Shmool Jessie L C, Bobb Jennifer F, Ito Kazuhiko, Elston Beth, Savitz David A, Ross Zev, Matte Thomas D, Johnson Sarah, Dominici Francesca, Clougherty Jane E
Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA.
Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.
Environ Res. 2015 Oct;142:624-32. doi: 10.1016/j.envres.2015.08.019.
Numerous studies have linked air pollution with adverse birth outcomes, but relatively few have examined differential associations across the socioeconomic gradient. To evaluate interaction effects of gestational nitrogen dioxide (NO2) and area-level socioeconomic deprivation on fetal growth, we used: (1) highly spatially-resolved air pollution data from the New York City Community Air Survey (NYCCAS); and (2) spatially-stratified principle component analysis of census variables previously associated with birth outcomes to define area-level deprivation. New York City (NYC) hospital birth records for years 2008-2010 were restricted to full-term, singleton births to non-smoking mothers (n=243,853). We used generalized additive mixed models to examine the potentially non-linear interaction of nitrogen dioxide (NO2) and deprivation categories on birth weight (and estimated linear associations, for comparison), adjusting for individual-level socio-demographic characteristics and sensitivity testing adjustment for co-pollutant exposures. Estimated NO2 exposures were highest, and most varying, among mothers residing in the most-affluent census tracts, and lowest among mothers residing in mid-range deprivation tracts. In non-linear models, we found an inverse association between NO2 and birth weight in the least-deprived and most-deprived areas (p-values<0.001 and 0.05, respectively) but no association in the mid-range of deprivation (p=0.8). Likewise, in linear models, a 10 ppb increase in NO2 was associated with a decrease in birth weight among mothers in the least-deprived and most-deprived areas of -16.2g (95% CI: -21.9 to -10.5) and -11.0 g (95% CI: -22.8 to 0.9), respectively, and a non-significant change in the mid-range areas [β=0.5 g (95% CI: -7.7 to 8.7)]. Linear slopes in the most- and least-deprived quartiles differed from the mid-range (reference group) (p-values<0.001 and 0.09, respectively). The complex patterning in air pollution exposure and deprivation in NYC, however, precludes simple interpretation of interactive effects on birth weight, and highlights the importance of considering differential distributions of air pollution concentrations, and potential differences in susceptibility, across deprivation levels.
众多研究已将空气污染与不良出生结局联系起来，但相对较少有研究考察社会经济梯度上的差异关联。为评估孕期二氧化氮（NO₂）与地区层面社会经济剥夺对胎儿生长的交互作用，我们使用了：（1）来自纽约市社区空气调查（NYCCAS）的高空间分辨率空气污染数据；以及（2）对先前与出生结局相关的人口普查变量进行空间分层主成分分析，以定义地区层面的剥夺程度。2008 - 2010年纽约市（NYC）医院的出生记录仅限于非吸烟母亲的足月单胎分娩（n = 243,853）。我们使用广义相加混合模型来检验二氧化氮（NO₂）与剥夺类别对出生体重的潜在非线性交互作用（并估计线性关联，以供比较），同时调整个体层面的社会人口学特征，并对共污染物暴露进行敏感性测试调整。估计的NO₂暴露水平在居住在最富裕普查区的母亲中最高且变化最大，在居住在中等剥夺程度普查区的母亲中最低。在非线性模型中，我们发现，在剥夺程度最低和最高的地区，NO₂与出生体重呈负相关（p值分别<0.001和0.05），但在中等剥夺程度范围内无关联（p = 0.8）。同样，在线性模型中，NO₂每增加10 ppb，在剥夺程度最低和最高地区的母亲中，出生体重分别下降16.2克（95% CI：-21.9至-10.5）和11.0克（95% CI：-22.8至0.9），而在中等剥夺程度地区出生体重变化不显著[β = 0.5克（95% CI：-7.7至8.7）]。剥夺程度最高和最低的四分位数中的线性斜率与中等剥夺程度（参照组）不同（p值分别<0.001和0.09）。然而，纽约市空气污染暴露和剥夺的复杂模式使得难以简单解释其对出生体重的交互作用，并突出了考虑空气污染浓度的差异分布以及不同剥夺水平下易感性潜在差异的重要性。
