Asthma-Related Outcomes Associated with Indoor Air Pollutants from a Survey of School Children Residing in Informal Settlement Households of the Western Cape Province of South Africa

Abstract

The health impact of indoor air pollution in informal settlement households has not been extensively studied in South Africa. This study investigated the association between asthma and common indoor exposures in a survey of school children residing in the Western Cape Province. A total of 590 children, aged 9 – 11 years, were recruited from four informal settlements in the province. The International Study of Asthma and Allergies in Children (ISAAC) questionnaire, was administered to caregivers. Pulmonary function assessment included spirometry and fractional-exhaled nitric oxide (FeNO). Phadiatop test for atopy was done. The prevalence of doctor-diagnosed asthma was 3.4% (n=20) among whom only 50% were on treatment. The prevalence of asthma symptoms (wheezing in the past 12 months) was 12.9% and 17.6% had airway obstruction (FEV1 < lower limit of normal) while 10.2% had airway inflammation (FeNO > 35 ppb). In adjusted logistic regression models, dampness, visible mould growth, paraffin-use for cooking, and passive smoking were associated with a two-fold increased risk in upper and lower airway outcomes. The strongest association was for rhinitis (adjusted odds-ratio – aOR 3.01, 95%CI: 1.45 – 6.15). There is a need for improved diagnosis of childhood asthma and indoor air quality in informal settlement households.