## 4 Conclusions  
In conclusion, the air mass of AD from Northwest and Central China strongly influenced TSP, but did not consistently affect PAH concentrations in Fukuoka and Kanazawa. Backward trajectories showed that the AD originated from Northwest and Central China or Mongolia deserts for a long distance (more than 6000 km) at a planetary weather scale with transporting heights of 1000-6000 m. In comparison, the LRT-PAHs came from industrial and city areas near/on the east coast of China with a short distance (800-2000 km) on a synoptic weather scale (transporting height: 500-4000 m). The LRT-PAH from above 35\({}^{\circ}\) N latitude areas (Manchurian industrial area and Bohai Economic Rim) impacted Fukuoka and Kanazawa. In contrast, LRT-PAH from below 35\({}^{\circ}\) N latitude areas (Yangtze River Delta) affected mainly Fukuoka. In addition, local emissions presented different effects from city to city in Japan. The major PAH source is traffic in Kanazawa, while it is the mixed source of industrial and traffic emissions in Fukuoka.  
This is the first report to clarify the daily and seasonal effects of TSP and PAHs on long-distant sites in Japan during the AD period, which is important for studying chronic and acute respiratory disease mechanisms. The following study will analyze NPAHs in the same air samples and estimate source contributions of TSP, PAHs, and NPAHs in Fukuoka and Kanazawa by the NP-method, which uses 1-nitrophenyl and Pyr as markers [2; 21; 26].  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app12115404/s1](https://www.mdpi.com/article/10.3390/app12115404/s1)]([https://www.mdpi.com/article/10.3390/app12115404/s1](https://www.mdpi.com/article/10.3390/app12115404/s1)), Figure S1: High-volume air samplers at Fukuoka and Kanazawa; Figure S2: Illustration of possible LRT-PAH sources and routes from China to Japan from March to May; Table S1: Dates of AD events and their TSP and PAH concentrations in Fukuoka and Kanazawa in 2020 and 2021.  
Conceptualization, K.-O.P. and K.H.; methodology, K.-O.P., J.Z., K.H. and H.N.; software, K.S.; validation, K.H.; formal analysis, K.-O.P.; investigation, K.-O.P.; resources, H.M., H.O., A.H., H.N. and A.M.; data curation, A.H. and H.N.; writing--original draft preparation, K.-O.P.; writing-- revising and editing, K.-O.P., K.S., A.M., Y.L and K.H.; visualization, K.-O.P. and K.H.; supervision, H.N. and K.H.; project administration, H.N.; funding acquisition, H.N. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Environment Research and Technology Development Fund (JPMEERF20195051) of the Environmental Restoration and Conservation Agency of Japan.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy.  
The authors are grateful to [PERSON] at NIES for providing LIDAR data.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.