title: [Study of recent yearly trend of increase in airborne pollen of Japanese cedar and cypress pollen].
abstract: BACKGROUND
  Based on epidemiological studies of prevalence, sensitization as well as pollen survey, it is presumed that airborne Japanese cedar pollen (JCP) and cypress (JCyP) have increased progressively for past 40 years. However, because of their large yearly variations, accurate objective and scientific study is required to confirm if it is true or not.
  
  
  METHODS
  We analyzed the time trends of JCP and JCy separately in 11 districts throughout Japan where have records of continuous past survey from 1986 to 2005, by regression analysis using net pollen count and their 3 and 5 running means.
  
  
  RESULTS
  When significant slope of regression line (regression coefficient) is assumed as p < 0.05 and R2 (coefficient of determination) >0.4, significant increase in airborne pollen was revealed in the use of 5 point running mean (6 districts of total 11 in JCP and 5 in JCyP) but not net count or 3 point running mean because of correction of statistic error due to large yearly variations. This study suggested that our method used for analysis of a recent increase in airborne JCP and JCyP was useful and scientific.
authors.affiliation: Japan Allergy & Asthma Clinic.
authors.forename: Minoru
authors.initials: M
authors.lastname: Okuda
authors.forename: Atusi
authors.initials: A
authors.lastname: Usami
authors.forename: Reiko
authors.initials: R
authors.lastname: Kisikawa
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D032485:Cryptomeria; D029781:Cupressus; D016021:Epidemiologic Studies; D007564:Japan; D011058:Pollen / Q000276:immunology; D012044:Regression Analysis
chemical_list: D000393:Air Pollutants