Division of Respiratory Medicine, Department of Pediatrics, Inselspital, University of Bern, Bern, Switzerland.
J Aerosol Med Pulm Drug Deliv. 2013 Feb;26(1):9-23. doi: 10.1089/jamp.2011.0932. Epub 2012 Aug 2.
There is increasing evidence of the adverse impact of prenatal exposure to air pollution. This is of particular interest, as exposure during pregnancy--a crucial time span of important biological development--may have long-term implications. The aims of this review are to show current epidemiological evidence of known effects of prenatal exposure to air pollution and present possible mechanisms behind this process. Harmful effects of exposure to air pollution during pregnancy have been shown for different birth outcomes: higher infant mortality, lower birth weight, impaired lung development, increased later respiratory morbidity, and early alterations in immune development. Although results on lower birth weight are somewhat controversial, evidence for higher infant mortality is consistent in studies published worldwide. Possible mechanisms include direct toxicity of particles due to particle translocation across tissue barriers or particle penetration across cellular membranes. The induction of specific processes or interaction with immune cells in either the pregnant mother or the fetus may be possible consequences. Indirect effects could be oxidative stress and inflammation with consequent hemodynamic alterations resulting in decreased placental blood flow and reduced transfer of nutrients to the fetus. The early developmental phase of pregnancy is thought to be very important in determining long-term growth and overall health. So-called "tracking" of somatic growth and lung function is believed to have a huge impact on long-term morbidity, especially from a public health perspective. This is particularly important in areas with high levels of outdoor pollution, where it is practically impossible for an individual to avoid exposure. Especially in these areas, good evidence for the association between prenatal exposure to air pollution and infant mortality exists, clearly indicating the need for more stringent measures to reduce exposure to air pollution.
越来越多的证据表明，产前暴露于空气污染会产生不良影响。这一点尤其值得关注，因为怀孕期间的暴露——这是重要的生物发育关键时期——可能会产生长期影响。本综述的目的是展示当前已知产前暴露于空气污染对健康的影响的流行病学证据，并提出这一过程背后可能的机制。已经证明，孕妇暴露于空气污染会对不同的出生结果产生有害影响：婴儿死亡率增加、出生体重降低、肺部发育受损、日后呼吸道发病率增加以及免疫发育早期改变。尽管关于出生体重降低的结果存在一些争议，但全球范围内发表的研究结果都一致表明，婴儿死亡率更高。可能的机制包括颗粒的直接毒性，因为颗粒会穿过组织屏障或穿透细胞膜。也可能会出现诱导特定过程或与孕妇或胎儿中的免疫细胞相互作用的情况。间接影响可能是氧化应激和炎症，从而导致血液动力学改变，导致胎盘血流减少和向胎儿输送的营养物质减少。妊娠的早期发育阶段被认为对长期生长和整体健康非常重要。所谓的“追踪”躯体生长和肺功能，据信对长期发病率有巨大影响，特别是从公共卫生的角度来看。在户外污染水平较高的地区，这一点尤为重要，因为个人实际上不可能避免暴露于这些污染物。特别是在这些地区，产前暴露于空气污染与婴儿死亡率之间存在很强的关联证据，这清楚地表明需要采取更严格的措施来减少空气污染的暴露。
