title: Household air pollution following replacement of traditional open fire with an improved rocket type cookstove.
abstract: Cooking with biomass fuel is an important source of household air pollution (HAP) in developing countries, and a leading risk factor for ill-health. Although various designs of "improved cookstoves" (ICS) have been promoted as HAP interventions in these settings, few of them have undergone in-field evaluation, partly due to the challenge of conducting field measurements in remote settings. In this study we assessed the change in carbon monoxide (CO) exposure following the replacement of the traditional three-stone stove with a popular ICS in 49 homes in Western Kenya. We also assessed the suitability of using kitchen CO as a proxy for kitchen PM2.5. Reduction in 48h mean kitchen CO was 3.1ppm (95% CI: -8.1, 1.8) and in personal CO was 0.9ppm (95% CI: -4.3, 2.6) following stove replacements. Overall, 48-h kitchen and personal CO exposures were lower after stove replacement (28% and 12%, respectively) but with wide confidence intervals that also suggested possible increases in exposure. There were statistically significant reductions in peak kitchen and personal CO concentrations represented by the 8-h 95th percentile: reductions of 26.1ppm (95% CI: -44.6, -7.6) and 8.0ppm (95% CI: -12.2, -3.8), respectively. This is equivalent to 53% reduction in kitchen CO and 39% reduction in personal CO. We found good correlation between kitchen CO and PM2.5concentrations overall (r=0.73, n=33 over averaging periods approximating 1day), which varied by time of day and exposure setting. These variations limit the applicability of CO as a proxy measure for PM2.5concentrations. A combination of interventions, including better designed stoves, improved ventilation and cleaner fuels, may be needed to reduce HAP to levels that are likely to improve health.
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, UK; Stockholm Environment Institute, Linnegatan 87D, Box 24218, 10451 Stockholm, Sweden. Electronic address: caroline.ochieng@sei-international.org.
authors.forename: Caroline
authors.initials: C
authors.lastname: Ochieng
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, UK; Environmental Change Department, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Oxon, UK.
authors.forename: Sotiris
authors.initials: S
authors.lastname: Vardoulakis
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Universitat Pompeu Fabra (UPF), CIBER Epidemiología y Salud Pública (CIBERESP), Spain.
authors.forename: Cathryn
authors.initials: C
authors.lastname: Tonne
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D002248:Carbon Monoxide / Q000032:analysis*; D003296:Cooking; D005390:Fires; D006794:Household Articles; D006801:Humans; D007630:Kenya; D052638:Particulate Matter / Q000032:analysis
chemical_list: D052638:Particulate Matter; D002248:Carbon Monoxide
keywords: Biomass fuel use; Carbon monoxide; Household air pollution; Improved cookstoves; Kenya; Particulate matter