Pollen Counts and Allergic Disease in Wake County, North Carolina

BACKGROUND:  Climate change is predicted to have impacts on pollen production and allergic disease. To date, the relationship between pollen production and asthma outcomes has been established, however further research is necessary to fully understand the relationship between pollen production and other types of allergic disease.  In order to develop appropriate responses and fill this research need, pollen production and emergency department visits for allergic disease outcomes were studied in Wake County, North Carolina. 

METHODS:  Utilizing the Council for State and Territorial Epidemiologists State Environmental Health Indicator Collaborative, the suggested ICD-9-CM codes for allergic disease data for Wake County, North Carolina were analyzed, using the North Carolina Disease Event Tracking and Epidemiologic Collection Tool. Pollen counts from February to November for the years 2006 to 2011 for tree, weeds, and grasses were collected from a monitor maintained by North Carolina Department of Environment and Natural Resources.

RESULTS:  Pollen counts and allergic disease emergency department visits were analyzed using summary statistics and logistic regression. Trees consistently gave the highest pollen measurements, and tree pollen peaked in March. Weed pollen was highest in September, and grass pollen was highest in May. During 2006 through 2011, emergency department allergic disease visits in Wake County ranged between 2500 to 3500 visits annually.

CONCLUSIONS:  The Council of State and Territorial Epidemiologists State Environmental Health Indicator Collaborative (CSTE SEHIC) spurred North Carolina’s interest in studying the health effects from pollen. Understanding the impact of grass, weed, and tree pollen production on allergic disease outcomes is the first step of the Centers for Disease Control and Prevention’s Building Resilience Against Climate Effects framework. Further research will allow for projections and interventions that will aim to reduce morbidity from allergic disease in North Carolina.