College of Environmental Sciences and Engineering and Centre for Environment and Health, Peking University, Beijing, China.
Am J Respir Crit Care Med. 2012 Dec 1;186(11):1150-9. doi: 10.1164/rccm.201205-0850OC. Epub 2012 Aug 30.
Unprecedented pollution control actions during the Beijing Olympics provided a quasi-experimental opportunity to examine biologic responses to drastic changes in air pollution levels.
To determine whether changes in levels of biomarkers reflecting pulmonary inflammation and pulmonary and systemic oxidative stress were associated with changes in air pollution levels in healthy young adults.
We measured fractional exhaled nitric oxide, a number of exhaled breath condensate markers (H(+), nitrite, nitrate, and 8-isoprostane), and urinary 8-hydroxy-2-deoxyguanosine in 125 participants twice in each of the pre- (high pollution), during- (low pollution), and post-Olympic (high pollution) periods. We measured concentrations of air pollutants near where the participants lived and worked. We used mixed-effects models to estimate changes in biomarker levels across the three periods and to examine whether changes in biomarker levels were associated with changes in pollutant concentrations, adjusting for meteorologic parameters.
From the pre- to the during-Olympic period, we observed significant and often large decreases (ranging from -4.5% to -72.5%) in levels of all the biomarkers. From the during-Olympic to the post-Olympic period, we observed significant and larger increases (48-360%) in levels of these same biomarkers. Moreover, increased pollutant concentrations were consistently associated with statistically significant increases in biomarker levels.
These findings support the important role of oxidative stress and that of pulmonary inflammation in mediating air pollution health effects. The findings demonstrate the utility of novel and noninvasive biomarkers in the general population consisting largely of healthy individuals.
北京奥运会期间采取的前所未有的污染控制措施提供了一个准实验机会，可用来研究空气污染水平的剧烈变化对生物的反应。
确定反映肺部炎症和肺部及全身氧化应激的生物标志物水平的变化是否与健康年轻成年人的空气污染水平变化有关。
我们在预（高污染）、中（低污染）和后（高污染）奥运三个时期内，对 125 名参与者进行了两次测量，测量了呼出气一氧化氮分数、一些呼出气冷凝物标志物（H(+)、亚硝酸盐、硝酸盐和 8-异前列腺素）以及尿 8-羟基-2-脱氧鸟苷的水平。我们测量了参与者居住和工作地点附近的空气污染物浓度。我们使用混合效应模型来估计三个时期内生物标志物水平的变化，并检验生物标志物水平的变化是否与污染物浓度的变化有关，同时还调整了气象参数。
从预到中奥运期间，我们观察到所有生物标志物的水平都出现了显著且通常较大的下降（范围从-4.5%到-72.5%）。从中奥运到后奥运期间，我们观察到这些相同生物标志物的水平出现了显著且更大的上升（48-360%）。此外，污染物浓度的增加始终与生物标志物水平的统计学显著增加有关。
这些发现支持氧化应激和肺部炎症在介导空气污染健康影响方面的重要作用。这些发现表明，新型非侵入性生物标志物在主要由健康个体组成的普通人群中具有实用性。
