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).
CONCLUSION: 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.
