Trends in seasonal pollen and asthma-related morbidity among adults and children in a U.S. high-density urban center, 2001-2020

Abstract

Objective

To analyze the long-term trends in pollen counts and asthma-related emergency department visits (AREDV) in adult and pediatric populations in the Bronx.

Methods

Daily values of adult and pediatric AREDV were retrospectively obtained from three major Bronx hospitals using ICD-10 codes and pollen counts were obtained from the Armonk station from 2001–2020. Wilcoxon Ranked Sum was applied to compare median values, while Spearman correlation was employed to examine the association between these variables, for both decades and each season.

Results

The median value of pediatric AREDV increased by 200% from the 1st to 2nd decade (p < 0.001) and AREDV peak shifted from predominantly the spring season in the 1st decade to the fall and winter seasons in the 2nd decade. Seasonal patterns were consistent over 20 years with summer AREDV lower than all other seasons (9 vs. 17 per day) (p < 0.001). Spring tree pollen peaks were correlated with AREDV peaks (rho = 0.34) (p < 0.001). Tree pollen exceeding 100 grains/m³ corresponded to a median of 19.0 AREDVs while all other tree pollen (0 − 99 grains/m³) corresponded to a median of 15.0 AREDVs (p < 0.001). AREDVs sharply declined in 2020, coinciding with the emergence of COVID-19.

Conclusions

Pollen and AREDVs peak earlier in the spring and are more strongly interconnected, while asthma rates among children are rapidly rising, particularly in the fall and winter. These findings can advise targeted awareness campaigns for better management of asthma related morbidity.

Keywords:

• Asthma
• emergency department visits
• surveillance
• pollen
• epidemiology
• urban

Acknowledgements

We thank Dr. Guy Robinson and Dr. Kate Weinberger, Louis Calder Center, Fordham University for providing and organizing pollen data in the Bronx, NY, from 2001–2020.

Author contributions

Dr. Sunit Jariwala conceived of the study and, along with Kyle Mani and Raphael Miller, participated in study design. Dr. Sunit Jariwala provided patient databases, and Kyle Mani and Dr. Juan Lin performed statistical analysis. Kyle Mani and Jai Shahani organized pollen count data from the Armonk Station, while Dr. Sunit Jariwala provided the abstracted asthma data from the electronic medical records. Kyle Mani, Raphael Miller, and Dr. Sunit Jariwala all drafted the manuscript. All authors read and approved the final manuscript.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Funding source

None.