Source-specific multi-pollutant exposures and the neighborhood context in disparities in stillbirth

摘要 产科结果中的种族和民族差异的起源似乎不是遗传的，也没有得到充分的解释 由个人层面的因素决定。因此，我们必须着眼于更广泛的背景下，在物理，社会和建筑 环境，以了解和减少孕产妇和儿童健康的差距。在身体上，社会上， 环境、空气污染、邻里劣势和住宅绿化可能发挥重要作用。作为 与低出生体重、胎儿生长受限和早产相比，对空气的了解要少得多。 污染暴露对死产的影响，死产定义为在出生后20周或之后发生的宫内胎儿死亡。 怀孕城市空气污染是颗粒物和气体污染物的复杂混合物，通常相互关联， 它们受到附近常见辐射源和气象学的影响，因此，同时研究暴露 对多种空气污染物来说是一个挑战。先前关于空气污染与死产风险的研究 暴露主要集中在污染物的具体影响，包括我们的研究检查臭氧和金属 美国第四大城市PM的组成部分，德克萨斯州，休斯顿。使用源分配法评估 空气污染物暴露利用了空气污染物混合物的高度相关性， 不同来源类别的贡献，并提供信息，使更有针对性的控制战略 有待开发。到目前为止，我们知道只有一项研究，适用于细颗粒物源解析 它使用了正矩阵因子分解（PMF）受体建模。然而，这项调查使用了 估计源贡献，就像它们是真实暴露，而不考虑空间未对准误差 和方法本身固有的不确定性。针对这些不足，我们将采用创新的 将贝叶斯空间多变量受体模型（BSMRM）与土地利用和交通数据相结合的方法 以及考虑到健康影响估计中的暴露测量误差。就像空气污染一样， 和建筑环境聚集了对健康产生不利影响的邻里水平的暴露。这些压力源是 在遭受所谓“双重危险”的少数群体和低收入人口中，这种情况往往更严重。 拟议研究的目标有三个方面。首先，我们希望评估特定来源的影响， 死产的多污染物暴露，采用创新方法，将BSMRM与土地使用和 交通数据和健康影响估计中暴露测量误差的核算。我们假设 空气污染物源分配浓度的增加将与死产风险的增加有关， 不同来源类别的效应大小不同。第二，我们希望研究 关于死胎风险的邻里背景。第三，考虑到国家卫生研究院和国家的健康差距， 另一个目标是评估少数民族将遭受不成比例的死产风险的假设， 与空气污染源分摊浓度和生活在贫困社区，如评估 邻里劣势和居住区绿化。

ABSTRACT The origin of racial and ethnic disparities in obstetric outcomes does not appear to be genetic nor fully explained by individual-level factors. Hence, we must look toward the broader context in the physical, social and built environments to understand and mitigate disparities in maternal and child health. In the physical, social and built environments, air pollution, neighborhood disadvantage, and residential greenness may play important roles. As compared to low birth weight, fetal growth restriction and preterm birth, considerably less is known about air pollution exposure's impact on stillbirth, defined as an intrauterine fetal death that occurs at or after 20 weeks of gestation. Urban air pollution is a complex mixture of particle and gaseous pollutants, often correlated because they are influenced by common nearby sources and meteorology and thus, simultaneously studying exposure to multiple air pollutants is challenging. Previous studies on the risk of stillbirth associated with air pollution exposure have largely focused on pollutant-specific effects, including our studies examining ozone and metal constituents of PM in the fourth largest city in the U.S., Houston, Texas. Using source apportionment to assess air pollutant exposures takes advantage of the highly correlated nature of the air pollutant mixture, quantifies the contributions of different source categories and provides information that allows more targeted control strategies to be developed. To date, we are aware of only one study that applied source apportionment for fine particulate matter, and it used the Positive Matrix Factorization (PMF) receptor modeling. Yet, that investigation used estimated source contributions as if they were true exposures without accounting for spatial misalignment error and inherent uncertainty in the method itself. Addressing these shortcomings, we will apply an innovative approach that integrates Bayesian spatial multivariate receptor models (BSMRM) with land-use and traffic data as well as accounting for exposure measurement errors in health effects estimation. Like air pollution, the social and built environments cluster neighborhood-level exposures that adversely impact health. These stressors are often greater among minority and low-income populations who suffer what has been termed “double jeopardy”. The objective of the proposed study is three-fold. First, we wish to evaluate the impact of source-specific multipollutant exposures on stillbirth using an innovative approach that integrates BSMRM with land-use and traffic data and accounting for exposure measurement errors in health effects estimation. We hypothesize that increased air pollutant source-apportioned concentrations will be associated with increased risk of stillbirth and that effect sizes will be different for different source categories. Second, we wish to examine the impact of the neighborhood context on risk of stillbirth. Third, given the priority of health disparities for the NIH and the nation, another objective is to evaluate the hypothesis that minorities will suffer disproportionate stillbirth risks associated with air pollutant source-apportioned concentrations and with living in deprived neighborhoods, as assessed by neighborhood disadvantage and residential greenness.