Changes in Timing of Spring Onset, Pollen Exposure, and Burden of Allergic Disease in the Northeastern United States

Abstract

BACKGROUND AND AIM: Ongoing climate variability and change is altering the timing of spring onset, a critical event that signifies the start of tree pollen season in North America. There is a paucity of data regarding how such changes in the timing of spring onset impact burden of allergic disease in the Northeast United States. METHODS: We processed Landsat and MODIS observations for New York and Maryland during 2001-2015 to derive the start of spring (SOS) using double logistic model and aggregated them to county level. We then calculated yearly deviations in SOS for each county for MD and NY from their respective long term median values (2001-2015). These deviations were categorized as very early, early, normal, late and very late. We linked these yearly deviations in SOS with asthma hospitalization for MD and NY during 2001-2015, based on the county of residence. We used general additive (quasi Poisson) and mixed-effect (negative binomial) models to investigate the association between changes in the timing of spring onset and asthma hospitalization. RESULTS:Very early onset of spring was associated with a 17% increase in asthma hospitalization in Maryland during spring season (incident rate ratio [IRR], 1.17; 95% CI, 1.07-1.28). Likewise late onset of spring was associated with a 7% increase in asthma hospitalization (IRR, 1.07; 95% CI, 1.00-1.15). Adjustments for extreme heat event and particulate matter with aerodynamic diameter less than 2.5 microns (PM2.5) did not change result for very early onset of spring, but late onset was no longer statistically significant. Similar analysis for NY is ongoing and will be covered in the presentation. CONCLUSIONS:Our findings suggest that early onset of spring that are tied to warming climate may increase burden of allergic disease such as asthma. KEYWORDS: Climate Change, phenology, asthma, pollen, allergy