Hourly Exposure to Ambient Air Pollutants and Risk of Acute Aortic Dissection: Evidence From 162 Chinese Cities.

Abstract

To examine the association between hourly spikes in air pollutant exposure and the risk of acute aortic dissection (AAD) onset. This time-stratified case-crossover study analyzed a national Chinese registry of 3125 AAD cases across 162 cities. Piecewise conditional logistic regression and distributed lag nonlinear models were used to estimate relative risks (RRs) and 95% confidence intervals. Increases in PM 10 (RR = 1.019 per 10 μg/m 3 ) and CO (RR = 1.184 per 1 mg/m 3 ) were associated with higher AAD risk. Exposure above thresholds yielded increased risks for PM 2.5 > 200 μg/m 3 (RR = 1.074 per 10 μg/m 3 ) and NO 2 > 100 μg/m 3 (RR = 1.065 per μg/m 3 ). Effects showed lagged patterns for CO and PM 10 . Males, older adults, hypertensive patients, smokers, and overweight individuals showed greater susceptibility. This study provides the first evidence that hourly air pollution spikes significantly increase AAD risk, supporting targeted public health measures.