Veterans and Agent Orange Update 2010 (2012) / Chapter Skim
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Appendix B: Short-Term Adverse Health Responses
Appendix B: Short-Term Adverse Health Responses
Pages 777-789
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From page 777... ...
reports. The three conditions that occur in tem poral proximity to exposure have little relevance for new claims from Vietnam veterans, and there has been minimal new evidence since they were classified as having evidence of an association with herbicide exposure The three conditions have long been recognized by the Department of Veterans Affairs as presumptively related to service in Vietnam.
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From page 778... ...
. If chloracne occurs, it appears shortly after the chemi cal exposure, not after a long latent period; therefore, new cases of chloracne among Vietnam veterans would not be the result of exposure during the Vietnam War.
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From page 779... ...
Synthesis No epidemiologic data in the past decade have refuted the conclusion of prior VAO committees that the evidence of an association between exposure to dioxin and chloracne is sufficient. The 2004 poisoning case of Ukrainian politician Victor Yuschenko has provided a high-profile instance that supports this condi tion as a response to high-level exposure to TCDD, and the careful monitoring of his case has demonstrated the course of chloracne's resolution in conjunction with subsiding serum concentrations (Sorg et al., 2009)
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From page 780... ...
PORPHYRIA CUTANEA TARDA Porphyrias are uncommon disorders caused by deficiencies of enzymes involved in the pathway of biosynthesis of heme, the iron-containing nonprotein portion of the hemoglobin molecule. PCT, the most common of the porphyrias, is a heterogeneous group of disorders caused by a deficiency of a specific enzyme, uroporphyrinogen decarboxylase.
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From page 781... ...
Among people who were exposed to TCDD as a result of the 1976 chemicalplant explosion in Seveso, Italy, clinical PCT was observed only in a brother and a sister who had a mutant enzyme that confers susceptibility in the heterozygous state. In 1977, 60 Seveso residents were tested for increased porphyrins, and 13 had secondary coproporphyrinuria; increased concentrations persisted in only three cases that were thought to be due to liver damage and alcohol consumption (Doss et al., 1984)
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From page 782... ...
Because TCDDassociated changes in porphyrin excretion become evident shortly after exposure, there is no risk that new cases will occur long after service in Vietnam. Given the recognized association between TCDD and porphyrin excretion and the long period that has elapsed since service in Vietnam, the committee concludes that the emergence of additional biologic and epidemiologic evidence that would merit review and deliberation by later VAO committees is unlikely.
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From page 783... ...
In March 1949, an explosion occurred in a reactor vessel at a chemical plant in Nitro, West Virginia, where 2,4,5-T was being produced. Many workers reported health effects (toxic hepati tis, increased serum lipids, and central nervous system involvement)
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From page 784... ...
Subjects had increased serum TCDD concentrations more than 30 years after exposure, and evidence of continued neuropathy was noted in 9 of 15 subjects who were available for study. Acute neuropathic symptoms were reported after the Seveso accident, and persistent signs were noted.
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From page 785... ...
Case reports do not provide conclusive evidence of causal relationships, but the cases discussed above showed a close temporal relationship between high exposure to 2,4-D and neuropathy. The most likely non–toxicant-related acute neuropathy is Guillain-Barré syndrome; however, this syndrome is associated with characteristic findings on clinical neurophysiologic examination and highly increased protein in CSF.
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From page 786... ...
1984. An Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides.
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From page 787... ...
1984. Development of chronic hepatic porphyria (porphyria cutanea tarda)
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From page 788... ...
1971. A health survey of workers in a 2,4-D and 2,4,5-T plant with special attention to chloracne, porphyria cutanea tarda, and psychologic parameters.
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From page 789... ...
2005. Constitutive expression of aryl hydrocar bon receptor in keratinocytes causes inflammatory skin lesions.
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