A panel study on effects of ambient particles of different sizes and from different sources on blood pressure in healthy adults in an urban area of Beijing
招募73名健康成年志愿者，采用定组研究方法，于2014年11月-2016年1月进行了4次随访，测量血压，采集血清，测定系统性炎症标志物超敏C反应蛋白和同型半胱氨酸水平；收集研究区域同期空气动力学直径5.6~560 nm的颗粒物粒数浓度和气象资料，并利用正定矩阵因子法对5.6~560 nm共计32个不同粒径段的颗粒物进行来源解析。利用线性混合效应模型分析大气颗粒物暴露对血压的影响。
P< 0.05），即累积暴露1、2 d的二次颗粒和老化机动车颗粒每升高1个四分位间距粒数浓度，舒张压升高的均值及其95% CI分别为2.9（1.3~4.4）、2.1（0.4~3.7）mmHg和1.7（0.1~3.4）、2.9（0.6~5.1）mmHg。大气颗粒物在体质量指数≥ 25 kg·m-2、超敏C反应蛋白和同型半胱氨酸浓度水平较高的研究对象中升高血压效应更强。 结论
Air pollution has become a leading risk factor for cardiovascular diseases. Increased blood pressure is one of the possible underlying pathways. However, the effects of source-specific pollution remain incompletely understood.
This study aims to explore the associations of blood pressure in healthy adults with exposure to source-specific versus size-segregated ambient particles.
Seventy-three healthy adults were recruited for a panel study and underwent four repeated measurements from November 2014 to January 2016. Blood pressure and serum levels of systemic inflammation markers hypersensitive C-reaction protein and homocysteine were measured at each visit. Particle number concentrations of particles in size fractions of 5.6-560nm and meteorological variables in the study area were collected. The sources were identified based on PNC5.6-560 including a total of 32 size distribution segments, using the positive matrix factorization method. Linear mixed-effect models were constructed to estimate the effects of exposure to ambient particles on blood pressure in healthy adults after adjusting for selected confounders.
The five identified sources of ambient particles were gasoline vehicle emissions, aged vehicle emissions, nucleation, secondary aerosols, and others based on hourly PNC5.6-560 during the study period. The participants' diastolic blood pressure was positively associated with the exposure to the particles from secondary aerosols and aged vehicle emissions at moving average 1 and 2 days prior to clinic visit (
P< 0.05). Significant increases (mean and 95% CI) in diastolic blood pressure of 2.9 (1.3-4.4) and 2.1 (0.4-3.7) mmHg and 1.7 (0.1-3.4) and 2.9 (0.6-5.1) mmHg were associated with an interquartile range increase in the number concentrations of particles from secondary aerosols and aged vehicle emissions at moving average 1 and 2 days prior to clinic visit, respectively. Stronger associations were found between particles and increased blood pressure in participants with body mass index equal to or over 25 kg·m-2 and higher levels of serum hypersensitive C-reaction protein and homocysteine. Conclusion
Acute exposure to particles from secondary aerosols and aged vehicle emissions may increase the diastolic blood pressure in healthy adults, and ambient particles have a stronger effect on adults with overweight and a higher level of systemic inflammation.