Effects of Fine Particle Composition on Birth Outcomes

描述(申请人提供)：早产、低出生体重和小于胎龄(SGA)是美国婴儿死亡和严重发病率的主要原因。对于非裔美国人来说，这些风险几乎翻了一番。一些研究表明，空气污染，特别是2.5毫米的颗粒物(PM2.5)是导致不良生育结局的危险因素。这项研究的一个挑战是，颗粒物的化学成分因地区和季节的不同而有很大差异。由于缺乏关于哪种类型的颗粒物危害最大的科学证据，颗粒物受到大小的限制。我们将调查颗粒物化学成分的两个方面：1)单个PM2.5化学成分(如镍)的水平；2)特定来源(如石油燃烧)的PM2.5水平，以调查接触特定类型颗粒物与出生结局之间的关系。我们从8个CT和MA监测点获得了过滤器，用于测量PM2.5总质量。我们将分析这些过滤器，以确定49种化学成分的水平。这些化学成分数据将用于来源解析模型，以估计特定来源(如机动车辆)的PM2.5。我们的主要结果将是出生体重(连续)，低出生体重和lt；2500克，极低出生体重和lt；1500克，早产和lt；37周，极早产和lt；32周，以及小于胎龄(&lt；10%胎龄体重)，使用CT和MA出生证明数据(2001-2006年)，在监测点30公里内(N=213,000)出生。将评估出生结果与PM2.5化学成分之间的关系(目标1)，以及出生结果与来自特定来源的PM2.5水平之间的关系(目标2)。在目标3中，我们将用三种暴露方法来研究交通PM2.5：1)与目标1的交通最相关的化学成分；2)目标2的交通PM2.5水平；以及3)通过地理信息系统交通模型估计与交通有关的空气污染。在我们的初步研究中，暴露于特定PM2.5成分的四分位数范围(IQR)增加，低出生体重的风险增加8-13%。我们将拥有90%的权力来检测与特定PM2.5成分或PM2.5来源的IQR变化相关的任何结局风险增加10%(包括非常低的出生体重，患病率1.5%)。将在交互模型中调查关联，以测试影响是否因种族而不同。这项研究的结果将确定PM2.5的成分或来源对出生结局的影响最大，并可能导致针对对婴儿健康最有害的来源进行干预。

DESCRIPTION (provided by applicant): Preterm delivery, low birth weight and small for gestational age (SGA) are major causes of infant mortality and severe morbidity in the U.S. For African Americans, these risks are nearly doubled. Several studies have implicated air pollution, especially particulate matter <2.5mm (PM2.5) as a risk factor for adverse birth outcomes. A challenge in this research is that particles vary widely in chemical composition by region and season. Due to lack of scientific evidence on which types of particles are most harmful, particles are regulated by size. We will investigate two aspects of the chemical composition of particles: 1) levels of individual PM2.5 chemical components (e.g., nickel); and 2) levels of PM2.5 from specific sources (e.g. oil combustion), to investigate the relationship between exposure to specific types of particles and birth outcomes. We obtained filters from 8 CT and MA monitoring sites that were used to measure PM2.5 total mass. We will analyze these filters to determine levels of 49 chemical components. This chemical component data will be used in source apportionment modeling to estimate PM2.5 from specific sources (e.g. motor vehicles). Our primary outcomes will be birth weight (continuous), low birth weight <2500 gm, very low birth weight <1500 gm, preterm birth <37 wks, very preterm birth <32 wks, and small for gestational age (<10th percentile weight for gestational age), using CT and MA birth certificate data for births (2001-2006) within 30 km of the monitoring sites (N=213,000). Associations will be assessed between birth outcomes and PM2.5 chemical components (Aim 1) and between birth outcomes and the levels of PM2.5 from particular sources (Aim 2). In Aim 3 we will examine traffic PM2.5 with three exposure methods: 1) the chemical component most associated with traffic from Aim 1; 2) traffic PM2.5 levels from Aim 2; and 3) traffic-related air pollution estimated through a GIS traffic model. In our preliminary studies, risk of low birth weight increased 8-13% per interquartile range (IQR) increase in exposure to specific PM2.5 components. We will have >90% power to detect a 10% increase in risk of any outcome (including very low birth weight, prevalence 1.5%) associated with an IQR change exposure to a specific PM2.5 component or PM2.5 source. Associations will be investigated in interaction models to test whether effects differ by race. Findings from this study will identify the components or sources of PM2.5 with the greatest impact on birth outcomes and could lead to interventions targeted at the sources most toxic to infant health.