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Item ID Number °1165 Author Young, Alvin L. United States Air Force Occupational and Environmental Report/Article Title The Toxicology, Environmental Fate, and Human Risk of Herbicide Orange and its Associated Dioxin Journal/Book Title Year Month/Day Oct°ber Color D Number of Images 263 DeSCrlptOU NOtBS A'v'n *-• Young filed this item under the category "Human Exposure to Phenoxy Herbicides and TCDD" Thursday, April 05, 2001 Page 1165 of 1180 • 4 MTlftrO A-L. eVdL Report OEHLTR-78-92 r ^j-—-' j •••4>^ USAF OEHL TECHNICAL REPORT THE TOXICOLOGY, ENVIRONMENTAL FATE, AND HUMAN RISK OF HERBICIDE ORANGE AND ITS ASSOCIATED DIOXIN Alvin L. Young, Captain, USAF John A. Calcagni, Lieutenant Colonel, USAF, MC Charles E. Thalken, Lieutenant Colonel, USAF, VC James W. Tremblay, Major, USAF, BSC October 1978 Final Report I Approved for public release; distribution unlimited PREPARED FOR: The Surgeon General United States Air Force Washington, D.C. 20314 USAF Occupational and Environmental Health Laboratory Aerospace Medical Division (AFSC) Brooks Air Force Base, Texas 78235 NOTICES This report has been released to the National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161, for sale to the general public. *** Qualified requestors may obtain copies of this report from Defense Documentation Center (DDC), Cameron Station, Alexandria, Virginia 22314. *** This technical report has been reviewed and is approved for publication. WILLIAM E. MABSON, Colonel, USAF, BSC Commander UNCLASSIFIED SECURTtV'tVASSIFICATION OF THIS PAGE (When Data Entered) READ INSTRUCTIONS REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM 1. REPORT NUMBFR 2. GOVT ACCESSION NO 3. RECIPIENT'S CATALOG NUMBER USAF OEHL -78-92 it".; ':" C-inrt Subtitle) 5. TYPE OF REPORT & PERIOD COVERED The Toxicology, Environmental Fate and Human Risk Fin; I of Herbicide Orange and Its Associated Dioxin 6. PERFORMING ORG. REPORT NUMBER -.• i,- 3 • - • , . ?. AUTHOR,,, /\yvin L. young, Captain, USAF 8. CONTRACT OR GRANT NUMBERfa.) John A. Calcagni, Lieutenant Colonel, USAF, MC Charles E. Thai ken, Lieutenant Colonel, USAF, VC: James U. Tremblay, Major. USAF, BSC 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, TASK US Air Force Occupational and Environmental Health ARc A & WORK UNIT NUMBERS Laboratpry Brooks AFB TX 78235 11. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE The Surgeon General October 1978 US Air 'Force 13. NUMBER OF PAGES Washington, DC 20314 14 MONITORING AGENCY NAME 4 ADDRESS^/ different Iron Controlling Olficv) 15. SECURITY CLASS, (at this report) Unclassified 1Sa. DECLASSIFI CATION/ DOWN GRADING SCHEDULE 16. DISTRIBUTION STATEMENT (ol this Report) Approved for public release; distribution unlimited. 17. DISTRIBUTION STATEMENT (ol the abstract entered In Block 30, It different tram Report) 18. SUPPLEMENTARY NOTES Authors: A.L. Young, PhD J.W. Tremblay, P.E. J.A. CaVcagni, MD C.E. Thalken, DVM 19. KEY WORDS (Continue on reverse aide II nocessary and identity by block number) clorinated phenols Herbicide Orange toxicity - animal 2,4-dichlorophenoxyacetic acid (2,4-D) phenoxy herbicides toxicity - human dioxin Pacer HO environmental monitoring Ranch Hand herbicides South Vietnam 20. ABSTRACT fContinue on reverse aide If necnssary and Identify by block number) The use of herbicides in South Vietnam between 1962 and 1971 was reviewed, in- cluding the nature and quantities of herbicides used, their handling and applica- tion.' Emphasis was placed on Herbicide Orange, a 50:50 mixture of 2,4-dichloro- phenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), with its associated contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The at- risK US military population in South Vietnam was defined to establish the potential for exposure in handling "and application of Herbicide Orange. The environmental fate of the phenoxy herbicides and TCDD was reviewed to evaluate EO.TIOM OF I- . ' 65 IS OBSOLETE UNCLASS I F I FD SS.CURITY CLASSI f: » iT, r;)AGE (Wien Deta Entt-rr ' UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAOBftWiwi £>•<« Entered) Item 19. Key Words (cont): 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) Item 20. Abstract (cont): the potential for human risk associated with exposure to areas previously treated with Herbicide Orange. The occupational and environmental aspects of the project to incinerate at sea 2.22 million gallons of Herbicide Orange durinc the summer of 1977 were summarized to assess the potential for human exposure in handling large quantities of the material. Scientific data were reviewed on incidents and episodes involving suspected poisoning of humans or animals by phenoxy herbicides or TCDD. Literature dealing with animal toxicology and the effects of human exposure to 2,4-D, 2,4,5-T and TCDD was reviewed to correlate exposures with symtomatology. iv UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGEfHTion Data Entered) PREFACE The use of herbicides in support of tactical military operations in South Vietnam from 1961 to 1971 has had (and continues to have) a nega- tive impact