Ambient pollen concentrations and emergency department visits for asthma and wheeze

doi:10.1016/j.jaci.2012.06.020

Journal of Allergy and Clinical Immunology

Volume 130, Issue 3, September 2012, Pages 630-638.e4

https://doi.org/10.1016/j.jaci.2012.06.020 Get rights and content

Background

Previous studies report associations between aeroallergen exposure and asthma exacerbations. Aeroallergen burdens and asthma prevalence are increasing worldwide and are projected to increase further with climate change, highlighting the importance of understanding population-level relationships between ambient pollen concentrations and asthma.

Objective

We sought to examine short-term associations between ambient concentrations of various pollen taxa and emergency department (ED) visits for asthma and wheeze in the Atlanta metropolitan area between 1993 and 2004.

Methods

We assessed associations between the 3-day moving average (lag 0-1-2) of Betulaceae (except Alnus species), Cupressaceae, Quercus species, Pinaceae (except Tsuga species), Poaceae, and Ambrosia species pollen concentrations and daily asthma and wheeze ED visit counts, controlling for covarying pollen taxa and ambient pollutant concentrations.

Results

We observed a 2% to 3% increase in asthma- and wheeze-related ED visits per SD increase in Quercus species and Poaceae pollen and a 10% to 15% increased risk on days with the highest concentrations (comparing the top 5% of days with the lowest 50% of days). An SD increase in Cupressaceae concentrations was associated with a 1% decrease in ED visits. The association for Quercus species pollen was strongest for children aged 5 to 17 years. Effects of Ambrosia species pollen on asthma exacerbations were difficult to assess in this large-scale temporal analysis because of possible confounding by the steep increase in circulating rhinoviruses every September.

Conclusion

Poaceae and Quercus species pollen contribute to asthma morbidity in Atlanta. Altered Quercus species and Poaceae pollen production caused by climate change could affect allergen-induced asthma morbidity in the southeastern United States.

Section snippets

Pollen data

Airborne pollen concentrations were measured by the Atlanta Allergy and Asthma Clinic, a member of the National Allergy Bureau, between January 1, 1993, and December 31, 2004 (Fig 1). The monitoring site was moved once on January 1, 2000; pollen was sampled from the same rooftop height at both locations and away from vegetation, air conditioners, and building vents. National Allergy Bureau–certified Atlanta Allergy and Asthma Clinic staff analyzed air samples 5 days per week (Sunday-Thursday)

Descriptive statistics

Over the 1993-2004 time period, there were 400,819 ED visits for asthma and wheeze (0-4 years = 108,147 visits; 5-17 years = 91,386 visits, and ≥18 years = 201,286 visits). ED visits are further described in Table E1 in this article's Online Repository at www.jacionline.org. Raw data plots shown in Fig E1 in this article's Online Repository at www.jacionline.org demonstrate recurrent seasonal patterns of ED visits. Ambient pollen concentrations were highly skewed, with concentrations that were

Discussion

Overall, these results suggest that ambient pollen, in particular Quercus species and Poaceae pollen, independently contribute to asthma morbidity in Atlanta. We observed a 2% to 3% increased risk of asthma-related ED visits per SD increase in pollen levels and a corresponding 10% to 15% increase in risk on days with the highest concentrations (comparing the top 5% of days with the lowest 50% of days) for Quercus species and Poaceae pollen. The magnitudes of association observed are similar to

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: Supported by the Centers for Disease Control and Prevention (TKC Global Solutions, LLC: JR5000139), the US Environmental Protection Agency (USEPA; RD834799), and the National Institute of Environmental Health Sciences (NIEHS; R03ES018963). Creation of the emergency department database was supported by the USEPA (RD833626), the NIEHS (R01ES11294), and the Electric Power Research Institute (EP-P277231/C13172). The content of this publication is solely the responsibility of the grantee and does not necessarily represent the official views of the USEPA. Furthermore, USEPA does not endorse the purchase of any commercial products or services mentioned in the publication.

: Disclosure of potential conflict of interest: L. A. Darrow and M. Klein have received research support from the National Institute of Environmental Health Sciences, the US Environmental Protection Agency (EPA), the Electric Power Research Institute, and the Centers for Disease Control and Prevention (CDC). J. Hess has received research support from the CDC. P. E. Tolbert has received research support from the EPA, the Electric Power Research Institute, the National Institutes of Health, and the CDC. S. E. Sarnat has received research support from the EPA and the Electric Power Research Institute. C. A. Rogers declares that she has no relevant conflicts of interest.

View full text

Asthma and lower airway diseaseAmbient pollen concentrations and emergency department visits for asthma and wheeze

Background

Objective

Methods

Results

Conclusion

Section snippets

Pollen data

Descriptive statistics

Discussion

J Allergy Clin Immunol

Ann Allergy Asthma Immunol

J Allergy Clin Immunol

Curr Opin Immunol

Ann Allergy Asthma Immunol

J Allergy Clin Immunol

Environ Res

Ann Allergy Asthma Immunol

Ann Allergy Asthma Immunol

Tree pollen and hospitalization for asthma in urban Canada

Int Arch Allergy Immunol

Association between airborne pollen and epidemic asthma in Madrid, Spain: a case-control study

Thorax

Association between tree pollen counts and asthma ED visits in a high-density urban center

J Asthma

Short term effects of airborne pollen concentrations on asthma epidemic

Thorax

Role of outdoor aeroallergens in asthma exacerbations: epidemiological evidence

Thorax

Urban air pollution and climate change as environmental risk factors of respiratory allergy: an update

J Investig Allergol Clin Immunol

Asthma and lower airway disease
Ambient pollen concentrations and emergency department visits for asthma and wheeze