title: Association between tree pollen counts and asthma ED visits in a high-density urban center.
abstract: BACKGROUND
  Asthma exacerbation patterns are cyclic in nature and often correlate with air particle concentrations.
  
  
  OBJECTIVE
  To examine the relationship between asthma-related emergency department (ED) visits and outdoor air quality for pediatric and adult patients in a high asthma prevalence area, the New York City borough of the Bronx.
  
  
  METHODS
  Numbers of daily asthma-related adult and pediatric ED visits during one complete year (1999) were obtained from the seven major Bronx hospitals. Daily values of nitrogen oxides (NO(x)), ozone (O(3)), sulfur dioxide (SO(2)), and pollen counts were acquired.
  
  
  RESULTS
  Asthma-related ED visit numbers were highest in December-January and lowest in July. There were three distinct peaks of increased asthma ED visits: winter (December-January), spring (late April-May), and fall (October). The spring peak was the most striking and coincided with high tree pollen counts (tree pollen: r = 0.90, p = .03). We observed a positive correlation between asthma ED visits in the winter and SO(2) and NO(x) levels. Winter peaks of SO(2) and NO(x) in early December appeared to precede the winter asthma peak.
  
  
  CONCLUSIONS
  The spring asthma peak is closely associated with increased tree pollen counts, and the asthma increase at this time is likely due to allergic reactions to pollen. No significant associations could be established with the fall peak. The winter peak correlates with elevated SO(2) and NO(x) levels.
authors: Department of Medicine, Allergy/Immunology Division, Albert Einstein College of Medicine, Bronx, New York 10463, USA. sjariwal@montefiore.org
authors: Sunit P
authors: SP
authors: Jariwala
authors: Satya
authors: S
authors: Kurada
authors: Heather
authors: H
authors: Moday
authors: Andy
authors: A
authors: Thanjan
authors: Laurel
authors: L
authors: Bastone
authors: Moisey
authors: M
authors: Khananashvili
authors: Jason
authors: J
authors: Fodeman
authors: Golda
authors: G
authors: Hudes
authors: David
authors: D
authors: Rosenstreich
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000397:Air Pollution / Q000009:adverse effects* / Q000706:statistics & numerical data; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018450:Disease Progression; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009519:New York City / Q000453:epidemiology; D009569:Nitric Oxide / Q000032:analysis; D010126:Ozone / Q000032:analysis; D011058:Pollen / Q000009:adverse effects* / Q000276:immunology; D012307:Risk Factors; D012621:Seasons; D017678:Sex Distribution; D013458:Sulfur Dioxide / Q000032:analysis; D014197:Trees; D014505:Urban Population; D055815:Young Adult
chemical_list: D013458:Sulfur Dioxide; D009569:Nitric Oxide; D010126:Ozone