Inhalation risks depend on the size distribution of ambient particulate matter (PM) bound toxicants, which are influenced by various sources. This study explored variations in source-specific risks across different respiratory tract regions and their association with size-resolved toxicants. Potentially toxic elements contribute significantly, accounting for over 93% of the inhalation risk, followed by polycyclic aromatic hydrocarbons at 0.3%–7%, and organophosphate esters at less than 0.01%. For adults, the contribution of non-cancer and cancer risks within respiratory tracts was as follows: upper respiratory tract (∼61%) > pulmonary (∼30%) region > tracheobronchial (∼8%) region. Differently, for children, the order was pulmonary (∼43%) > upper respiratory tract (∼41%) > tracheobronchial (∼17%). In the adult population, resuspended dust (RD) presented elevated non-cancer risks in the upper respiratory tract compared to the tracheobronchial and pulmonary regions, while coal combustion (CC), traffic emission (TE), and waste recycling or incineration (WI) contribute most to pulmonary risks. In contrast, for children, non-cancer risk associated with CC surpassed RD in the upper respiratory tract, whereas RD exceeded CC in the tracheobronchial region. This discrepancy arises because RD primarily consists of coarse PM with higher deposition fractions in the adults' upper respiratory tract and children's tracheobronchial region, while toxicants from CC, TE and WI, with PM < 0.43 μm, are inclined to have a greater impact on the pulmonary region. Regarding source cancer risks, RD exhibited a consistent decrease across all three respiratory tract regions, with primary dominance observed in industrial emissions (IE), CC, and TE sources.

中文翻译：

---

尺寸分辨 PM 结合多种毒物的源特异性风险评估：呼吸道中源特异性风险的变化

吸入风险取决于环境颗粒物 (PM) 结合毒物的大小分布，而这些毒物受到各种来源的影响。这项研究探讨了不同呼吸道区域的特定来源风险的差异及其与尺寸分辨毒物的关联。潜在有毒元素贡献显着，占吸入风险的 93% 以上，其次是多环芳烃，占 0.3%–7%，有机磷酸酯占不到 0.01%。对于成年人来说，呼吸道内非癌症和癌症风险的贡献如下：上呼吸道（∼61%）>肺部（∼30%）区域>气管支气管（∼8%）区域。不同的是，对于儿童来说，顺序是肺部（~43%）>上呼吸道（~41%）>气管支气管（~17%）。在成年人群中，与气管支气管和肺部区域相比，重悬浮粉尘（RD）在上呼吸道的非癌症风险更高，而煤炭燃烧（CC）、交通排放（TE）和废物回收或焚烧（WI）肺部风险的贡献最大。相比之下，对于儿童来说，上呼吸道中与 CC 相关的非癌症风险超过了 RD，而气管支气管区域中的 RD 超过了 CC。出现这种差异的原因是，RD 主要由粗颗粒 PM 组成，在成人上呼吸道和儿童气管支气管区域沉积分数较高，而来自 CC、TE 和 WI 的有毒物质，PM < 0.43 μm，对颗粒物的影响往往更大。肺部区域。关于来源癌症风险，RD 在所有三个呼吸道区域均表现出持续下降，其中工业排放 (IE)、CC 和 TE 来源占主导地位。