on the use of pesticides by numerous facets of our society. fjrior to the Vietnam conflict, herbicides were considered invaluable to agriculture, innocuous to human life and of little environmental concern. Today, seven years after the last herbicide mission in Vietnam, these same herbicides are the center of scientific debate involving not only ecological but also medical, legal and political issues. The United States Environmental Protection Agency (EPA) has recently issued a Notice of Rebuttable Presumption Against Registration (RPAR) of pesticides con- taining one of these "Vietnam" herbicides, while at the same time some Veterans of the Vietnam Conflict have reported medical problems they claimed were the result of herbicide exposure while assigned to military duties in Vietnam. In April 1978, the Surgeon General of the United States Air Force (USAF) tasked personnel'of the USAF Occupational and Environmental Health Laboratory, Brooks AFB, Texas with updating previous scientific assessments of possible adverse effects to human health resulting from exposure to the herbicides, especially Herbicide Orange used in South Vietnam during the Vietnam Conflict. The present report was assembled using the latest available published scientific information, previously unpublished data, and observations from medical and scientific personnel intimately associated with the herbicides in question. The report reviews the use of phenoxy herbicides in Vietnam, their environmental fate, and pertinent animal and human toxicological studies. In addition, a description is given of the 1977 military operation for the disposal of Herbicide Orange emphasizing the facets of environ- mental monitoring and industrial hygiene. The document concludes with an assessment of the risk to human health following exposures to the phenoxy herbicides. Special emphasis was placed upon the chemistry, environmental fate and toxicology of the trichlorophenoxy herbicide contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin). The authors are indebted to Kenneth C. Back, PhD, Chief Toxicology Branch, Toxic Hazards Division, United States Air Force 6570th Aerospace Medical Research Laboratory, Wright-Patterson AFB Ohio for his critical review of-this document and the many recommendations he made to improve the qualify of the discussions on toxicology. Special thanks are expressed to Rodney W. Bovey, PhD, United States Department of Agriculture", Texas A&M University, College Station, Texas, for his assistance in providing copies of the foreign literature on the phenoxy herbicides. The services of many staff members and consultants of the United States Air Force Occupational and Environmental Health Laboratory are acknowledged. Special acknowledgement is made to Mrs Joyce G. Kidd who served as the general editor, and to the following typists who willingly worked numerous overtime hours in preparing this manuscript: Ruth S. Bledsoe; Yolanda Carrisalez; Irma Ledesma; Lorraine M. Polonis; Nancy L. Ragan and Trina Roark. CONTENTS Page PREFACE v CHAPTER I .THE USE OF HERBICIDES IN SOUTH VIETNAM I. INTRODUCTION 1-1 II. THE HERBICIDES USED IN SOUTH VIETNAM 1-1 A. Historical 1-1 B. Descriptions of the Herbicides Used in Operation RANCH HAND 1-3 C. Quantities of Herbicides Sprayed in South Vietnam 1-8 D. Land Area Sprayed with Herbicides in South Vietnam 1-11 III. THE AIRCRAFT, SPRAY SYSTEMS AND MISSION CONCEPT IN OPERATION RANCH HAND I-11 A. Historical 1-11 B. Spray Systems and Characteristics of the RANCH HAND Aircraft 1-14 C. Mission Concepts 1-15 IV. PERTINENT DEPLOYMENT AND BIOLOGICAL FACTORS OF THE HERBICIDES 1-18 A. Use Patterns of Individual Military Herbicides 1-18 B. Canopy Penetration of Defoliants 1-20 « V. ESTIMATED QUANTITIES OF INDIVIDUAL CHEMICALS SPRAYED IN SOUTH VIETNAM A. Herbicide Orange and its Components 2,4-D, 2,4,5-T and TCDD 1-21 B. Military Projects that Involved Handling Herbicides Orange, Purple, Pink or Green 1-29 VI. SUMMARY 1-29 LITERATURE CITED 1-32 LIST OF TABLES 1. Selected physical, chemical and toxicological properties of the three major military herbicides used in South Vietnam, 1962 - 1971. 1-5 VI 1 2. Number of gallons of military herbicide procured by the U.S. Department of Defense and disseminated in South Vietnam during the period January 1962 - December 1964. 1-9 3. Estimated number of gal of military herbicide procured by the U.S. Department of Defense and disseminated in South Vietnam during the period January 1965 - February 1971. 1-10 4. Comparison of data from three sources of the estimated number of acres treated in South Vietnam during the period of January 1962 - February 1971. Data make noi allowance for multiple coverage. 1-12 5. The number of acres treated in South Vietnam, 1962 - 1971, with military herbicides within the three major vegeta- tional categories. Data represent areas receiving single or multiple coverage and for 90 percent of all areas treated. 1-13 6. Concentration, ppm, of TCDD in samples of Herbicides Orange and Purple. 1-23 7. Composition, percent, of selected samples of Herbicide Orange in relation to military specifications.