超细颗粒物对上海市某区65岁以上老年人群外周血 白细胞计数影响的定群研究

目的 研究超细颗粒物（ultrafine particles, UFPs）对65岁以上老年人群外周血白细胞计数（white blood cell count, WBC）的影响。方法 招募上海市某区65岁以上老年居民,采用定群研究方法,于2014年1月1日至2018年12月29日进行至少2次健康体检,采集外周静脉血测定WBC水平;收集区域同期大气UFPs每小时粒数浓度（particle number concentration, PNC）、常规大气污染物逐日浓度和气象资料,利用线性混合效应模型分析UFPs对WBC短期变化的影响,同时对人员特征、温度、相对湿度、星期几效应及时间趋势等协变量进行控制。结果 共纳入研究对象108 006名,WBC为（6.2±1.4）×109/L。UFPs中以粒径0.05~0.10 μm颗粒物的PNC值最高,粒径0.03~0.05 μm的颗粒物次之,粒径0.01~0.03 μm颗粒物的PNC值则相对较低。Lag 01 d时,粒径范围0.01~0.03 μm、0.03~0.05 μm、0.05~0.10 μm的UFPs 和总颗粒物（0.01~0.10 μm）PNC值每增加1个IQR,WBC分别升高9.98（95% CI : 1.12~18.84）×106/L、11.88（95% CI : 2.99~20.76）×106/L、28.78（95% CI : 18.07~39.49）×106/L和20.66（95% CI : 11.09~30.23）×106/L。结论 UFPs短期暴露可导致上海市某区65岁以上老年人群炎症水平升高。

Impact of ultrafine particles on the white blood cell count of older residents aged above 65 in Shanghai: a panel study

Objective To investigate the impact of ultrafine particles (UFPs) on the white blood cell count (WBC) of older residents aged above 65 in Shanghai, China.]Methods Older residents aged above 65 in a certain district of Shanghai were recruited and underwent at least 2 physical exams of panel study from January 1 th 2014 to December 29 th 2018. The levels of blood WBC were measured at each visit. Data on ambient UFPs, routine air pollutants, and meteorologic parameters were obtained during the same period. Linear mixed models were applied to analyze the short-term effect of UFPs on WBC, after controlling for individual characteristics, temperature, relative humidity, day of the week and time-related trends.]Results A total of 108 006 study subjects were included. The average WBCwas (6.2±1.4)×10 9/L. Among UFPs, particle number concentration (PNC) for size ranges from 0.05 to 0.1 μm the highest, followed by size ranges from 0.03 to 0.05 μm, and PNC for size ranges from 0.01 to 0.03 μm was relatively low. An interquartile range increase in PNC at lag0-1 day for size ranges 0.01-0.03 μm, 0.03-0.05 μm, 0.05-0.1 μm and 0.01-0.1 μm was associated with increments of 9.98 (95%CI: 1.12-18.84)×10 6/L, 11.88 (95%CI: 2.99-20.76)×10 6/L, 28.78 (95%CI: 18.07-39.49)×10 6/L, and 20.66(95%CI: 11.09-30.23)×10 6/L in WBC, respectively.]Conclusion Short-term exposure to UFPs may significantly elevate the level of inflammation in older residents aged above 65 in Shanghai City.