To evaluate AD-related neuronal toxicity, different expression levels of certain AD-related hallmarks, such as Aβ42, t-tau, and p-tau, and the autophagosome marker (LC3B) and neuroinflammation marker (Iba-1) in the cortex, hippocampus, olfactory bulb, and cerebellum of mice in the PM2.5-exposed (n = 6) and control groups (n = 7) after 3 months of exposure are shown in Fig 5. Here, MAPT is linked to Alzheimer disease.