Effects of Dioxin on Vietnamese Civilians

描述（由申请人提供） 生活在越南南部的平民可能是最容易接触二恶英的人群之一，其次是越南战争期间广泛喷洒的橙子剂和其他除草剂。 虽然二恶英对健康影响的程度仍有争议，但越南科学家的研究初步证据表明，接触二恶英的个人出生缺陷的发生率有所上升，尽管这些调查中的接触评估不足以提供令人信服的相关证据。 研究人员提出了一个病例对照研究的三种特定类型的出生缺陷在越南南部，病例和对照组从三个大型妇产医院在胡志明市。这些医院为来自越南南部各地的产妇提供服务。 研究者将研究以下病例：a）唇裂/腭裂，B）神经管缺陷，包括脊柱裂、无头畸形和小头畸形，以及c）肢体畸形/肢体复位。每个病例将招募一个对照组，针对特定出生缺陷类型的每个病例提供三个对照组。病例和对照将在出生后两天内招募。在获得知情同意后，将对国家出生缺陷预防研究问卷进行轻微修改。 将从母亲身上采集血液，用于血清二恶英和呋喃（总计加上17种单独的异构体加上WHO TEQ，包括多氯联苯，由AXYS分析服务有限公司进行，不列颠哥伦比亚省），总共加上111种多氯联苯同系物和多达78种农药（在奥尔巴尼进行）和芳烃受体的单核苷酸多态性（在辛辛那提进行）。 在假设越南南部50%的母亲将有显着的接触剂橙子的基础上，研究人员计算出，总共至少有163例的三种类型的出生缺陷，至少489个对照将提供权力，以检测风险增加的每一种类型的出生缺陷二恶英暴露的优势比为1.7。

DESCRIPTION (provided by applicant) Civilians living in southern Vietnam are likely to be among the most highly exposed population to dioxin, secondary to the widespread spraying of Agent Orange and other herbicides during the Vietnam War. While the magnitude of health effects of dioxin is still a matter of debate, there is preliminary evidence from studies by Vietnamese scientists indicating an elevation in the incidence of birth defects among exposed individuals, although exposure assessment in these investigations has not been adequate to provide convincing proof of association. The investigators propose a case-control study of three specific types of birth defects in southern Vietnam, with both cases and controls obtained from three large maternity hospitals in Ho Chi Minh City. These hospitals serve maternity patients from all of southern Vietnam. The investigators will study cases of a) cleft lip/cleft palate, b) neural tube defects, including spina bifida, anecephaly and microcephaly, and c) limb abnormalities/limb reduction. One control will be recruited for each case, giving three controls against each case of a particular birth defect type. Cases and controls will be recruited within two days of birth. After obtaining informed consent, a slight modification of the National Birth Defects Prevention Study questionnaire will be administered to the mother. Blood will be obtained from the mother for serum dioxin and furans (total plus 17 individual isomers plus WHO TEQs including PCBs, performed by AXYS Analytical Services Ltd., British Columbia), total plus 111 PCB congeners and up to 78 pesticides (performed in Albany) and single nucleotide polymorphisms of the aryl hydrocarbon (Ah) receptor (performed in Cincinnati). On the basis of the assumption that 50% of the mothers in southern Vietnam will have significant exposure from Agent Orange, the investigators calculate that a total of at least 163 cases of each of the three types of birth defect, and at least 489 controls will provide power to detect an elevated risk of each of these types of birth defects from dioxin exposure with an odds ratio of 1.7.