Measuring the Exposure of Infants and Children to Indoor Air Pollution From Biomass Fuels in the Gambia

Abstract

O-30C3-2 Background/Aims: Smoke from biomass fuels contains multiple gaseous and particulate pollutants, and is a risk factor for pneumonia, the leading cause of child death worldwide. Few studies have assessed the exposure-response relationship for biomass smoke and pneumonia, primarily because measuring children's exposure is difficult, especially for particulate matter (PM). We report on a study which utilized multiple methods to evaluate children's exposure to PM and carbon monoxide (CO) from biomass fuels. Methods: Seventy-two hours personal CO exposure was measured for 1200 children, with 12%–15% receiving an additional 3–4 CO measurements. In the same subset of children, 72-hours integrated and continuous PM and 72-hours CO were measured in the cookhouse. Personal PM exposure was measured for 20–25 of these children. Usual personal exposure to CO is estimated using a random effects model including child- and household-level covariates. Personal exposure of children to PM is estimated using 3 different approaches, as well as a combined model: (1) combining time-location-activity budget with microenvironment PM; (2) estimating PM exposure using CO exposure combined with stationary CO-PM relationship; and (3) direct measurement of personal PM. Results: Preliminary results show a mean 72-hours CO exposure on children of 1.0 ± 1.3 ppm, with an age distribution of 0.8 ± 0.9 ppm (0–11 months) and 1.1 ± 1.5 ppm (12–59 months). Regression analysis adjusting for child's age, study site, and sex indicates a seasonal pattern for CO exposure, with significantly higher exposure in July, August, and September. Using the CO-PM relationship from a pilot study, estimated average personal PM2.5 exposure for these children would be 189 μg/m3. Conclusion: Children's exposure to PM2.5 in The Gambia is well above WHO Air Quality Guidelines. The results of multiple measurement methods can be combined to estimate children's personal PM2.5 exposure.