ABSTRACT

Open burning of crop residues and specially paddy rice straw is still extensively practiced in many parts of the world today as a cheap mean of disposal of agricultural wastes, land cleansing and also for recovering some soil nutrients. Emission from this incomplete combustion has potential effects on air quality, health and climate. In this study, the characterization of open rice straw burning emission is conducted though field sampling and controlled laboratory burning. Source emission profiles and emission factors were obtained for the following pollutants: particulate matter mass, element composition, EC/OC, levoglucosan and methoxy compounds; PAH, pesticides and PCB, in gas and PM phases; aldehydes, BTX and other VOC urban toxics as well as selected VOC signatures for biomass burning. There is a good correlation between hot spots counting on MODIS satellite images for Pathumthani and ambient air concentrations of PM10 (0.77) and CO (0.56) monitored at a station in the area. Forward trajectories using the HYSPLIT model show that dispersion biomass burning smoke may affect neighboring areas especially the Bangkok Metropolitan Region (BMR). Large amount of emission from annual burning of rice straw in developing countries may seriously affect air quality, health and climate, which calls for public attention and effective management measures.