Li Kuan, Bao Yijing, Gao Jing, Chen Bilan, Xia Yang, Zhao Yuhong, Chen Huaiyong, Wang Jianhai, Zhang Hehua
Tianjin Key Laboratory of Lung Regenerative Medicine, Haihe Hospital, Tianjin University, Tianjin, 300350, China.
Tianjin Institute of Respiratory Diseases, Tianjin, 300350, China.
Eur J Pediatr. 2025 Jun 6;184(7):395. doi: 10.1007/s00431-025-06214-5.
Over the past decades, a growing body of research has explored the associations between various chemical constituents of fine particulate matter (PM) and childhood asthma. However, findings have been largely inconsistent. This study aims to synthesize evidence on the impact of short- and long-term exposure to PM chemical constituents on asthma risk and lung function changes in children and adolescents. The study protocol has been registered on PROSPERO (CRD 42024562521). We systematically searched for articles on the associations between the black carbon (BC), organic carbon (OC), ammonium (NH), nitrate (NO), sulfate (SO), and heavy metals in PM and the risk of asthma and lung function (forced vital capacity [FVC], forced expiratory volume in one second [FEV1], etc.) published up to January 2025, throughout databases of the Web of Science, MEDLINE, PubMed, and EMBASE. The overall effect size (OR: odds ratio; or SMD: standard mean difference) with a 95% confidence interval (CI) was calculated using a random-effect model. Heterogeneity among the research findings was assessed using the I-squared (I) statistic. A total of 24 original studies with a sample size of 6,978,265 were included. Twelve studies focused on long- and 12 on short-term associations. The inter-quartile range (IQR) values for BC, OC, SO, NO, and NH in PM were 0.61, 1.68, 4.23, 3.48, and 1.38 μg/m, respectively. For the long-term association, every IQR increase of OC, NH, and BC was associated with 37% (pooled OR = 1.370), 28.5% (pooled OR = 1.285), and 7.4% (pooled OR = 1.074) higher risk of childhood asthma; every IQR increase of BC and SO was associated with reduced FEV1 (SMD: 0.068 L and 0.639 L) and FVC (SMD: 0.144 L and 0.479 L). Every IQR increase of BC exposure was associated with reduced FEV1 (SMD: 0.061 L) and PEF (SMD: 0.130 L). Short-term exposure to SO, NH, NO, BC, Fe, and Zn was also associated with higher asthma admissions with no significant heterogeneity.
Long-term and short-term exposures to BC, OC, and NH are the main contributing chemical constituents in PM for childhood asthma. BC and SO are the main contributors for reduced lung function in children and adolescents.
• PM2.5 impacts respiratory health, but which specific component most harms asthma and lung function of children remains unclear.
• This systematic review and meta-analysis found that black and organic carbon, as well as ammonium, mainly contributed to increased asthma risk, while black carbon and sulfate in PM2.5 were key factors for reduced lung function in children.
在过去几十年中，越来越多的研究探讨了细颗粒物（PM）的各种化学成分与儿童哮喘之间的关联。然而，研究结果在很大程度上并不一致。本研究旨在综合证据，以了解短期和长期接触PM化学成分对儿童和青少年哮喘风险及肺功能变化的影响。该研究方案已在国际前瞻性系统评价注册库（PROSPERO）上注册（注册号：CRD 42024562521）。我们系统检索了截至2025年1月发表的关于PM中的黑碳（BC）、有机碳（OC）、铵（NH）、硝酸盐（NO）、硫酸盐（SO）和重金属与哮喘风险及肺功能（用力肺活量[FVC]、一秒用力呼气容积[FEV1]等）之间关联的文章，检索范围涵盖科学引文索引（Web of Science）、医学索引数据库（MEDLINE）、美国国立医学图书馆生物医学文献数据库（PubMed）和荷兰医学文摘数据库（EMBASE）。使用随机效应模型计算总体效应量（OR：比值比；或SMD：标准化均数差）及95%置信区间（CI）。采用I²统计量评估研究结果之间的异质性。共纳入24项原始研究，样本量达6978265。其中12项研究关注长期关联，12项关注短期关联。PM中BC、OC、SO、NO和NH的四分位距（IQR）值分别为0.61、1.68、4.23、3.48和1.38μg/m³。对于长期关联，OC、NH和BC每增加一个IQR，儿童哮喘风险分别升高37%（合并OR = 1.370）、28.5%（合并OR = 1.285）和7.4%（合并OR = 1.07）；BC和SO每增加一个IQR，FEV1（SMD分别为0.068 L和0.639 L）和FVC（SMD分别为0.144 L和0.479 L）降低。BC暴露每增加一个IQR，FEV1（SMD为0.061 L）和呼气峰值流速（PEF，SMD为0.130 L）降低。短期暴露于SO、NH、NO、BC、铁和锌也与更高的哮喘入院率相关，且无显著异质性。
长期和短期暴露于BC、OC和NH是PM中导致儿童哮喘的主要化学成分。BC和SO是导致儿童和青少年肺功能降低的主要因素。
• PM2.5影响呼吸健康，但哪种特定成分对儿童哮喘和肺功能危害最大尚不清楚。
• 本系统评价和荟萃分析发现，黑碳和有机碳以及铵主要导致哮喘风险增加，而PM2.5中的黑碳和硫酸盐是儿童肺功能降低的关键因素。
