Particulate matter and carbon monoxide in highland Guatemala: Indoor and outdoor levels from traditional and improved wood stoves and gas stoves

Area 22-h average carbon monoxide (CO), total suspended particulates (TSP), particles less than 10 mu m in diameter (PM10), and particles less than 2.5 mu m in diameter (PM2.5) measurements were made in three test homes of highland rural Guatemala in kitchens, bedrooms, and outdoors on a longitudinal basis, i.e. before and after introduction of potential exposure-reducing interventions. Four cookstove conditions were studied sequentially: background (no stove in use); traditional open woodstove, improved woodstove with flue (plancha), and bottled-gas (LPG) stove. With nine observations each, kitchen PM2.5 levels were 56 mu g/m(3) under background conditions, 528 mu g/m(3) for open fire conditions, 96 mu g/m(3) for plancha conditions, and 57 mu g/ m(3) for gas stove conditions. Corresponding PM10/TSP levels were 173/174, 717/836, 210/276, 186/218 mu g/m(3). Corresponding CO levels were 0.2, 5.9, 1.4, 1.2 ppm. Comparisons with other studies in the area indicate that the reductions in indoor concentrations achieved by improved wood-burning stoves deteriorate with stove age. Mother and child personal CO and PM2.5 measurements for each stove condition demonstrate the same trend as area measurements, but with less differentiation.