Mobile Monitoring of PM2.5 Spatial Variation in Ulaanbaatar, Mongolia

Mobile Monitoring of PM2.5 Spatial Variation in Ulaanbaatar, MongoliaAbstract Number:2548 Enkhjargal Gombojav*, Enkhmaa Sarangerel, Munkherdene Mendbayar, Jargalsaikhan Ganbold, Bilegerdene Ankhzul, Altangerel Amar, Naransukh Damiran, and Ryan Allen Enkhjargal Gombojav* Health Sciences University of Mongolia, Mongolia, E-mail Address: [email protected] Search for more papers by this author , Enkhmaa Sarangerel National Agency for Meteorology and Environmental Monitoring of Mongolia, Mongolia, E-mail Address: [email protected] Search for more papers by this author , Munkherdene Mendbayar Health Sciences University of Mongolia, Mongolia, E-mail Address: [email protected] Search for more papers by this author , Jargalsaikhan Ganbold Health Sciences University of Mongolia, Mongolia, E-mail Address: [email protected] Search for more papers by this author , Bilegerdene Ankhzul Health Sciences University of Mongolia, Mongolia, E-mail Address: [email protected] Search for more papers by this author , Altangerel Amar Health Sciences University of Mongolia, Mongolia, E-mail Address: [email protected] Search for more papers by this author , Naransukh Damiran Health Sciences University of Mongolia, Mongolia, E-mail Address: [email protected] Search for more papers by this author , and Ryan Allen Simon Fraser University, Canada, E-mail Address: [email protected] Search for more papers by this author AbstractUlaanbaatar, Mongolia’s capital city, has some of the highest fine particulate matter (PM2.5) concentrations in the world due primarily to wintertime coal combustion in gers (traditional Mongolian dwellings) surrounding the city. Other sources include coal-fired power plants and vehicles. The city’s PM2.5 monitoring network is not dense enough to assess PM2.5 spatial variability, limiting exposure assessment in epidemiologic studies and risk assessments of long-term exposure. We sought to assess spatial variability in wintertime PM2.5 using mobile monitoring. Monitoring was conducted during evenings (~22:00 – 1:00) January-March, 2014 by driving a predetermined route (with randomly chosen direction) selected based on local knowledge to capture different land uses and a range of expected PM2.5 concentrations. A nephelometer (Radiance Research M903) recorded the particle light scattering coefficient (bsp) at 15-s averages and a GPS receiver (Garmin 60CSx) recorded the vehicle’s location at 5-s intervals. To isolate spatial variation, a second fixed-site nephelometer was used to adjust for temporal changes and a bsp-PM2.5 conversion was determined by comparing the fixed-site nephelometer data with PM2.5 concentrations at a nearby government monitoring site. The average PM2.5 concentration over the study period was 106 µg/m3. A strong correlation between bsp and PM2.5 (r = 0.95 on a 24-hr basis) supported the use of nephelometers for PM2.5 measurements. Mobile monitoring captured a wide range of concentrations corresponding to approximately 50 – 1000 µg/m3 PM2.5. The highest concentrations were consistently found in the ger neighborhoods. Mobile monitoring shows promise for capturing PM2.5 spatial gradients across highly polluted cities. Incorporation of geographic information systems (GIS) and satellite data into this analysis will facilitate the development of a land use regression model to approximate PM2.5 concentrations throughout the city.