Pneumonia and Exposure to Household Air Pollution in Children Under the Age of 5 Years in Rural Malawi: Findings From the Cooking and Pneumonia Study.
Kevin Mortimer, Maia Lesosky, Sean Semple, Jullita Malava, Cynthia Katundu, Amelia Crampin, Duolao Wang, William Weston, Dan Pope, Deborah Havens, Stephen B Gordon, John Balmes
Author Information
Kevin Mortimer: Liverpool School of Tropical Medicine, Liverpool, UK. Electronic address: Kevin.mortimer@lstmed.ac.uk.
Maia Lesosky: University of Cape Town, Cape Town, South Africa.
Sean Semple: Stirling University, Stirling, UK.
Jullita Malava: Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi.
Cynthia Katundu: Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi.
Amelia Crampin: Malawi Epidemiology and Intervention Research Unit, Chilumba, Malawi; London School of Hygiene and Tropical Medicine, London, UK.
Duolao Wang: Liverpool School of Tropical Medicine, Liverpool, UK.
William Weston: Liverpool School of Tropical Medicine, Liverpool, UK.
Dan Pope: University of Liverpool, Liverpool, UK.
Deborah Havens: Liverpool School of Tropical Medicine, Liverpool, UK.
Stephen B Gordon: Liverpool School of Tropical Medicine, Liverpool, UK; Malawi Liverpool Wellcome Trust Programme, Blantyre, Malawi.
John Balmes: University of California, Berkeley, CA; University of California, San Francisco, San Francisco, CA.
BACKGROUND: Exposure to household air pollution is associated with an increased risk of pneumonia in children in low- and middle-income countries; however, exposure-response data are limited, and there are uncertainties around the extent to which biomass-fueled cookstoves can reduce these exposures. RESEARCH QUESTION: What is the association between exposure to household air pollution and pneumonia in children under the age of 5 years in rural Malawi and what are the effects of a biomass-fueled cookstove intervention on personal exposure to household air pollution? STUDY DESIGN AND METHODS: We measured personal exposure to carbon monoxide (CO; 48 hours of continuous measurement and transcutaneous carboxyhemoglobin) every 6 months in children who participated in a cluster-randomized controlled trial of a cleaner burning biomass-fueled cookstove intervention to prevent pneumonia in children under the age of 5 years in rural Malawi (the Cooking And pneumonia Study). Exposure-response and multivariable analyses were done. RESULTS: We recruited 1805 (928 intervention; 877 control) children (mean age, 25.6 months; 50.6% female). We found no evidence of an association between exposure to CO (incident rate ratio, 1.0; 95% CI, 0.967 to 1.014; P = .53) or carboxyhemoglobin (incident rate ratio, 1.00; 95% CI, 0.993 to 1.003; P = .41) in children who experienced pneumonia vs those who did not. Median exposure to CO in the intervention and control groups was was 0.34 (interquartile range, 0.15 to 0.81) and 0.37 parts per million (interquartile range, 0.15 toa 0.97), respectively. The group difference in means was 0.46 (95% CI, -0.95 to 0.012; P = .06). INTERPRETATION: Exposure to CO in our population was low with no association seen between exposure to CO and pneumonia incidence and no effect of the Cooking And pneumonia Study intervention on these exposures. These findings suggest that CO may not be an appropriate measure of household air pollution exposure in settings such as rural Malawi and that there is a need to develop ways to measure particulate matter exposures directly in young children instead. CLINICAL TRIAL REGISTRATION: ISRCTN59448623.
