title: Association between wheeze and selected air pollution sources in an air pollution priority area in South Africa: a cross-sectional study.
abstract: BACKGROUND
  An association between wheeze (a symptom of asthma) and environmental tobacco smoke (ETS), types of fuel used for residential heating or cooking and the frequency of trucks passing near homes, has been reported mainly in developed countries. Little is known about the strength of such associations in developing countries. This study was conducted in residential areas situated in Ekurhuleni Metropolitan Municipality, namely Tembisa and Kempton Park, which form part of the Highveld region, a priority area in terms of air pollution in South Africa.
  
  
  METHODS
  From 3764 eligible school children, aged between 13 and 14 years, from 16 selected high schools in the study area, 3468 completed a modified questionnaire based on the International Study of Asthma and Allergies in Childhood (ISAAC). Data were analysed using multiple logistic regression models.
  
  
  RESULTS
  The results are based on data from 3424 children. In the adjusted models, exposure to ETS at school was associated with wheeze ever (OR 1.22 95% CI: 1.03 - 1.45) and current wheeze (OR 1.33 95% CI: 1.08 - 1.64). When gas was most frequently used for residential heating the likelihood of wheeze ever increased by 47% (OR 1.47 95% CI: 1.15 - 1.88). Trucks passing near homes for almost the whole day during weekdays, increased the likelihood of wheeze ever (OR 1.32 95% CI: 1.01 - 1.73), current wheeze (OR 1.61 95% CI: 1.15 - 2.24) and current severe wheeze (OR 2.22 95% CI: 1.28 - 3.77). When data were stratified according to residential area, for children living in Tembisa, ETS exposure at home was associated with current wheeze (OR 1.36 95% CI: 1.06 - 1.77); gas most frequently used for residential heating was associated with wheeze ever (OR 1.68 95% CI: 1.23 - 2.28) and current wheeze (OR 1.61 95% CI: 1.08 - 2.39); paraffin most frequently used for residential heating was associated with current severe wheeze (OR 1.85 95% CI: 1.04 - 3.28).
  
  
  CONCLUSIONS
  It was concluded that children living in one of the air pollution priority areas of South Africa, have an increased risk of wheezing due to exposure to both indoor and outdoor air pollution sources.
authors.affiliation: Department of Environmental Health, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa. shirindej@tut.ac.za.
authors.forename: Joyce
authors.initials: J
authors.lastname: Shirinde
authors.forename: Janine
authors.initials: J
authors.lastname: Wichmann
authors.forename: Kuku
authors.initials: K
authors.lastname: Voyi
mesh_terms: D000293:Adolescent; D000397:Air Pollution / Q000009:adverse effects*; D003296:Cooking; D003430:Cross-Sectional Studies; D005260:Female; D006361:Heating; D006798:Housing; D006801:Humans; D008297:Male; D016017:Odds Ratio; D015995:Prevalence; D012135:Respiratory Sounds / Q000209:etiology*; D012574:Schools; D012906:Smoke / Q000009:adverse effects*; D013019:South Africa / Q000453:epidemiology; D001335:Vehicle Emissions / Q000633:toxicity*
chemical_list: D012906:Smoke; D001335:Vehicle Emissions