Background: Ultrafine particles (UFP) emerged as a particularly concerning air pollutant due to their potential adverse health effects, especially on neurodegenerative diseases. However, the health effects of UFPs are not yet fully understood, partly due to limited monitoring and studies. This study aims to explore the association between long-term UFP exposure and neurodegenerative disorders mortality, considering social demographic disparities, seasonal patterns, and the modifying effects of meteorological factors and other critical air pollutants (i.e., O3, NH3, SO2, summer temperature, winter temperature, and relative humidity).

Methods: We used a Difference-in-Difference design at the county subdivision level in New York State (NYS) from 2013 to 2019, with exposure data on UFPs, other pollutants, and meteorological factors simulated using GEOS-Chem-APM at 17*17 miles refined resolution. Mortality data on neurological disorders was obtained from Vital Records for Upstate NY and NYC.

Results: Neurodegenerative disorder-related mortality and its subtypes (i.e., Alzheimer, Dementia, and Parkinson) generally increased over the period from 2013 to 2019 in NYS, with a significant association between UFP exposure and excess risk of neurodegenerative disease-related mortality (ERIQR=6.49), particularly Alzheimer's (ERIQR=20.93). Females, Hispanics, non-Hispanic whites, older adults (>=65 yrd), and individuals living in urban or suburban areas showed a significant excess risk from UFP exposure (ERIQR ranged from 8.27 to 49.21). The UFP-mortality association was significant during winter (ERIQR=8.74), but not in other seasons. The modification effects of meteorological factors and other air pollutants on UFP- mortality associations were not statistically significant.

Conclusions: These findings indicate a long-term association between UFP exposure and Neurodegenerative disorder-related mortality, particularly Alzheimer's, with higher risks observed among specific demographic groups. However, Meteorological factors or other air pollutants did not modify the associations.

¹ Institute for Health and the Environment, University at Albany, State University of New York, Rensselaer, NY

² Department of Economics, University at Albany, State University of New York, Albany, NY

³ New York State Department of Health, Albany, NY

⁴ Department of Educational Psychology, University at Albany, State University of New York, Rensselaer, NY

⁵ Atmosphere Science Research Center, University at Albany, State University of New York, Albany, NY

*Corresponding Author: rtangang@albany.edu