Meng Shuyan, Qi Ling, Wu Pengpeng, Cao Suzhen, Zhang Kai, Wang Zongshuang, Duan Xiaoli
School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.
Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Rensselaer, NY, USA.
J Expo Sci Environ Epidemiol. 2025 Jun 17. doi: 10.1038/s41370-025-00775-1.
Traffic-related air pollution (TRAP) poses significant risks to human health, particularly in urban areas with high traffic volumes. Intake fraction (iF) quantifies the relationship between emissions and exposure, defined as the ratio of the total inhalation increment of all exposed individuals in a target population to the emissions from specific pollution sources over a certain period.
The overarching objective of this study is to unravel the underlying value and significance of the iF method in evaluating TRAP exposure risks, while also exploring its future development trajectories and potential avenues for application.
We conducted a comprehensive review of iF to assess TRAP exposure. We employed a search strategy to identify and analyze literature on iF methods related to TRAP exposure across academic databases covering the period from 2002 to 2024. After deduplication, title and abstract screening, and full-text review, we ultimately included 25 studies on iF related to TRAP.
We classified the measurement methods of iF into four types: simple estimation method, dispersion simulation method, numerical simulation method, and exposure monitoring method. We found orders of magnitude of differences in iF among studies. Population density, pollutant concentration, and breathing rate explain a significant portion of the variations. iF values of nitrogen oxides (NO), carbon monoxide (CO), and fine particulate matter (PM) are higher than those of diesel particulate matter (DPM), ultrafine particles (UFP), and benzene. Compared to power plants, TRAP has higher iF values, emphasizing the control priority of TRAP. Future research should expand to under-researched regions, strengthen investigations on UFP and secondary pollutants, and refine iF calculation methods using high-resolution and mobility data.
交通相关空气污染（TRAP）对人类健康构成重大风险，在交通流量大的城市地区尤为如此。摄入分数（iF）量化了排放与暴露之间的关系，定义为目标人群中所有暴露个体的总吸入增量与特定污染源在一定时期内的排放之比。
本研究的总体目标是揭示iF方法在评估TRAP暴露风险中的潜在价值和意义，同时探索其未来的发展轨迹和潜在应用途径。
我们对iF进行了全面综述，以评估TRAP暴露。我们采用搜索策略，在涵盖2002年至2024年期间的学术数据库中识别和分析与TRAP暴露相关的iF方法的文献。经过去重、标题和摘要筛选以及全文审查，我们最终纳入了25项与TRAP相关的iF研究。
我们将iF的测量方法分为四种类型：简单估计法、扩散模拟法、数值模拟法和暴露监测法。我们发现不同研究之间iF存在数量级差异。人口密度、污染物浓度和呼吸速率解释了很大一部分变化。氮氧化物（NO）、一氧化碳（CO）和细颗粒物（PM）的iF值高于柴油颗粒物（DPM）、超细颗粒物（UFP）和苯。与发电厂相比，TRAP的iF值更高，这突出了TRAP的控制优先级。未来的研究应扩展到研究较少的地区，加强对UFP和二次污染物的调查，并使用高分辨率和流动性数据完善iF计算方法。
