“…These filters were mounted on different volume air samplers as needed. Because the concentrations of NPAHs are very low in the atmosphere, a high‐volume air sampler (300–1000 L/min) is used for collecting airborne particulates such as PM 2.5 (Albinet, Leoz‐Garziandia, Budzinski, & Villenave, ; Hayakawa, ; Tang et al, ). Several higher‐level NPAHs (2‐nitrofluorene, 9‐nitroanthracene, 9‐nitrophenanthrene, 3‐nitrofluoranthene, 1‐nitropyrene, 2,7‐dinitrofluorene, 7‐nitrobenz[ a ]anthracene and 6‐nitrochrysene) in the atmosphere could be collected by using a low‐volume air sampler (38 L/min, 24 h) (Tutino, Di Gilio, Laricchiuta, Assennato, & de Gennaro, ).…”