. Likelihood and Magnitude of Exposure ....................................................... 41 3.2.3.1.2. Summary of Assessments ............................................................................. 41 3.2.3.2. Consumption of Bait by a Child .......................................................................... 42 3.2.3.3. Dermal Exposure from Contaminated Vegetation ............................................... 43 3.2.3.4. Contaminated Water ............................................................................................ 43 3.2.3.4.1. Accidental Spill ............................................................................................. 43 3.2.3.4.2. Accidental Direct Spray/drift for a Pond or Stream ...................................... 44 3.2.3.4.3. GLEAMS Modeling...................................................................................... 44 3.2.3.4.4. Other Modeling Efforts ................................................................................. 46 3.2.3.4.5. Monitoring Data ............................................................................................ 47 3.2.3.4.6. Concentrations in Water Used for Risk Assessment .................................... 49 3.2.3.5. Oral Exposure from Contaminated Fish .............................................................. 51 3.2.3.6. Dermal Exposure from Swimming in Contaminated Water ................................ 52 3.2.3.6. Oral Exposure from Contaminated Vegetation.................................................... 52 3.3. DOSE-RESPONSE ASSESSMENT ................................................................................. 54 3.3.1. Overview ..................................................................................................................... 54 3.3.2. Acute RfD ................................................................................................................... 54 3.3.3. Chronic RfD ................................................................................................................ 55 3.3.4. Dose-Severity Relationships ....................................................................................... 56 3.4. RISK CHARACTERIZATION ....................................................................................... 59 3.4.1. Overview ....................................................................................................................