The effect and burden of sand-dust storms on asthma hospitalization: Evidence from cities with arid climate in China

Evidence concerning the impact of sand-dust storms (SDS) on asthma is limited, and little is known about the associated public health burden, especially in regions with arid climate. Therefore, this study seeks to evaluate the effect of SDS on asthma hospitalization and quantify the associated hospital and economic burden in multiple cities with typical arid climate. We collected provincial asthma hospitalization, air pollutants and meteorological data of 14 cities in Gansu province. The space-time-stratified case-crossover design combined with a conditional quasi-Poisson regression was used to estimate the association between SDS and asthma hospitalization during 2018-2022. We further explored the interactive effect of SDS and low temperature, and explored potential effect modifications of gender, age, seasons and regions by stratified analyses. Finally, we calculated the hospital and economic burden of asthma attributed to SDS. A total of 54,134 hospitalization records for asthma and 791 SDS events were recorded during the study period. Northwestern area with arid climate displayed more frequent SDS events and asthma hospitalization compared with regions with subtropical or temperate monsoon climate. The relative risk (RR) of asthma hospitalization increased with SDS, with the greatest RR at lag1, which was 1.164 with a 95% confidence interval (CI) of 1.101-1.231. We further found that low temperature had an interactive effect with SDS to trigger asthma hospitalization. Stronger associations were observed in males, school-aged children, cold season and northwestern area. The total fraction of asthma hospitalization attributable to SDS was 1.64 % (95% CI: 1.06%-2.18%), and a conservative estimate of relative healthcare costs was 4.49 (95% CI: 2.92 to 5.99) million China Yuan. Our findings suggest the necessity of controlling SDS and implementing region-specific public health policies as well as personal protective measures against SDS.