Background

An association between maternal exposure to air pollution and the birth weight distribution has been reported, but the extent to which this relationship varies according to socioeconomic status (SES) is unknown. This study examined the relationship using the data from a Korean birth cohort.

Methods

Data for singleton births in Seoul from 2007 to 2017 (n = 1739) were analyzed. Maternal exposures to particulate matter with an aerodynamic diameter <10 µm (PM₁₀) and <2.5 µm (PM_2.5), as well as to nitrogen dioxide (NO₂) and ozone (O₃) for each trimester and the entire pregnancy were estimated using residential address, gestational age, and the birth date. The associations between the interquartile range (IQR) increases in pollutant concentrations and the changes in birth weight were examined using linear regression and quantile regression models. The socioeconomic disparities in the associations were investigated using a derived SES variable based on the composite of parental education and occupation. This SES variable was then interacted with the air pollutant.

Results

In the gestational age-adjusted models, particulate air pollutants (PM₁₀ and PM_2.5) and O₃ were associated with birth weight decreases for the lower birth weight percentiles. For example, the decrease in mean birthweight per IQR increase in PM_2.5 during second trimester was −21.1 g (95% confidence interval (CI) = −41.8, −0.4), whereas the quantile-specific associations were: 10th percentile −27.0 g (95% CI = −46.6, −7.3); 50th percentile −22.2 g (95% CI = −39.6, −4.8); and 90th percentile −22.9 g (95% CI = −45.5, −0.2). Particulate air pollutants and O₃ showed a pattern of socioeconomic inequalities; the reduced birth weight was of greater magnitude for children from a low SES group.

Conclusions

Negative associations between particulate air pollutants and O₃ and birth weight were consistently greater at the lower quantiles of the birth weight distribution, especially in lower SES group.

中文翻译：

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空气污染和出生体重的社会经济不平等的分位数回归分析。

背景

据报道，孕产妇暴露于空气污染与出生体重分布之间存在关联，但是这种关系根据社会经济状况（SES）的变化程度尚不清楚。这项研究使用韩国出生队列的数据检验了这种关系。

方法

分析了首尔2007年至2017年（n = 1739）的单胎出生数据。孕产妇暴露于空气动力学直径<10 µm（PM ₁₀）和<2.5 µm（PM _2.5）的颗粒物，二氧化氮（NO ₂）和臭氧（O ₃）使用居住地址，胎龄和出生日期估算每个孕期和整个妊娠。使用线性回归和分位数回归模型检查了污染物浓度的四分位数间距（IQR）增加与出生体重变化之间的关联。协会中的社会经济差异是根据父母的教育和职业综合得出的SES变量进行调查的。然后将此SES变量与空气污染物相互作用。

结果

在调整胎龄的模型中，对于较低的出生体重百分位数，空气微粒污染物（PM ₁₀和PM _2.5）和O ₃与出生体重下降有关。例如，孕中期PM _2.5的每IQR增加的平均出生体重下降为-21.1 g（95％置信区间（CI）= -41.8，-0.4），而分位数特异性关联为：第十个百分点-27.0 g （95％CI ＝ -46.6，-7.3）；第50个百分点-22.2克（95％CI = -39.6，-4.8）；和第90个百分位数-22.9 g（95％CI = -45.5，-0.2）。空气中的微粒污染物和O ₃表现出一种社会经济不平等的模式。低SES组儿童的出生体重减轻幅度更大。

结论

在出生体重分布的较低分位数处，尤其是在较低的SES组中，颗粒空气污染物与O ₃和出生体重之间的负相关性一直较大。