Methyl Mercury Effects on Adolescent Development

说明(申请人提供)：本提案是项目#5-R01ES08442的竞争性更新，题为甲基汞的发育毒性，测试儿童不良发育结果与食用高鱼类饮食中的甲基汞(MeHg)有关的假设。自以来，塞舌尔儿童发展研究一直在跟踪跟踪711名母亲所生的孩子，这些母亲在怀孕期间平均每周食用12份鱼粉。孩子们现在都是青少年了。食用鱼类而接触甲基汞是否会对儿童和青少年的发育产生不利影响的问题已引起公众的日益关注。对产前暴露的重视留下了几个重要的科学问题没有得到解决。暴露不会在出生时停止，但我们对出生后饮食暴露于鱼类消费中的甲基汞的长期影响知之甚少。此外，对于出生前和出生后联合暴露于甲基汞对长期结果的贡献，几乎一无所知。目前的建议旨在确定产前和产后联合暴露的后果，特别是对儿童成熟后可能出现的长期或延迟影响的影响。我们将考察三个主要发育领域的功能：复杂认知、感觉和神经运动功能，以及青春期的社会行为结果。SCDS队列将在他们15岁时接受一次检查，并在他们17岁时使用心理和神经测试和调查相结合的方式进行第二次检查。产前暴露于甲基汞是通过从注册时收集的母亲头发中的冷蒸气原子吸收来确定的。我们将继续在每次访问时收集儿童头发(就像过去五次访问中的每一次一样)，以估计不同年龄段的出生后平均暴露和最近的暴露。多元回归分析将用于评估产前和产后暴露与每个终点之间的关系。如果我们在青春期发现甲基汞的迟发性神经毒性效应，我们需要在解释产前和出生后接触甲基汞与后来健康后果的轨迹之间的联系方面做出实质性甚至根本的改变。

DESCRIPTION (provided by applicant): This proposal is a competing renewal of Project #5-R01ES08442, entitled Developmental Toxicity of Methyl Mercury, testing the hypothesis that adverse developmental outcomes in children are associated with exposure to methyl mercury (MeHg) from consumption of a diet high in fish. Since 1989, the Seychelles Child Development Study (SCDS) has been following a cohort of 711 children born to mothers who consumed an average of 12 fishmeals per week during pregnancy. The children are now adolescents. The question of whether exposure to MeHg from fish consumption adversely affects child and adolescent development has aroused deepening public concern. The emphasis on prenatal exposures has left several important scientific questions unresolved. Exposure does not cease at birth, yet we know little about the long-term effects of postnatal dietary exposure to MeHg from fish consumption. Also, almost nothing is known about the contributions to long-term outcomes of combined prenatal and postnatal exposure to MeHg. The current proposal aims to determine the consequences of combined prenatal and postnatal exposure especially for long-term or delayed effects that might appear as the children mature. We will examine functions within three major developmental domains: complex cognition, sensory and neuromotor functions, and social behavioral outcomes in adolescence. The SCDS cohort will be examine once when they are 15 years old and the second when they are 17 years using a combination of psychological and neurological tests and surveys. Prenatal exposure to MeHg was determined by cold vapor atomic absorption from maternal hair collected at enrollment. We will continue to collect child hair at each visit (as has occurred for each of the past five visits) to estimate both average postnatal exposure across ages, and recent exposure. Multiple regression analyses will be used to assess associations between prenatal and postnatal exposure and each endpoint. If we find delayed neurotoxic effects of MeHg in adolescence, substantial or even radical modifications would be required in how we interpret associations between prenatal and postnatal exposure to MeHg and the trajectory of later health consequences.