title: Handler, bystander and reentry exposure to TCDD from application of Agent Orange by C-123 aircraft during the Vietnam War.
abstract: Using validated models and methods routinely employed by pesticide regulatory agencies, the absorbed dosages of Agent Orange (AO) herbicide contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were estimated for mixer/loaders, applicators, and individuals in the vicinity of applications of AO by C-123 aircraft during the Vietnam War. Resulting dosages of TCDD were then transformed to estimates of adipose residues, and compared to population biomonitoring of known mixer/loaders and applicators as well as ground troops in Vietnam and civilians in the U.S. Results demonstrate that mixer/loaders and applicators had the greatest exposures and their measured residues of TCDD in adipose were consistent with the estimated exposures. Further, the potentially exposed ground troops, including those who could have been directly sprayed during aerial defoliation, had measured adipose residues that were consistent with those in civilian U.S. populations with no defined source of exposure exposures and both of those cohorts had orders of magnitude less exposure than the mixer/loaders or applicators. Despite the availability of validated exposure modeling methods for decades, the quantitative TCDD dose estimates presented here are the first of their kind for the Vietnam conflict.
authors.affiliation: risksciences.net, LLC, 5150 Fair Oaks Blvd. #101-370, Carmichael, CA 95608, United States. Electronic address: jhross@surewest.net.
authors.forename: John H
authors.initials: JH
authors.lastname: Ross
authors.affiliation: Centre for Pesticide Application and Safety, The University of Queensland, Gatton QLD 4343, Australia; Lincoln University, Christchurch 7640, New Zealand; The University of Nebraska, North Platte, NE, United States.
authors.forename: Andrew
authors.initials: A
authors.lastname: Hewitt
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Armitage
authors.affiliation: Centre for Toxicology, School of Environmental Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
authors.forename: Keith
authors.initials: K
authors.lastname: Solomon
authors.affiliation: M.E. Ginevan & Associates, 307 Hamilton Ave., Silver Spring, MD 20901, USA.
authors.forename: Deborah K
authors.initials: DK
authors.lastname: Watkins
authors.affiliation: M.E. Ginevan & Associates, 307 Hamilton Ave., Silver Spring, MD 20901, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Ginevan
mesh_terms: D015085:2,4,5-Trichlorophenoxyacetic Acid; D015084:2,4-Dichlorophenoxyacetic Acid; D000075182:Agent Orange; D000401:Aircraft; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D004785:Environmental Pollutants; D006801:Humans; D000072317:Polychlorinated Dibenzodioxins; D047829:Vietnam Conflict
chemical_list: D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D015084:2,4-Dichlorophenoxyacetic Acid; D000075182:Agent Orange; D015085:2,4,5-Trichlorophenoxyacetic Acid
keywords: Agent Orange; Exposure; Operation Ranch Hand; TCDD; Veteran; Vietnam