2013 Environment and Health - Basel
AN INITIAL ASSESSMENT OF WINTER TRENDS IN INDOOR PARTICULATE POLLUTION (PM2.5) IN THE GER REGION OF ULAANBAATAR, MONGOLIA
Background: Ulaanbaatar (UB) is home to 40% of Mongolia's 2.74 million residents and growing. A population boom combined with long heating seasons (~ 8 mo.), frequent temperature inversions, and a valley topography has led to dangerously high levels of PM2.5. For example, average wintertime PM2.5 concentrations in 2009-2010 were measured at 250 µg/m3. It is expected that such levels likely result in substantial increases in mortality and morbidity. It is also expected that indoor exposures contribute heavily to total exposure of PM2.5, as approximately half of UB's residents live in yurt-like gers and rely on a mix of dirty solid fuels (coal and wood) in poorly-combusting stoves to meet their heating needs.
Aims: We undertook a pilot study of indoor and outdoor PM2.5 concentrations at ger homes using one of three stove types: a traditional coal stove, an "improved" coal stove (jointly subsidized by the US Millennium Challenge Corp. and the Mongolian government), and a locally piloted stove fueled by a coal-to-gas fuel called dimethyl ether (DME). In addition to validating PM2.5 monitoring methodologies for harsh winter environments (-40C), we explored the relationships between indoor and outdoor PM2.5 concentrations in the ger region of UB.
Methods: Continuous PM2.5 and stove-use data were used to relate indoor and outdoor concentrations with household heating practices. At each of our sample gers, we placed one UC Berkeley Particle and Temperature Sensor (UCB-PATS) outside, one UCB-PATS inside the stove room (used for sleeping, eating, cooking, and general socializing), and fit all appliances that may emit considerable PM2.5 with UC Berkeley Stove Use Monitoring Sensors (SUMS). UCB-PATS were calibrated in field with filter colocations. Results &
Conclusions: Filter samples collected during instrument calibration demonstrate 24-hr average PM2.5 concentrations as high as 610 µg/m3 (outdoor) and 275 µg/m3 (indoor), and 12-hr averages as high as 490 µg/m3 (indoor). Results by stove type, temperature, and other parameters will be presented.