Home environment and indoor air pollution exposure in an African birth cohort study

Background: Household indoor air pollution (IAP) is a global health problem and a risk factor for childhood respiratory disease; the leading cause of mortality in African children. This study aimed to describe the home environment and measure IAP in the Drakenstein Child Health Study (DCHS), an African birth cohort.

Methods: An antenatal home visit to assess the home environment and measure IAP (particulate matter, sulphur dioxide, nitrogen dioxide, carbon monoxide and volatile organic compounds (VOCs)) was done on pregnant women enrolled to the DCHS, in a low-socioeconomic, peri-urban South African community. Urine cotinine measured maternal tobacco smoking and exposure. Dwellings were categorised according to 6 household dimensions. Univariate and multivariate analysis explored associations between home environment, seasons and IAP levels measured.

Results: 633 home visits were completed, with IAP measured in 90% of homes. Almost a third of participants were of the lowest socio-economic status and the majority of homes (65%) lacked 2 or more of the dwelling category dimensions. Most households had electricity (92%), however, fossil fuels were still used for cooking (19%) and heating (15%) in homes. Antenatal maternal smoking prevalence was 31%; 44% had passive smoke exposure. Of IAP measured, benzene (VOC) was significantly above ambient standards with median 5.6 μg/m3 (IQR 2.6-17.1). There were significant associations between the use of fossil fuels for cooking and increased benzene [OR 3.4 (95% CI 2.1-5.4)], carbon monoxide [OR 2.9 (95% CI 1.7-5.0)] and nitrogen dioxide [OR 18.6 (95% CI 3.9-88.9)] levels. A significant seasonal association was found with higher IAP levels in winter.

Conclusion: In this low-socioeconomic African community, multiple environmental factors and pollutants, with the potential to affect child health, were identified. Measurement of IAP in a resource-limited setting is feasible. Recognising and quantifying these risk factors is important in effecting public health policy changes.