In this study, PAHs and their transformed PAH products (TPPs) in road dust were subjected to UV driven photolysis, and then quantified using simultaneous pressurized fluid extraction, and analysed using Shimadzu Triple Quadrupole GC/MS. The results of the analysis were used to investigate the robustness and reliability of 14 existing diagnostic ratios (DRs) and two newly proposed molecular DRs that are relevant for characterizing the sources of PAHs and TPPs. The influence of photolysis on the carcinogenic health risk posed to humans by these hazardous pollutants was then assessed. The findings indicated that the DRs segregated into stable, moderately stable and non-stable classes of source characteristics under the influence of photolysis. Only two of the existing DRs, namely, benzo(a)pyrene/benzo(ghi)perylene (BaP/BghiP) and total index exhibited consistent stability to photolysis, whilst fluoranthene/(fluoranthene + pyrene) (FRT/(FRT+PYR)) showed moderate stability. The two newly proposed DRs, naphthalene/1-nitronaphthalene (NAP/NNAP) and pyrene/(1-nitropyrene + 1-hydroxypyrene) (PYR/(1NPY+HPY)) were found to be highly reliable in post-emission source characterization. The cross-plots of the most stable DRs showed that traffic emissions is the primary source of PAHs, whilst post-emission photolysis is the secondary source of nitro-PAH (NPAH) TPPs. The percent resonance energy thermodynamic stability of the PAH pollutants does not exert any direct influence on the source characteristics of the DRs. Adults are more vulnerable to potential carcinogenic risks as a result of PAH and TPPs photolysis whereas negligible risk exist for children. This study contributes to a more reliable diagnosis of PAH and TPP sources and thus, to the regulatory mitigation of these hazardous pollutants thereby, promoting enhanced protection of human health and the environment.

在这项研究中，将道路灰尘中的PAH及其转化的PAH产物（TPP）进行UV驱动的光解，然后使用同时加压流体萃取进行定量，并使用Shimadzu Triple Quadrupole GC / MS进行分析。分析的结果用于调查14种现有诊断率（DR）和两个新提出的分子DR的稳健性和可靠性，这两个特征与表征PAHs和TPPs的来源有关。然后评估了光解对这些有害污染物对人类构成致癌健康风险的影响。研究结果表明，在光解作用下，DR分为源特性的稳定，中度稳定和不稳定类别。现有DR中只有两个，即 苯并（a）//苯并（ghi）ylene（BaP / BghiP）和总指数对光解表现出稳定的稳定性，而荧蒽/（荧蒽+））（FRT /（FRT + PYR））显示出中等的稳定性。发现两个新提出的DR，萘/ 1-硝基萘（NAP / NNAP）和pyr /（1-硝基py + 1-羟基py）（PYR /（1NPY + HPY））在排放源表征中高度可靠。最稳定的DR的交叉图显示，交通排放是PAHs的主要来源，而排放后的光解则是硝基PAH（NPAH）TPP的次要来源。PAH污染物的共振能百分率热力学稳定性不会直接影响DR的源特性。由于PAH和TPPs的光解作用，成年人更容易受到潜在的致癌危险，而儿童的危险则可以忽略不计。这项研究有助于更可靠地诊断PAH和TPP来源，从而有助于减轻这些有害污染物的管制，从而促进对人类健康和环境的保护。