Emission of Air Pollutants from Rice Residue Open Burning in Thailand, 2018

Crop residue burning negatively impacts both the environment and human health, whether in the aspect of air pollution, regional and global climate change, or transboundary air pollution. Accordingly, this study aims to assess the level of air pollutant emissions caused by the rice residue open burning activities in 2018, by analyzing the remote sensing information and country specific data. This research also aims to analyze the trend of particulate matter 10 microns or less in diameter (PM10) concentration air quality sites in provinces with large paddy rice planting areas from 2010-2017. According to the results, 61.87 megaton (Mt) of rice residue were generated, comprising 21.35 Mt generated from the irrigated fields and 40.53 Mt generated from the rain-fed field. Only 23.0% of the total rice residue generated were subject to open burningof which nearly 32% were actually burned in the fields. The emissions from such rice residue burning consisted of: 5.34 +/- 2.33 megaton (Mt) of CO2, 44 +/- 14 kiloton (kt) of CH4, 422 +/- 179 kt of CO, 2 +/- 2 kt of NOX, 2 +/- 2 kt of SO2, 38 +/- 22 kt of PM2.5, 43 +/- 29 kt of PM10, 2 +/- 1 kt of black carbon (BC), and 14 +/- 5 kt of organic carbon (OC). According to the air quality trends, the results shows the higher level of PM10 concentration was due to the agricultural burning activities, as reflected in the higher monthly averages of the months with the agricultural burning, by around 1.9-2.1 times. The result also shows the effect of government's policy for farmers on the crop burning activities and air quality trends.