Short-Term Respiratory Effects and Attributable Burden of Atmospheric Dust in Ica, Peru

Background: Atmospheric dust is an increasingly recognized risk factor for respiratory morbidity, particularly in arid regions, yet evidence from Latin America remains limited. The Department of Ica, on the hyper-arid coast of Peru, is subject to recurrent wind-driven dust events (“Paracas winds”) that may affect respiratory health. This study aimed to evaluate the association between atmospheric dust concentration and respiratory emergency department (ED) visits, and to estimate attributable burden across the provinces of Ica. Methods: We conducted province-specific ecological time-series analyses (January 2023–May 2026) using distributed lag non-linear models (DLNMs). Exposure was defined as daily surface dust mass concentration (MERRA-2 DUSMASS). Models were adjusted for long-term/seasonal trends, day of week, holidays, temperature, and relative humidity. Cumulative relative risks (RRs) were estimated at the 90th, 95th, and 97.5th exposure percentiles relative to the province-specific median, and attributable fractions (AFs) were estimated. Results: Across 1247 days per province (94,559 respiratory ED visits overall), the most consistent positive exposure–response association was observed in Ica (97.5th-percentile RR, 1.47; 95% CI, 1.23–1.75). Chincha showed a positive association in the main model (RR, 1.39; 95% CI, 1.07–1.79), although these estimates were less robust in sensitivity analyses. Pisco showed an elevated but imprecise estimate at the 97.5th percentile (RR, 1.42; 95% CI, 1.01–1.99), whereas estimates for Nazca and Palpa did not provide consistent evidence of an association. AFs for dust above the median were 6.64% in Ica and 6.32% in Chincha, where attributable burden was distributed across moderate and high exposure intervals rather than concentrated at extremes. Conclusions: Province-specific estimates of the association between modeled atmospheric dust and respiratory ED visits varied in precision and robustness, with consistent evidence in Ica and greater uncertainty in the remaining provinces. Ground-based particulate monitoring would help improve exposure assessment and inform future dust surveillance in this region.