IMPORTANCE: Dust storms are projected to increase with climate change. The short-term health outcomes associated with dust storms in the US are not well characterized, especially for morbidity outcomes. OBJECTIVE: To estimate associations between dust storms and diagnosis-specific emergency department (ED) visits during 2005 to 2018. DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional study using a time-stratified case-crossover design, short-term associations between dust storms and ED visits were estimated at the zip code level using conditional Poisson analysis with adjustment for meteorology and within-month trends. Same-day dust storm events and storm events within a lag period of up to 7 days were considered. State-wide patient-level ED visit records acquired from 3 state health departments (Arizona, California, and Utah) were analyzed. Data were analyzed between April 21 and November 12, 2024. EXPOSURES: Dust storm events were reported by the US National Weather Service and assigned to each patient zip code that had at least a 5% areal overlap with the National Weather Service forecast zone. MAIN OUTCOMES AND MEASURES: Patient-level ED visits for asthma, chronic obstructive pulmonary disease, culture-negative pneumonia, congestive heart failure (CHF), cerebrovascular disease, ischemic heart disease, and visits due to motor vehicle accidents. RESULTS: The analysis included 33 500 ED visits among the outcomes of interest (5717 children aged 0-17 years [17.1%] and 11 150 adults aged >
65 years [33.3%]
17 394 male [51.9%] and 16 104 female [48.1%]
2829 Black [8.4%] and 22 537 White [67.2%]
9256 Hispanic [27.6%]) and 206 dust-impacted zip codes. The strongest associations between dust storms and ED visits were found for asthma (lag 0-2 relative risk [RR], 1.06
95% CI, 1.01-1.11
P = .03), culture-negative pneumonia (lag 0-7 RR, 1.06
95% CI, 1.02-1.10
P = .002), CHF (lag 0-7 RR, 1.06
95% CI, 1.01-1.10
P = .01), and motor vehicle accidents (lag 0 RR, 1.13
95% CI, 1.04-1.23
P = .003). Associations of dust storm exposure with ischemic heart disease were mostly protective (eg, lag 0-2 RR, 0.89
95% CI, 0.84-0.95
P <
.001). Associations of dust storm exposure with risk of ED visits for CHF and motor vehicle accidents were robust against adjustment for ambient ozone (eg, CHF: RR, 1.08
95% CI, 1.03-1.13
P = .003) and nitrogen dioxide (eg, CHF: RR, 1.08
95% CI, 1.03-1.13
P = .003) air pollution. CONCLUSIONS AND RELEVANCE: In this study, dust storms were positively associated with ED visits for asthma, pneumonia, heart failure, and motor vehicle accidents. These findings contribute to our understanding of the association of dust storms with morbidity in the US and potential outcomes under a changing climate.