Spatial and Temporal Variations of PM10 Concentrations over a Mineral Products Industrial Area in Saraburi

Abstract

The observational data set of ambient PM10 concentrations from monitoring stations in Saraburiduring 2001 to 2005 was analyzed to investigate the spatial and temporal variations. The result shows thatNah Phra Laan sub-district and its vicinity, mineral products industrial area in Saraburi, is very serious areafor particulate problem. During 2001-2005, the PM10 concentrations at Nah Phra Laan site exceededannual standard of 50 μg/m3 every year. PM10 levels show strong spatial variation that can be attributed tolow wind speed and coarse particulate matters emitted from crushed stone plants and re-suspended dustfrom roads. The result reveals that local sources are main contributors of PM10 in Nah Phra Laan'satmosphere. Monthly average PM10 concentrations show strong seasonal variation. Annual average PM10concentrations in winter, summer, and rainy season were 102.3±66.0, 80.3±44.8, and 86.8±38.7 μg/m3,respectively. Higher PM10 concentration in winter is due to less precipitation, weaker wind speed, andlower temperature. The diurnal variations of PM10 concentrations characterize by two peaks at around9.00-11.00 AM and 7.00-9.00 PM that are associated with high emission rate and accumulated condition(low wind speed and short mixing height). The difference of diurnal variations in each season is found withthe high variation in winter and the low variation in summer.

Keywords : PM10 / Spatial Variation / Temporal Variation / Saraburi / Mineral Products Industry