Rich David Q, Liu Kaibo, Zhang Jinliang, Thurston Sally W, Stevens Timothy P, Pan Ying, Kane Cathleen, Weinberger Barry, Ohman-Strickland Pamela, Woodruff Tracey J, Duan Xiaoli, Assibey-Mensah Vanessa, Zhang Junfeng
Department of Public Health Sciences, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA.
Environ Health Perspect. 2015 Sep;123(9):880-7. doi: 10.1289/ehp.1408795. Epub 2015 Apr 28.
Previous studies have reported decreased birth weight associated with increased air pollutant concentrations during pregnancy. However, it is not clear when during pregnancy increases in air pollution are associated with the largest differences in birth weight.
Using the natural experiment of air pollution declines during the 2008 Beijing Olympics, we evaluated whether having specific months of pregnancy (i.e., 1st…8th) during the 2008 Olympics period was associated with larger birth weights, compared with pregnancies during the same dates in 2007 or 2009.
Using n = 83,672 term births to mothers residing in four urban districts of Beijing, we estimated the difference in birth weight associated with having individual months of pregnancy during the 2008 Olympics (8 August-24 September 2008) compared with the same dates in 2007 and 2009. We also estimated the difference in birth weight associated with interquartile range (IQR) increases in mean ambient particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) concentrations during each pregnancy month.
Babies whose 8th month of gestation occurred during the 2008 Olympics were, on average, 23 g larger (95% CI: 5 g, 40 g) than babies whose 8th month occurred during the same calendar dates in 2007 or 2009. IQR increases in PM2.5 (19.8 μg/m3), CO (0.3 ppm), SO2 (1.8 ppb), and NO2 (13.6 ppb) concentrations during the 8th month of pregnancy were associated with 18 g (95% CI: -32 g, -3 g), 17 g (95% CI: -28 g, -6 g), 23 g (95% CI: -36 g, -10 g), and 34 g (95% CI: -70 g, 3 g) decreases in birth weight, respectively. We did not see significant associations for months 1-7.
Short-term decreases in air pollution late in pregnancy in Beijing during the 2008 Summer Olympics, a normally heavily polluted city, were associated with higher birth weight.
Rich DQ, Liu K, Zhang J, Thurston SW, Stevens TP, Pan Y, Kane C, Weinberger B, Ohman-Strickland P, Woodruff TJ, Duan X, Assibey-Mensah V, Zhang J. 2015. Differences in birth weight associated with the 2008 Beijing Olympics air pollution reduction: results from a natural experiment. Environ Health Perspect 123:880-887; http://dx.doi.org/10.1289/ehp.1408795.
以往研究报告称，孕期空气污染浓度增加与出生体重下降有关。然而，尚不清楚孕期空气污染增加在何时与出生体重的最大差异相关。
利用2008年北京奥运会期间空气污染下降这一自然实验，我们评估了在2008年奥运会期间怀孕的特定月份（即第1个月至第8个月）与2007年或2009年相同日期怀孕相比，是否与更大的出生体重相关。
我们利用居住在北京四个城区的母亲所生的83,672例足月分娩数据，估计了2008年奥运会期间（2008年8月8日至9月24日）怀孕各月份与2007年和2009年相同日期相比出生体重的差异。我们还估计了孕期各月份空气中平均空气动力学直径≤2.5μm的颗粒物（PM2.5）、二氧化硫（SO2）、二氧化氮（NO2）和一氧化碳（CO）浓度增加四分位间距（IQR）与出生体重差异的关联。
妊娠第8个月发生在2008年奥运会期间的婴儿，平均比2007年或2009年相同日历日期妊娠第8个月的婴儿重23克（95%可信区间：5克，40克）。妊娠第8个月时，PM2.5浓度增加IQR（19.8μg/m3）、CO浓度增加IQR（0.3ppm）、SO2浓度增加IQR（1.8ppb）和NO2浓度增加IQR（13.6ppb）分别与出生体重下降18克（95%可信区间：-32克，-3克）、17克（95%可信区间：-28克，-6克）、23克（95%可信区间：-36克，-10克）和34克（95%可信区间：-70克，3克）相关。我们未发现第1至7个月有显著关联。
在通常污染严重的城市北京，2008年夏季奥运会期间孕期后期空气污染的短期下降与出生体重增加有关。
Rich DQ, Liu K, Zhang J, Thurston SW, Stevens TP, Pan Y, Kane C, Weinberger B, Ohman-Strickland P, Woodruff TJ, Duan X, Assibey-Mensah V, Zhang J. 2015. Differences in birth weight associated with the 2008 Beijing Olympics air pollution reduction: results from a natural experiment. Environ Health Perspect 123:880-887; http://dx.doi.org/10.1289/ehp.1408795.
