Impact of Air Pollution Reductions during the Beijing Olympics on Pre-term birth

北京奥运会期间空气污染减少对早产的影响

• 批准号: 8118847
• 负责人: DAVID Quincy RICH
• 金额: $ 29.33万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8118847
• 关键词: Acute; Adult; Air; Air Pollution; Aromatic Polycyclic Hydrocarbons; Automobile Driving; Biological Markers; Birth; Birth Rate; Birth Weight; Body Weight Changes; Caliber; Carbon; Carbon Monoxide; Chemicals; Child; Chinese People; Cities; Country; Coupling; Data; Elements; Evaluation; Fetal Growth Retardation; Fetus; Funding; Future; Government; Health; Health Benefit; Human; Individual; Inorganic Sulfates; Intervention; Ions; Measurement; Measures; Metals; Monitor; Morbidity - disease rate; Mothers; National Institute of Environmental Health Sciences; Natural experiment; Nitrates; Nitrogen Dioxide; Outcome; Outcome Study; Ozone; Particulate Matter; Pollution; Pregnancy; Premature Birth; Public Health; Reporting; Reproductive Health; Research Personnel; Respiratory physiology; Risk; Risk Estimate; Risk Factors; Sample Size; Series; Site; Source; Steel; Sulfur Dioxide; Term Birth; Time; Unspecified or Sulfate Ion Sulfates; Utah; adverse outcome; ammonium nitrate; base; data registry; design; improved; mortality; perinatal health; pollutant; pregnant; prenatal; prevent; public health relevance; reproductive; respiratory; response

DESCRIPTION (provided by investigator): Recent studies have provided some evidence of an association between air pollution and adverse birth outcomes including preterm delivery and fetal growth restriction. However, these studies have been inconsistent in both the pollutant(s) most consistently associated with the adverse birth outcome, and the time windows during pregnancy when pollutant concentrations are associated with these adverse outcomes. Reviews have suggested the use of 'natural experiments', studies of large and drastic changes in air pollution in a city or region that allow a more controlled evaluation of any association between a health outcome and ambient air pollution levels. We propose to take advantage of the natural experiment in Beijing during the 2008 Summer Olympics where air pollution levels were drastically reduced for a 6 week period, and then allowed to return to near Pre-Olympic levels after the games. We will examine whether these pollutant reductions were associated with decreases in the preterm birth rate and increases in birth weight. This short time window of reduced pollutant levels will allow us to isolate smaller periods of pregnancy than possible in previous studies, in order to more critically evaluate potential pregnancy periods when the fetus may be susceptible to air pollution. In a current study in central Beijing, our group is examining several hypothesized mechanisms of air pollution cardio-respiratory health effects by assessing pollution associated changes in multiple biomarkers. For this study, based on the same natural experiment, we have measured ambient concentrations of PM2.5, chemical constituents of PM2.5 including ions (e.g. sulfate, nitrate, and ammonium), elemental carbon, organic carbon, 24 elements (mainly metals), 14 PAHs,, and several gaseous pollutants before, during, and after the Olympic period. We have observed 31 percent-59 percent declines in pollutant concentrations from before to during the Olympics (e.g. mean PM2.5 declined from 104 to 65 5g/m3) and 19 percent-190 percent increases after the Olympics. We propose to use these same pollutant data, as well as PM10, NO2, and SO2 concentrations measured across Beijing at multiple stations, and birth registry data for a 3 year period from 5 adjacent Beijing districts. We will examine whether there were significant changes in the preterm birth rate and mean term birth weight, comparing the 2008 Olympic period to the same period in 2007. We will estimate the risk of preterm birth and change in term birth weight associated with changes in pollutant concentrations throughout pregnancy. The proposed analyses, with better control of confounding due to the 'natural experiment' design, will improve our limited understanding of the pregnancy times during which pollution may exert its influence on perinatal health and will also, for the first time, explore whether specific PM constituents may be responsible for these adverse birth outcome associations. The findings should help develop public health strategies to reduce these risks. PUBLIC HEALTH RELEVANCE: This project will examine the reproductive health benefit of the large and drastic air pollution reductions observed during the 2008 Beijing Summer Olympics. By studying the association between preterm birth, birth weight, and changes in the concentrations of several pollutants before, during, and after the Olympic games, the project should provide a more complete picture of the pregnancy times during which pollution may exert its influence on preterm birth and birth weight, a more comprehensive understanding of the specific pollutants and sources responsible for these associations than has been possible in previous studies, and better control of confounding due to the 'natural experiment' design.

描述（由研究者提供）：最近的研究提供了一些证据，证明空气污染与不良出生结局（包括早产和胎儿生长受限）之间存在关联。然而，这些研究在与不良出生结局最相关的污染物以及妊娠期间污染物浓度与这些不良结局相关的时间窗方面都不一致。评论建议使用“自然实验”，研究城市或地区空气污染的巨大和剧烈变化，以便对健康结果与环境空气污染水平之间的任何关联进行更可控的评估。我们建议利用2008年夏季奥运会期间在北京进行的自然实验，空气污染水平在6周内大幅降低，然后在奥运会结束后恢复到接近奥运会前的水平。我们将研究这些污染物的减少是否与早产率的降低和出生体重的增加有关。这种污染物水平降低的短时间窗口将使我们能够隔离比以前研究中可能更小的怀孕期，以便更严格地评估胎儿可能易受空气污染影响的潜在怀孕期。在北京市中心的一项研究中，我们的研究小组正在通过评估污染相关的多种生物标志物的变化来研究空气污染对心肺健康影响的几种假设机制。在这项研究中，基于相同的自然实验，我们测量了PM2.5的环境浓度，PM2.5的化学成分，包括离子（如硫酸盐，硝酸盐和铵），元素碳，有机碳，24种元素（主要是金属），14种多环芳烃，和几种气态污染物之前，期间和之后的奥运会期间。我们观察到，奥运会期间的污染物浓度比奥运会前下降了31%-59%（例如，PM2.5平均值从104下降到65 5g/m3），奥运会后增加了19%-190%。我们建议使用这些相同的污染物数据，以及在北京多个站点测量的PM10，NO2和SO2浓度，以及北京5个相邻地区3年的出生登记数据。我们将研究2008年奥运会期间与2007年同期相比，早产率和平均足月出生体重是否有显著变化。我们将估计早产的风险和与整个怀孕期间污染物浓度变化相关的足月出生体重变化。拟议的分析，更好地控制由于“自然实验”设计的混杂，将提高我们有限的了解怀孕期间，污染可能会对围产期健康产生影响，也将首次探讨是否特定的PM成分可能是负责这些不良的出生结果协会。这些发现应该有助于制定公共卫生战略，以减少这些风险。 公共卫生相关性：该项目将审查2008年北京夏季奥运会期间观察到的大规模大幅减少空气污染对生殖健康的好处。通过研究早产、出生体重与奥运会前、奥运会期间和奥运会后几种污染物浓度变化之间的关系，该项目应能更全面地了解污染可能对早产和出生体重产生影响的怀孕时间，比以往的研究更全面地了解造成这些关联的具体污染物和来源，以及由于“自然实验”设计而更好地控制混杂。