Postnatal Methylmercury Effects on Neurodevelopment

儿童时期食用鱼类导致的甲基汞(MeHg)暴露可能对发育产生不利影响 结果。大脑直到生命的第三个十年的一半才完全发育，因此 可能在胎儿期以后很容易受到甲基汞的影响。目前还不知道它是否安全 孩子们吃鱼。虽然流行病学证据支持出生后接触甲基汞的假设 与儿童发育有不利关联的研究没有专门设计用于研究 出生后接触甲基汞。几乎所有的研究都是对甲基汞暴露的横断面评估 仅在认知测试时测量(便利样本)。目前还没有研究采用 更明确和更有效的方法纵向评估出生后甲基汞暴露与 儿童和青春期的认知结果。我们有能力研究这个问题。 纵向上在塞舌尔共和国，那里的饮食甲基汞暴露是世界上最高的之一。在……里面 1989-1990年，我们招募了779对母婴(“主要队列”)的前瞻性队列。我们有24年的时间 在这个队列中，出生后暴露和神经发育数据已经被更多地表征 比其他任何群体都要广泛。在横断面分析中，我们发现 近期出生后暴露于甲基汞和不同年龄的不同发育终点，尤其是 在9岁和9岁时测量精神运动和执行功能、注意力和一般智力 年纪更大了。这些认知领域在出生后有最大的发展，因此更有可能 受出生后接触甲基汞的影响。这些耐人寻味的结果需要用纵向分析来研究 这更好地解决了出生后暴露的可变性及其随着时间的推移对神经发育的影响。这个 这项拟议的研究的目的是检验出生后累积的甲基汞的纵向联系 暴露在神经发育中。我们假设，较大的出生后累积暴露是 与儿童和青春期后期的神经发育结果呈负相关。我们将使用 先前开发的基于重复测量儿童头发甲基汞的累积暴露量 价值观。到目前为止，这一指标仅与9岁时的一个发育结果有关。 我们现在有关于这个队列的额外15年的暴露和发育数据。我们将利用 这些数据并检查三个累积的出生后暴露指标(早期生活、青春期晚期和终生) 与在横断面分析中显示出不利关联的认知领域有关。纵向 随着时间的推移，模型将评估关联的一致性。数十亿人每天依赖于 鱼的营养特性。因此，至关重要的是要检查儿童是否从 食用鱼类与不利的发育后果有关。这项研究将提供最多 迄今为止，对儿童食用鱼类的风险或安全性进行了全面评估。

Methylmercury (MeHg) exposure from fish consumption during childhood may adversely affect developmental outcomes. The brain is not fully developed until halfway through the third decade of life and is therefore potentially susceptible to MeHg exposure well beyond the fetal period. It is currently not known if it is safe for children to eat fish. While epidemiological evidence supports the hypothesis that postnatal MeHg exposure is adversely associated with children's development, studies have not been specifically designed to study postnatal MeHg exposure. Nearly all studies have been cross-sectional evaluations in which MeHg exposure was measured only at the time of cognitive testing (convenience samples). No studies have employed the more definitive and powerful approach of longitudinal assessment of postnatal MeHg exposure in relation to cognitive outcomes throughout childhood and adolescence. We are in a position to study this issue longitudinally in the Republic of Seychelles where dietary MeHg exposure is among the highest in the world. In 1989-90 we enrolled a prospective cohort of 779 mother-infant pairs (“Main Cohort”). We have 24 years of postnatal exposure and neurodevelopmental data in this cohort, which has been characterized more extensively than any other cohort. In cross-sectional analyses we have found adverse associations between recent postnatal MeHg exposure and various developmental endpoints at different ages, but especially with measures of psychomotor and executive function, attention, and general intelligence at 9 years of age and older. These cognitive domains have their greatest development postnatally and are therefore more likely to be affected by postnatal MeHg exposure. These intriguing results need to be studied using longitudinal analyses that better address the variability in postnatal exposure and its impact on neurodevelopment over time. The aim of this proposed study is to examine the longitudinal associations of cumulative postnatal MeHg exposure with neurodevelopment. We hypothesize that greater accumulated postnatal exposure is adversely associated with neurodevelopmental outcomes in later childhood and adolescence. We will use a previously-developed cumulative exposure metric based on repeated measurement of children's hair MeHg values. So far, this metric has only been examined in relation to one developmental outcome at 9 years of age. We now have an additional 15 years of exposure and developmental data on this cohort. We will leverage these data and examine three cumulative postnatal exposure metrics (early life, late adolescent, and lifetime) in relation to cognitive domains that have shown adverse associations in cross-sectional analyses. Longitudinal models will evaluate the consistency of associations over time. Billions of people depend daily on the nutritional properties of fish. It is therefore critical to examine whether children's exposure to MeHg from consumption of fish is associated with adverse developmental consequences. This study will provide the most comprehensive assessment to date of the risks or safety of fish consumption in childhood.