Nakhjirgan Pegah, Kashani Homa, Naddafi Kazem, Nabizadeh Ramin, Amini Heresh, Yunesian Masud
1Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Poursina Street, Keshavarz Boulevard, Tehran, 1417613151 Iran.
2Department of Research Methodology and Data Analysis, Institute for Environmental Research, Tehran University of Medical Sciences, No. 1547, North Kargar Ave, Tehran, 1417993359 Iran.
J Environ Health Sci Eng. 2019 Jun 22;17(2):711-717. doi: 10.1007/s40201-019-00386-7. eCollection 2019 Dec.
Air pollution can cause various health outcomes, especially in susceptible groups including pregnant women. Low birth weight (LBW) is among the adverse birth outcomes and is one of the main causes of infant mortality. The aim of this study was to assess the association between air pollutants and LBW in Tehran, Iran.
In this case-control study, 2144 babies born in three hospitals of Tehran (Iran) during 2011 to 2012 whose mothers were the residents of this city in last 5 years were considered. Of these, 468 infants with birth weight < 2500 g and 1676 with birth weight ≥ 2500 g were regarded as case and control groups, respectively. Gestational age was also considered for definition of cases (small for gestational age (SGA)) and controls (appropriate for gestational age). Land use regression models were used to assess exposure to particulate matter ≤10 μm in aerodynamic diameter (PM), sulfur dioxide (SO), nitrogen dioxide (NO) and volatile organic compounds (benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene (BTEX), and total BTEX) during pregnancy. Logistic regression model was applied to assess the association between air pollutants and LBW.
The concentrations of air pollutants were very high but similar in cases and controls. After adjustment for potential confounding variables, no statistically significant association was observed between air pollutants and LBW. The adjusted odds ratios (95% confidence interval) for PM, SO, and benzene were 0.999 (0.994-1.005), 0.998 (0.993-1.003), and 0.980 (0.901-1.067), respectively.
No association was found between LBW and air pollutants. Further studies with more rigorous designs and access to more comprehensive information are suggested to assess the effect of other air pollutants, such as CO, O, PM, ultrafine particles, and oxidative potential of particles on birth outcomes.
空气污染会导致各种健康问题，尤其是在包括孕妇在内的易感人群中。低出生体重是不良出生结局之一，也是婴儿死亡的主要原因之一。本研究的目的是评估伊朗德黑兰空气污染物与低出生体重之间的关联。
在这项病例对照研究中，纳入了2011年至2012年期间在德黑兰（伊朗）的三家医院出生、其母亲在过去5年是该市居民的2144名婴儿。其中，468名出生体重<2500克的婴儿和1676名出生体重≥2500克的婴儿分别被视为病例组和对照组。病例（小于胎龄儿（SGA））和对照组（适于胎龄儿）的定义也考虑了孕周。采用土地利用回归模型评估孕期空气中空气动力学直径≤10μm的颗粒物（PM）、二氧化硫（SO）、二氧化氮（NO）和挥发性有机化合物（苯、甲苯、乙苯、邻二甲苯、间二甲苯、对二甲苯（BTEX）以及总BTEX）的暴露情况。应用逻辑回归模型评估空气污染物与低出生体重之间的关联。
空气污染物浓度很高，但病例组和对照组相似。在对潜在混杂变量进行调整后，未观察到空气污染物与低出生体重之间存在统计学显著关联。PM、SO和苯的调整后比值比（95%置信区间）分别为0.999（0.994 - 1.005）、0.998（0.993 - 1.003）和0.980（0.901 - 1.067）。
未发现低出生体重与空气污染物之间存在关联。建议开展设计更严谨、能获取更全面信息的进一步研究，以评估其他空气污染物，如一氧化碳、臭氧、细颗粒物、超细颗粒物以及颗粒物的氧化潜能对出生结局的影响。
