The respiratory tract deposited fraction (DF) is the link between exposure and health effects of airborne particles. Here, we investigate how breathing pattern alterations at increasing physical activity affect DF in different regions of the respiratory tract and compare DF between adults and children (5 and 10 years old). We performed a literature review on the alteration of tidal volume with minute ventilation at increasing physical activity and used the results to model the size resolved (0.001–10 µm) DF, primarily using the deposition models from NCRP and Yeh and Schum (1980), but also MPPD. We found a shift in the deposited size distribution with increasing physical activity—DF of ultrafine particles increased in the alveolar region and decreased in the other regions, while DF of coarser particles decreased in the alveolar region and increased in the extra-thoracic region. Children had a 10–20% higher DF of ultrafine particles in the alveolar region compared to adults. We also present parametrizations of the daily average size resolved (0.005–5 µm) DF, accounting for varying physical activity throughout the day and oral/nasal breathing. These can be applied to any size distribution to estimate deposited doses. We found that deposited mass and number doses were more than twice as high for 5-year-olds compared to adults when normalized for body weight, primarily caused by their higher weight normalized minute ventilation. This demonstrates the importance of studying children’s exposure to air pollution and not only rely on data from adults.

呼吸道沉积分数 (DF) 是空气颗粒物暴露与健康影响之间的联系。在这里，我们研究增加体力活动时呼吸模式的改变如何影响呼吸道不同区域的 DF，并比较成人和儿童（5 岁和 10 岁）之间的 DF。我们对增加体力活动时潮气量随每分钟通气量的变化进行了文献综述，并使用结果对尺寸分辨率 (0.001–10 µm) DF 进行建模，主要使用 NCRP 以及 Yeh 和 Schum (1980) 的沉积模型，还有MPPD。我们发现，随着体力活动的增加，沉积的粒径分布发生变化——超细颗粒的 DF 在肺泡区域增加，而在其他区域减少，而较粗颗粒的 DF 在肺泡区域减少，在胸外区域增加。与成人相比，儿童肺泡区域超细颗粒的 DF 高出 10-20%。我们还提出了每日平均尺寸解析（0.005-5 µm）DF 的参数化，考虑了全天不同的身体活动和口/鼻呼吸。这些可以应用于任何尺寸分布来估计沉积剂量。我们发现，当体重标准化时，5 岁儿童的沉积质量和数量剂量是成年人的两倍多，这主要是由于他们的体重标准化每分钟通气量较高。这表明研究儿童接触空气污染的情况的重要性，而不仅仅是依赖成人的数据。