title: Association of indoor air quality and preschool children's respiratory symptoms.
abstract: BACKGROUND
  This study aimed to assess the association between exposure to indoor air pollution in DCCs (Child Day Care Centers) and the respiratory symptoms of children under 6 years old.
  
  
  METHODS
  Air quality data were collected three times regarding to seasonal variation. Pollutants measured in 11 DCCs included PM₁₀, CO, NO₂, SO₂, O₃, benzene, bacteria, fungi, and dust mite. The frequencyof respiratory symptoms including coughing, rhinitis, and dyspnea were recorded via teacher and parent-report questionnaires. Fractional exhaled nitric oxide (FENO) levels were measured to assess airway inflammation.
  
  
  RESULTS
  436 children participated in the study. 83% completed data collection in all 3 seasons. The frequency of rhinitis correlated with PM₁₀ (IRR=70.3, 95%CI=12.4-399.7, p<0.001), CO (IRR=3.2, 95%CI=2.4-4.2, p<0.001), benzene (IRR=2.3, 95%CI=1.8-3.2, p<0.001) and D.Pteronyssinus level (IRR=2.1, 95%CI=1.7-2.7, p<0.001). The frequency of coughingcorrelated with levels of PM10 (IRR=15.2, 95%CI=3.0-78.2, p<0.001), CO (IRR=2.8, 95%CI=2.1-3.7, p<0.001), benzene (IRR=1.4, 95%CI=1.1-1.9, p=0.02). The frequency of dyspnea correlated with D.Pteronyssinus level (IRR=3.9, 95%CI=1.7-9.1, p=0.001). FENO levels associated with high benzene levels (OR=5.9, 95%CI=1.5-22.9, p=0.01). The majority of DCCs had at least one PM₁₀ measurement above the standard level, and these high levels were noted in all 3 seasons. Three DCCs had PM₁₀ levels above the standard level in all seasons. 64% of the DCCs had indoor bacterial counts above the standard level in all seasons.
  
  
  CONCLUSIONS
  PM₁₀ and bacterial count is a significant problem in Bangkok metropolitan DCCs. The respiratory symptoms of children positively associated with PM₁₀, CO, benzene and dust mite levels.
authors.affiliation: Department of Pediatrics, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Sirinapa
authors.initials: S
authors.lastname: Siwarom
authors.affiliation: Department of Pediatrics, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Pongtong
authors.initials: P
authors.lastname: Puranitee
authors.affiliation: Department of Pediatrics, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Adisak
authors.initials: A
authors.lastname: Plitponkarnpim
authors.affiliation: Department of Pediatrics, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Wiparat
authors.initials: W
authors.lastname: Manuyakorn
authors.affiliation: Department of Pediatrics, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Ratchaneewan
authors.initials: R
authors.lastname: Sinitkul
authors.affiliation: Department of Pediatrics, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Sakda
authors.initials: S
authors.lastname: Arj-Ong Vallipakorn
mesh_terms: D000367:Age Factors; D000393:Air Pollutants / Q000009:adverse effects; D000397:Air Pollution; D016902:Air Pollution, Indoor / Q000009:adverse effects; D002675:Child, Preschool; D004781:Environmental Exposure; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000032:analysis; D016017:Odds Ratio; D011159:Population Surveillance; D012140:Respiratory Tract Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D012621:Seasons; D063189:Symptom Assessment; D013785:Thailand / Q000453:epidemiology
chemical_list: D000393:Air Pollutants; D009569:Nitric Oxide