Fig. 3.
Hazard ratios of (A) dementia or (B) Alzheimer’s disease (AD) associated with per IQR or per 1 µg/m3 increase in annual mean concentration of each PM2.5 major constituent, respectively, including BC, OM, soil dust (DUST), NO3−, SO42−, and NH4+. The dotted lines stand for the corresponding results for PM2.5 mass. The estimated hazard ratios were obtained from single-constituent models, and error bars stand for the 95% CIs. The light and dark colors are used to distinguish air pollutants derived from two exposure models, with the light one indicating exposure I data (11) and the dark one indicating exposure II data (12). The corresponding hazard ratio values could be found in SI Appendix, Tables S3 and S4 (Model 1).