title: Biomass fuel exposure and asthma symptoms among rural school children in Nigeria.
abstract: BACKGROUND
  Approximately 70% of rural Nigerian households rely on biomass fuels for cooking. The International Study of Asthma and Allergies in Childhood (ISAAC) estimates the prevalence of current wheeze among children in Nigeria to have risen from 10.7% in 1999 to approximately 20% in 2014.
  
  
  OBJECTIVE
  To examine the effects of biomass smoke exposure on asthma symptom prevalence in rural children in Nigeria.
  
  
  METHODS
  We conducted a cross-sectional survey in rural communities in Nigeria. Asthma symptoms were defined according to ISAAC definitions. Biomass smoke exposure was determined by the types of fuel used for cooking. Logistic regression was used to explore associations between biomass smoke and asthma symptoms.
  
  
  RESULTS
  The study population comprised 1,690 school children, of which 865 lived in households cooking with biomass and 825 lived in households not using biomass. Asthma symptoms were reported in 481 (28.5%) children. Biomass fuel was associated with increased odds of asthma symptoms. Adjusted odds ratios (aORs) were 1.38 (95% CI: 1.05-1.80) for nocturnal cough, 1.26 (95% CI: 1.00-1.61) for current wheeze, and 1.33 (95% CI: 1.05-1.69) for report of any asthma-related symptoms. Sex modified the associations between asthma symptoms with biomass fuel: aORs were stronger and significant for males (nocturnal cough = 1.85, 95% CI: 1.24-2.76; current wheeze = 1.48, 95% CI: 1.03-2.13; report of any asthma-related symptoms = 1.60, 95% CI: 1.12-2.28), but weaker and non-significant for females.
  
  
  CONCLUSIONS
  The risk of asthma symptoms related to biomass smoke exposure appears to differ by sex.
authors: a Community Health and Epidemiology and the Canadian Centre for Health and Safety in Agriculture, College of Medicine, University of Saskatchewan , Saskatoon , SK , Canada.|d Department of Medicine and The Center for Global Health , University of Chicago , IL , USA.
authors: Oluwafemi
authors: O
authors: Oluwole
authors: b College of Medicine, University of Ibadan , Ibadan , Oyo State , Nigeria.
authors: Ganiyu O
authors: GO
authors: Arinola
authors: c Department of Public Health Science , University of Chicago , Chicago , IL , USA.
authors: Dezheng
authors: D
authors: Huo
authors: d Department of Medicine and The Center for Global Health , University of Chicago , IL , USA.
authors: Christopher O
authors: CO
authors: Olopade
mesh_terms: D000293:Adolescent; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D003296:Cooking / Q000379:methods*; D003371:Cough; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009549:Nigeria / Q000453:epidemiology; D015995:Prevalence; D012135:Respiratory Sounds; D012424:Rural Population / Q000706:statistics & numerical data*; D012737:Sex Factors; D012906:Smoke / Q000009:adverse effects*; D012959:Socioeconomic Factors; D055815:Young Adult
chemical_list: D012906:Smoke
keywords: Asthma symptoms; Nigeria; biomass fuel; rural; school children