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: 7947396
• 负责人: DAVID Quincy RICH
• 金额: $ 35.14万
• 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/7947396
• 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; Natural experiment; Nitrates; Nitrogen Dioxide; Outcome; Outcome Study; Ozone; Particulate Matter; Pollution; Pregnancy; Premature Birth; Public Health; Registries; 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; 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(由研究人员提供)：最近的研究提供了一些证据，表明空气污染与包括早产和胎儿生长受限在内的不良生育结果之间存在关联。然而，这些研究在污染物(S)与不良分娩结局最一致的相关方面，以及在怀孕期间污染物浓度与这些不良结局相关的时间窗口方面，都是不一致的。有评论建议使用“自然实验”，即对一个城市或地区的空气污染进行大规模和剧烈变化的研究，以便更有控制地评估健康结果和环境空气污染水平之间的任何联系。我们计划利用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下降和出生体重的增加有关。污染物水平降低的这一短时间窗口将使我们能够分离出比之前研究中可能的更短的妊娠期，以便更严格地评估胎儿可能容易受到空气污染的潜在妊娠期。在目前北京市中心的一项研究中，我们团队正在通过评估多个生物标志物中与污染相关的变化来检验空气污染对心肺健康影响的几个假想机制。在这项研究中，我们在同一自然实验的基础上，测量了奥运会期间之前、期间和之后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种多环芳烃以及几种气态污染物。我们观察到，从奥运会前到奥运会期间，污染物浓度下降了31%-59%(例如，平均PM2.5从104克/立方米下降到65.5g/立方米)，奥运会后上升了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个邻近地区3年的出生登记数据。我们将通过比较2008年奥运会期间和2007年同期，检查早产率和平均足月出生体重是否发生了显著变化。我们将评估与孕期污染物浓度变化相关的早产风险和足月出生体重变化。拟议中的分析更好地控制了自然实验设计造成的混淆，将改善我们对污染可能对围产期健康产生影响的怀孕时间的有限理解，并将首次探索特定的PM成分是否可能导致这些不利的出生结果关联。这些发现应该有助于制定公共卫生战略，以降低这些风险。 与公共健康相关：该项目将研究2008年北京夏季奥运会期间观察到的大幅减少空气污染对生殖健康的好处。通过研究早产、出生体重和奥运会之前、期间和之后几种污染物浓度变化之间的联系，该项目应该能够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，比以前的研究更全面地了解导致这些联系的特定污染物和来源，并更好地控制由于“自然实验”设计造成的混乱。