Tamburro C H
Department of Medicine, University of Louisville, School of Medicine, Kentucky 40292.
Environ Res. 1992 Oct;59(1):175-88. doi: 10.1016/s0013-9351(05)80238-5.
Reports of hepatotoxic injury in Vietnam veterans exposed to phenoxy herbicides (mainly, 2,4-D and 2,4,5-T) initiated a retrospective cohort study of veterans self-reporting exposure to Agent Orange (AO) while serving in Vietnam from 1962 to 1971. Historical, medical, and laboratory information was obtained in a subcohort of 100 randomly selected veterans from a pool of 350 registrants. An occupational work exposure ranking system was designed to estimate individual exposure to phenoxy herbicide and its contaminant, dioxin (TCDD). Job classifications were determined by military job codes. Military application of the herbicides used in Vietnam were derived from the National Research Council Report based on the Herbs tapes. Health examination included tests of body systems affected by TCDD and similar agents, e.g., hemopoietic system, cholesterol/lipid metabolism, hepatic function, and skin lesions. Skin rash was utilized as a marker disease, since no case of true chloracne was found among the cohort. The cohort was divided into those with (R) and without (NR) a reported rash during or after the Vietnam tour. The R group had higher frequency (31%) of abnormal liver studies of all types than the NR group (18%). Of the 14 Vietnam veterans with persistent serum transaminase elevations, 86% reported a rash. Abnormal liver functions correlated with herbicide exposure index in both groups, but was more prominent in the R group. Study of the exposure index components showed that the liver abnormalities were related to the months of exposure and not to job classification or exposure rank. Viral hepatitis and alcoholism among both groups accounted for the association between liver abnormalities and cumulative exposure to AO. These data provide strong supportive evidence that chronic liver abnormalities among Vietnam veterans applying to the AO Registry are mainly due to viral or alcoholic causality and not to herbicides and their TCDD contaminant.
关于接触苯氧基除草剂（主要是2,4 - D和2,4,5 - T）的越南退伍军人出现肝毒性损伤的报告，引发了一项回顾性队列研究。该研究针对1962年至1971年在越南服役期间自我报告接触过橙剂（AO）的退伍军人。从350名登记人员中随机抽取100名退伍军人组成一个亚队列，获取其历史、医学和实验室信息。设计了一个职业工作暴露分级系统，以估计个体对苯氧基除草剂及其污染物二恶英（TCDD）的接触情况。工作分类由军事工作代码确定。越南使用的除草剂的军事应用源自基于除草剂磁带的国家研究委员会报告。健康检查包括对受TCDD和类似剂影响的身体系统进行测试，例如造血系统、胆固醇/脂质代谢、肝功能和皮肤病变。由于在该队列中未发现真正的氯痤疮病例，因此将皮疹用作标志性疾病。该队列被分为在越南服役期间或之后有（R）和没有（NR）报告皮疹的两组。R组各类肝脏检查异常的频率（31%）高于NR组（18%）。在14名血清转氨酶持续升高的越南退伍军人中，86%报告有皮疹。两组的肝功能异常均与除草剂暴露指数相关，但在R组中更为突出。对暴露指数成分的研究表明，肝脏异常与接触月份有关，而与工作分类或暴露等级无关。两组中的病毒性肝炎和酗酒是肝脏异常与AO累积接触之间关联的原因。这些数据提供了有力的支持证据，表明申请AO登记处的越南退伍军人中的慢性肝脏异常主要是由病毒或酒精引起的，而非除草剂及其TCDD污染物所致。
