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The exposure of infants and children to carbon monoxide from biomass fuels in The Gambia: a measurement and modeling study


Smoke from biomass fuels is a risk factor for pneumonia, the leading cause of child death worldwide. Although particulate matter (PM) is the metric of choice for studying the health effects of biomass smoke, measuring children's PM exposure is difficult. Carbon monoxide (CO), which is easier to measure, can be used as a proxy for PM exposure. We measured the exposure of children ≤5 years of age in The Gambia to CO using small, passive, color stain diffusion tubes. We conducted multiple CO measurements on a subset of children to measure day-to-day exposure variability. Usual CO exposure was modeled using a mixed effects model, which also included individual and household level exposure predictors. Mean measured CO exposure for 1181 children (n=2263 measurements) was 1.04±1.46 p.p.m., indicating that the Gambian children in this study on average have a relatively low CO exposure. However, 25% of children had exposures of 1.3 p.p.m. or higher. CO exposure was higher during the rainy months (1.33±1.62 p.p.m.). Burning insect coils, using charcoal, and measurement done in the rainy season were associated with higher exposure. A parsimonious model with fuel, season, and other PM sources as covariates explained 39% of between-child variation in exposure and helped remove within-child variability.

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This work was supported by a grant from the National Institute of Environmental Health Sciences (1R21ES017855-01). We thank the households who participated in the study for their help and hospitality, our field workers and field supervisors for valuable assistance in data collection, the Biomedical Engineering Department at the MRC for technical assistance throughout the study, Jose Vallarino for information on methods and instruments for personal exposure measurement, and Mariel Finucane for advice on presentation of statistical results. We also thank Grant Mackenzie for operational support, Kim Mulholland, Philip Hill, Brian Greenwood, and Peter Smith for advice on case–control study design, and Nigel Bruce and Kirk Smith for advice on exposure measurement.

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Correspondence to Majid Ezzati.

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Dionisio, K., Howie, S., Dominici, F. et al. The exposure of infants and children to carbon monoxide from biomass fuels in The Gambia: a measurement and modeling study. J Expo Sci Environ Epidemiol 22, 173–181 (2012).

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  • indoor air pollution
  • biomass fuels
  • global health
  • Africa
  • carbon monoxide
  • exposure assessment

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