Aziz Nabeel, Stafoggia Massimo, Stephansson Olof, Roos Nathalie, Kovats Sari, Chersich Matthew, Filippi Veronique, Part Cherie, Nakstad Britt, Hajat Shakoor, Ljungman Petter, de Bont Jeroen
Institute of Environmental Medicine, Karolinska Institutet, Sweden.
Institute of Environmental Medicine, Karolinska Institutet, Sweden; Department of Epidemiology, Lazio Region Health Service, ASL Roma 1, Italy.
Int J Hyg Environ Health. 2024 Sep;262:114443. doi: 10.1016/j.ijheh.2024.114443. Epub 2024 Aug 18.
Air pollution exposure has been linked with increased risk of preterm birth, which is one of the leading causes of infant mortality. Limited studies have attempted to explore these associations in low-polluted areas. In this study, we aimed to assess the association between short-term exposure to ambient air pollution and preterm birth in Sweden.
In this population-based study we included preterm births between 2014 and 2019 from the Swedish Pregnancy Register. We applied a spatiotemporal model to estimate daily levels of particulate matter <2.5 μm (PM), PM < 10 μm (PM), nitrogen dioxide (NO and ozone (O) at the residential address of each participant. We applied a time-stratified case-crossover design with conditional logistic regression analysis to estimate odds ratios (OR) of preterm birth per 10 μg/m (PM, NO, O) and 5 μg/m (PM) increase in air pollution exposure at 0-6-day lag. Two-pollutant models were applied to evaluate the independent association of each exposure on preterm birth. We also stratified by maternal characteristics to identify potential effect modifiers.
28,216 (4.5%) preterm births were included. An increase in O exposure was associated with increased odds of preterm birth [OR = 1.06 per 10 μg/m (95% CI, 1.02; 1.10]. PM and PM were not significantly associated with preterm birth, and NO displayed a negative nonlinear association with preterm birth. We did not observe any notable effect modification, but we found suggestive larger associations between O and preterm birth when stratifying by male sex, spontaneous delivery, and spring season.
Increased O exposure one week before delivery was associated with an increased risk of preterm birth in Sweden, a country with levels of air pollution below the current World Health Organization air quality guidelines. Increases in O levels with climate change make these findings especially concerning.
暴露于空气污染与早产风险增加有关，早产是婴儿死亡的主要原因之一。仅有有限的研究试图在低污染地区探究这些关联。在本研究中，我们旨在评估瑞典短期暴露于环境空气污染与早产之间的关联。
在这项基于人群的研究中，我们纳入了瑞典妊娠登记处2014年至2019年期间的早产病例。我们应用时空模型来估计每位参与者居住地址处的细颗粒物（PM₂.₅）、可吸入颗粒物（PM₁₀）、二氧化氮（NO₂）和臭氧（O₃）的每日水平。我们采用时间分层病例交叉设计并结合条件逻辑回归分析，以估计在0至6天滞后时，空气污染暴露每增加10μg/m³（PM₂.₅、NO₂、O₃）和5μg/m³（PM₁₀）时早产的比值比（OR）。应用双污染物模型来评估每种暴露与早产之间的独立关联。我们还按母亲特征进行分层，以确定潜在的效应修饰因素。
共纳入28216例（4.5%）早产病例。臭氧暴露增加与早产几率增加相关[每10μg/m³增加时OR = 1.06（95%CI，1.02；1.10）]。PM₂.₅和PM₁₀与早产无显著关联，NO₂与早产呈负非线性关联。我们未观察到任何显著的效应修饰，但在按男性性别、自然分娩和春季分层时，发现臭氧与早产之间的关联有增大的趋势。
在瑞典这个空气污染水平低于当前世界卫生组织空气质量指南的国家，分娩前一周臭氧暴露增加与早产风险增加有关。随着气候变化臭氧水平升高，这些发现尤其令人担忧。
