Association between wheeze and selected air pollution sources in an air pollution priority area in South Africa: a cross-sectional study

Abstract

BackgroundAn 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.MethodsFrom 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.ResultsThe 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).ConclusionIt 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.

Risk factors for asthma among schoolchildren who participated in a case-control study in urban Uganda

“…Our observation that children with asthma were more likely to have parents with tertiary education and to use gas or electricity for indoor cooking (as opposed to charcoal stoves) has been made by an earlier study in Uganda (14). Similarly, our finding that children with asthma reported the highest frequency of 'trucks passing on the street near their home' has been reported elsewhere (34)(35)(36). We suggest that these factors are proxy measures of a higher socio-economic status of asthma cases and of urbanicity, consistent with findings from other LMICs that have found a higher prevalence of asthma among children (and adults) in urban than rural areas (7,37,38).…”

The association between environmental tobacco smoke exposure and childhood respiratory disease: a review

“…Another African study assessing the effects of pollution from ETS, cooking, and heating fuels and outdoor traffic found an increased risk of wheezing from both indoor and outdoor air pollution sources. ETS exposure at home was associated with current wheeze (OR 1.36 95% CI: 1.06−1.77); use of gas for residential heating was associated with wheeze ever (OR 1.68 95% CI: 1.23−2.28) or 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) [104]. The risk of LRTI mortality in LMIC is also increased by environmental exposures including ETS (OR 1.52, 95% CI 1.20–1.93) or IAP (OR 3.02, 95% CI 2.11‒4.31) [105].…”

A policy review of synergies and trade-offs in South African climate change mitigation and air pollution control strategies

“…Ambient -especially indoor -air pollution, are major public health issues. Local air pollution increases the risk of acute respiratory tract infections and pneumonia, especially in children of low-income communities-in 2012 the pneumonia incidence rate for children under five years was 66.8 out of 1000 5 , and an increased risk of wheezing for children due to outdoor and indoor air pollution was found in the Child Highveld Priority Area Study (Shirinde et al, 2014).…”

“…Local air pollution is another pressing issue due to its negative health impacts (Norman et al, 2007;Matinga et al, 2014;Shirinde et al, 2014). Electricity generation, industrial processes, domestic energy use and vehicular exhaust emissions are the main contributors to air pollution in South Africa (Scorgie et al, 2004).…”

“…Local air pollution disproportionally affects poorer (historically disadvantaged black) communities that are located close to industries (Dugard and Alcaro, 2013). Use of inferior quality fuel burning appliances expose these communities to concentrations of smoke and carbon monoxide that cause adverse health effects (Shirinde et al, 2014). Furthermore, poorer households are likely to be more vulnerable to adverse effects of climate change, a consideration that has been taken into account in South African climate change adaptation strategies (DEA, 2013).…”