title: Occurrence of farmer's lung disease is relevant to meteorological conditions: a 20-year follow-up field survey analysis.
abstract: BACKGROUND
  A field survey on farmer's lung disease (FLD) in a dairy farming community in the northernmost district of Japan has been in progress since 1978.
  
  
  METHODS
  The correlation between the number of FLD occurrences year by year and dairy farming conditions and meteorological data were compared.
  
  
  RESULTS
  Thirty-four FLD cases had occurred in a 20 years period. Average number of days below freezing during the harvest season the year prior to FLD occurrence were significantly smaller than other years (2.1 +/- 0.7 [SE] days, 4.6 +/- 0.7 days, P < 0.05, respectively). Average annual sum of the sunlight hours in the years before the years with FLD occurrence was significantly smaller than those without FLD occurrence (1457.1 +/- 114.0 hr, 1811.3 +/- 97.7 hr, P < 0.05, respectively) and was also significantly smaller for the sunlight hours during a harvest season (821.9 +/- 60.2 hr, 1023.2 +/- 52.7 hr, P < 0.05, respectively).
  
  
  CONCLUSIONS
  Temperature and sunlight hours closely associated with the FLD occurrence.
authors.affiliation: First Department of Medicine, School of Medicine, Hokkaido University, Sapporo, Japan. toruchan@sapmed.ac.jp
authors.forename: Toru
authors.initials: T
authors.lastname: Takahashi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ohtsuka
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Munakata
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Nasuhara
authors.forename: Atsuko
authors.initials: A
authors.lastname: Kamachi-Satoh
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Homma
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kawakami
mesh_terms: D003612:Dairying; D005203:Farmer's Lung / Q000453:epidemiology* / Q000517:prevention & control; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008397:Masks; D015999:Multivariate Analysis; D011891:Rain; D012307:Risk Factors; D012621:Seasons; D018709:Statistics, Nonparametric; D013472:Sunlight; D013696:Temperature