Mercury Vapor from Amalgam and Methylmercury Co-Exposure on Neurodevelopment

汞合金中的汞蒸气和甲基汞共同暴露对神经发育的影响

• 批准号: 7478316
• 负责人: GENE E WATSON
• 金额: $ 57.38万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-03 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7478316
• 关键词: Accounting; Adverse effects; Age; Age-Months; Age-Years; Attention; Biological Sciences; Blood - brain barrier anatomy; Breast Feeding; Child; Child Development; Clinical; Cognitive; Cohort Studies; Computer information processing; Congresses; Consumption; Data; Dental; Dental Amalgam; Dental Care; Dental Records; Dentition; Development; Dimensions; Dose; Enrollment; Ensure; Epidemiologic Studies; Evaluation; Exposure to; Fetus; Fishes; Genes; Hair; Health; Home environment; Human; Iodine; Iron; Laboratory Animals; Late Effects; Link; Masks; Measurement; Measures; Mercury; Methylmercury Compounds; Minerals; Mothers; Neurotoxins; Nutrient; Nutritional; Nutritional status; Observational Study; Oceans; Oral Examination; Outcome; Perinatal Exposure; Personal Satisfaction; Placement; Poison; Polyunsaturated Fatty Acids; Population; Pregnancy; Public Health; Reporting; Research; Research Personnel; Risk; Sampling; Schools; Selenium; Seychelles; Source; Surface; Symptoms; Testing; Time; Toxin; United States Environmental Protection Agency; United States Food and Drug Administration; base; cohort; disease registry; exposed human population; global environment; memory process; mercury fumes; neurodevelopment; neurotoxic; nutrition; postnatal; prenatal; prenatal exposure; programs; research study; restoration; vapor

DESCRIPTION (provided by applicant): Mercury (Hg) vapor and monomethylmercury (MeHg) are separately potent neurotoxins. Dental amalgam restorations, which are composed of approximately 50% metallic Hg, are the principal source of human exposure to Hg vapor, while most exposure to MeHg comes from fish consumption. Both forms of Hg cross the placental and blood-brain barriers, exposing the developing fetus. Of significant concern, the human fetus appears especially vulnerable to MeHg. There is a paucity of data on the developmental effects of prenatal Hg vapor exposure, and no data on the combined exposure to Hg vapor and MeHg exposure, despite concerns that combined exposure may elevate risk via additive or synergistic mechanisms. The proposed study will build on the strength of the Seychelles Child Development Nutrition Study (SCDNS), a longitudinal cohort study examining the association between prenatal exposure to MeHg, nutritional status, and development. Residents of the Seychelles have free dental care using amalgams and consume large quantities of ocean fish. SCDNS children have been evaluated eight times and their nutritional and developmental status to date has been well characterized. Prenatal and postnatal exposure to MeHg to date has been determined by periodic sampling of the mother's/child's hair and maternal dental status during pregnancy was established by oral examinations following delivery. In the proposed study, we will conduct routine dental exams in children recording amalgam restorations placed/present/lost as a measure of postnatal Hg vapor exposure and hair analysis as a measure of postnatal MeHg exposure. Neurodevelopmental testing will occur at 72 and 96 months. Preliminary data from a prior Seychelles cohort suggests an adverse association when Hg vapor exposure (as measured by maternal amalgams present during gestation) is included in analyses. The aim of the proposed project is to capitalize on the availability of the already well-characterized SCDNS cohort to quantify the level of risk for adverse neurodevelopmental outcomes attributable to prenatal and postnatal co-exposure to Hg vapor and MeHg. Three hypotheses will be tested: 1) The level of risk for adverse neurodevelopmental outcomes will be accentuated by combined exposure to Hg vapor and MeHg; 2) Effects of prenatal exposure will be accentuated by postnatal exposure; and 3) Overall exposure effects will be modulated by prenatal nutritional factors.

描述（由申请人提供）：汞（Hg）蒸气和一甲基汞（MeHg）分别是强效神经毒素。牙科汞合金的汞含量约为50%，是人类接触汞蒸气的主要来源，而甲基汞的大部分接触来自食用鱼类。这两种形式的汞都能穿过胎盘和血脑屏障，使发育中的胎儿暴露在外。值得关注的是，人类胎儿似乎特别容易受到甲基汞的影响。关于产前汞蒸气暴露对发育影响的数据很少，也没有关于汞蒸气和甲基汞联合暴露的数据，尽管人们担心联合暴露可能会通过叠加或协同机制增加风险。拟议的研究将借鉴塞舌尔儿童发育营养研究的成果，该研究是一项纵向队列研究，旨在研究产前接触甲基汞、营养状况和发育之间的关系。塞舌尔居民使用汞合金进行免费牙科护理，并食用大量海洋鱼类。SCDNS儿童已经接受了八次评估，迄今为止他们的营养和发育状况得到了很好的描述。到目前为止，产前和产后接触甲基汞的情况是通过定期对母亲/儿童的头发进行取样来确定的，而母亲在怀孕期间的牙齿状况则是通过分娩后的口腔检查来确定的。在拟议的研究中，我们将对儿童进行常规牙科检查，记录汞合金植入/存在/丢失情况，作为衡量出生后汞蒸气暴露的指标，并对头发进行分析，作为衡量出生后甲基汞暴露的指标。将在72和96个月时进行神经发育测试。来自塞舌尔先前队列的初步数据表明，将汞蒸气暴露（通过妊娠期间母体汞合金的存在来衡量）纳入分析时，会产生不利影响。拟议项目的目的是利用已经得到充分表征的SCDNS队列，量化产前和产后同时接触汞蒸气和甲基汞导致的不良神经发育结果的风险水平。将检验三个假设：1）汞蒸气和甲基汞的联合暴露将加重神经发育不良后果的风险水平; 2）出生后暴露将加重产前暴露的影响; 3）产前营养因素将调节总体暴露影响。