Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China.
Shanghai Municipal Centre for Disease Control and Prevention, Shanghai, China.
J Allergy Clin Immunol. 2022 Jul;150(1):214-222.e5. doi: 10.1016/j.jaci.2021.12.779. Epub 2021 Dec 28.
Evidence concerning the effects of different chemical components of particulate matter with an aerodynamic diameter of 2.5 μm or less (PM) on asthma is limited, and the methodology to compare the relative importance of different PM components is lacking.
Our aim was to examine the associations between PM components and asthma and investigate which constituent of PM possessed the most harmful effect on asthma.
A total of 45,690 subjects in 6 countries were surveyed from 2007 to 2010. We geocoded the residential community addresses of the participants and used satellite remote sensing and chemical transport modeling to estimate their annual average concentrations of PM constituents. Mixed-effects generalized additive models were utilized to examine the associations between PM constituents and prevalence of asthma. We further used counterfactual analyses to determine the potential number of asthma cases.
We identified 6178 patients with asthma among the participants, producing an asthma prevalence of 13.5%. The odds ratio for asthma associated with per-SD increment was 1.12 for PM mass, 1.12 for organic carbon, 1.18 for black carbon, 1.19 for sulfate, 1.28 for ammonium, and 1.21 for nitrate after controlling for potential confounders. Our counterfactual analyses suggested that ammonium was responsible for a substantial decline in asthma cases (by 1382 cases, corresponding to 22.37% of overall cases) if the concentration was reduced to the 5th percentile of the current level.
Our study suggests that some chemical components of PM (including black carbon, organic carbon, sulfate, ammonium, and nitrate) might be hazardous constituents contributing to the prevalence of asthma; among them, ammonium might be responsible for a substantial proportion of asthma cases if reduced to a certain level.
关于直径小于或等于 2.5μm 的颗粒物（PM）的不同化学成分对哮喘的影响的证据有限，并且缺乏比较不同 PM 成分相对重要性的方法。
我们旨在研究 PM 成分与哮喘之间的关联，并探讨 PM 成分中哪一种对哮喘的危害最大。
我们于 2007 年至 2010 年期间在 6 个国家调查了 45690 名参与者。我们对参与者的居住社区地址进行地理编码，并使用卫星遥感和化学输送建模来估计他们每年平均的 PM 成分浓度。我们利用混合效应广义加性模型来研究 PM 成分与哮喘患病率之间的关联。我们进一步使用反事实分析来确定潜在的哮喘病例数。
我们在参与者中发现了 6178 例哮喘患者，哮喘患病率为 13.5%。与 PM 质量、有机碳、黑碳、硫酸盐、铵和硝酸盐每标准差增量相关的哮喘比值比分别为 1.12、1.12、1.18、1.19、1.28 和 1.21，在控制了潜在混杂因素后。我们的反事实分析表明，如果浓度降低到当前水平的第 5 个百分位数，铵可能会导致哮喘病例数显著减少（减少 1382 例，相当于总病例数的 22.37%）。
我们的研究表明，PM 的某些化学成分（包括黑碳、有机碳、硫酸盐、铵和硝酸盐）可能是导致哮喘患病率升高的危险成分；其中，如果降低到一定水平，铵可能会导致相当一部分哮喘病例。
