title: The association between endotoxin and lung function among children and adolescents living in a rural area.
abstract: BACKGROUND⁄
  
  
  OBJECTIVE
  Knowledge of the effects of domestic endotoxin on children's lung function is limited. The association between domestic endotoxin and asthma or wheeze and lung function among school-age children (six to 18 years of age) was examined. The interaction between endotoxin and other personal and environmental characteristics and lung function was also assessed.
  
  
  METHODS
  A case-control study was conducted in and around the rural community of Humboldt, Saskatchewan, between 2005 and 2007. Parents of cases reported either doctor-diagnosed asthma or wheeze in the previous year. Controls were randomly selected from those not reporting these conditions. Data were collected by questionnaire to ascertain symptoms and conditions, while spirometry was used to measure lung function including forced vital capacity and forced expiratory volume in 1 s. Dust collected from the child's play area floor and the child's mattress was used to quantify endotoxin, and saliva was collected to quantify cotinine levels and assess tobacco smoke exposure.
  
  
  RESULTS
  There were 102 cases and 207 controls included in the present study. Lower forced expiratory volume in 1 s was associated with higher mattress endotoxin load among female cases (beta=-0.25, SE=0.07 [P<0.01]). There was a trend toward lower forced vital capacity, which was associated with higher play area endotoxin load among cases with high tobacco smoke exposure (beta=-0.17, SE=0.09 [P<0.10]).
  
  
  CONCLUSIONS
  Findings indicated that high endotoxin levels present in common household areas of rural children with asthma or wheeze may also affect their lung function. These associations may be potentiated by tobacco smoke exposure and female sex.
authors.affiliation: Canadian Centre for Health and Safety in Agriculture, University of Saskatchewan, Saskatoon, Canada. josh.lawson@usask.ca
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Lawson
authors.forename: James A
authors.initials: JA
authors.lastname: Dosman
authors.forename: Donna C
authors.initials: DC
authors.lastname: Rennie
authors.forename: Jeremy
authors.initials: J
authors.lastname: Beach
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Newman
authors.forename: Ambikaipakan
authors.initials: A
authors.lastname: Senthilselvan
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000209:etiology*; D016022:Case-Control Studies; D002648:Child; D003367:Cotinine / Q000032:analysis; D003430:Cross-Sectional Studies; D004391:Dust / Q000032:analysis; D004731:Endotoxins / Q000009:adverse effects* / Q000032:analysis; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D005260:Female; D005541:Forced Expiratory Volume; D006306:Health Surveys; D006801:Humans; D008297:Male; D012044:Regression Analysis; D012135:Respiratory Sounds / Q000209:etiology*; D012423:Rural Health; D012463:Saliva / Q000737:chemistry; D012525:Saskatchewan; D012737:Sex Factors; D013147:Spirometry; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects / Q000032:analysis; D014797:Vital Capacity
chemical_list: D004391:Dust; D004731:Endotoxins; D014028:Tobacco Smoke Pollution; D003367:Cotinine