ICAM1 and inflammation: Next, we investigated the role of ROS in PMs-induced pulmonary inflammation, pre-administration of NAC (3–5 mg/mouse) before intratracheal instillation of PMs (200–350 μg/mouse, 7 days) significantly attenuated PMs-induced ICAM-1 and IL-6 expression in lung tissues by immunohistochemical staining (Fig. 6f).