Abstract:

Open burning of crop residues is still extensively practiced in many parts of the world today as a cheap mean of disposal of agricultural wastes and also for recovering some soil nutrients. Emission from this incomplete combustion has adverse effects on air quality, health and climate. In many parts of Asia, where rice is the major agricultural crop, open burning of harvested paddies is increasingly practiced, which is a consequence of increasing growing areas as well as the higher living standards of farmers who stop using rice straw as domestic fuel or feedstock. A study on air pollution emitted from open rice straw burning has been conducted at the Asian Institute of Technology in the past 4 years though field sampling and laboratory experiments with the aim to provide a comprehensive assessment of effects. Results show high emission of toxic air pollutants including fine particulate matter, carcinogenic polycyclic aromatic hydrocarbons, pesticides and PCB, and a range of volatile organic compounds including aldehydes and BTEX. Emission input has been prepared for modeling the impacts on air quality in Bangkok Metropolitan Region by CAMx and CMAQ/MM5. Receptor modeling using the obtained source profiles reveals that the open burning contributes around 25-30% to PM2.5 pollution in Bangkok. Exposure to burning smoke is investigated using personal monitoring and modeling. Measurements are extended to include climate change properties of the emission including EC/OC, water uptake and light absorption. The findings would provide scientific basis for developing sustainable agroresidue management strategies.

Presentation: http://www.cleanairnet.org/baq2006/1757/docs/SW13_1.ppt