NEUROLOGIC HEALTH OUTCOMES AND AGENT-ORANGE - INSTITUTE-OF-MEDICINE REPORT

The National Academy of Sciences' Institute of Medicine conducted an i ndependent scientific investigation to evaluate the strength of eviden ce for human health effects among veterans exposed to herbicides used in Vietnam and to suggest future research recommendations. Neurologic domains where multiple studies had been performed in military, occupat ional, or environmental situations were (1) cognitive and neuropsychia tric effects, (2) motor/coordination dysfunction and other central ner vous system disorders, and (3) peripheral neuropathy. In all categorie s, no strong evidence established an association between herbicides us ed in Vietnam and clinical neurologic disorders. Methodologic weakness es, long durations between exposure and assessments, and poor exposure measures limited many studies. The committee concluded that the avail able evidence was insufficient to determine an association between neu rologic disorders and exposure to herbicides used in Vietnam. Neurotox icologic studies available did not suggest strong biological plausibil ity for neurologic alterations related to herbicide exposure. Furtherm ore, given the large uncertainties in the epidemiologic studies review ed and inadequate control for important confounders, the committee cou ld not quantify a degree of risk for neurologic disorders from herbici de exposure likely to be experienced by Vietnam veterans. Although not part of the neurologic report, the risk of brain tumors was considere d in the cancer analysis, and the committee concluded that there is li mited/suggestive evidence of no association between exposure to herbic ides and brain tumors.