Levels of airborne allergenic pollen species in Charleston, South Carolina, from 2017 to 2021, in relation to climate change, air pollutants, and asthma-related emergency department visits.

Background: Currently, around 44.2 million Americans have been diagnosed with asthma, which ranks as the
third leading cause of pediatric hospitalizations. This condition disproportionately affects females compared to males. Furthermore, the annual healthcare costs linked to the rising number of asthma-related emergency
department (ED) visits exceed $80 billion. Global warming and climate change can lead to extreme weather
events, potentially affecting various asthma triggers, including specific types of airborne pollen, ozone, sulfur
dioxide (SO2), and nitrogen dioxide (NO2). However, the relationship between these factors and asthma-related
ED visits in coastal areas remains inadequately understood.
Methodology: Asthma ED visits for Charleston and data on seven different airborne pollen species, ozone,
SO2, and NO2 for the primary allergy seasons (March – September) were obtained from the National Allergy
Bureau of the American Academy of Allergy Asthma and Immunology (AAAAI) and other federal and state
agencies.
Results: Spearman correlation results showed significant positive correlations between asthma-related monthly
ED visits and pollen species such as Juniper (p=0.0152), Grass (Gramineae or Poaceae) (p=0.0164),
Liquidambar (Hamamelidaceae) (p=0.0014), Acer (Aceraceae) (p=0.0134), Betula (Betulaceae) (p=<0.0001),
Pinaceae (p=0.0342), Quercus (Fagaceae) (p=0.1034). There were negative correlations between all selected
seven pollen species and the average temperature (p=<0.0001), and relative humidity (p=<0.0001). Monthly
average asthma-related ED visits were negatively correlated with the average temperature (p=0.0146), and
relative humidity (p=0.0434). All pollen species were significantly positively correlated with ozone levels and not
significantly associated with SO2 levels except for Betula