Long-term exposure to dust in fine particulate matter and post-stroke functional impairment-Findings from the China National Stroke Screening Surveys.

The dust component of particulate matter (PM) warrants more attention in the era of climate change and increased frequency of dust event, yet rarely are studies focused exclusively on the long-term health effects of dust PM2.5. This study aims to assess the relative toxicity of dust and non-dust PM2.5 on the long-term functional impairment after stroke. We utilized data from a multicenter, national survey in China from 2013 to 2019 and selected participants with repeated assessments of the functional impairment outcomes, the modified Rankin scale (mRS) score, to form a longitudinal dataset. The dust PM2.5 exposure data were constructed by combining multiple sources and of high spatial resolution. Fixed effect models were used to estimate the association between dust PM2.5 exposure and changes in mRS scores. A two-dimensional spline model was used to model the joint effect of dust and non-dust PM2.5 exposure. We included 28,081 participants (65,883 visits). Per interquartile range increase of the dust PM2.5 was associated with 0.048 (95 % confidence interval [CI]: 0.003-0.092) increase in mRS score. Results of co-exposure to dust and non-dust PM2.5 showed that the greater the proportion of dust PM2.5 was, the stronger the combined effect. This study revealed that long-term exposure to dust PM2.5 was associated with post-stroke functional impairment. More studies on the long-term effects of dust and dust-sourced PM2.5 on neurological outcomes are warranted in the future.