AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
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Oxidative Potential and Chemical Characteristics of Water-soluble Particles Produced by Burning Rice Straw and Pine Wood
LUCILLE JOANNA BORLAZA, Bhuwan Paudel, Arom Seo, KwangYul Lee, HungSoo Joo, Shila Maskey, Kihong Park, Gwangju Institute of Science and Technology, South Korea
Abstract Number: 720 Working Group: Health Related Aerosols
Abstract Fine particulate matter (PM2.5) produced from biomass burning emissions has been increasingly associated with respiratory diseases (Laumbach et al., 2012; Torres-Duque et al., 2008; Arbex et al., 2007). Exposure to PM2.5 has been known to cause adverse health effects through several mechanisms of action including oxidative stress. In lieu of common assessment of PM2.5 health effects, this study investigated the capacity of biomass burning – related PM2.5 to cause oxidative stress through the formation of reactive oxygen species (ROS). Laboratory – generated PM2.5 from burning of rice straw and pine wood was sampled in a controlled volume chamber and collected using URG cyclones on teflon filters at different burning phases (approximately 1- 20 mins, 21- 40 mins, and 41- 60 mins after burning of sample). Particle size distribution and mass concentration was monitored by coupling an optical particle counter and a scanning mobility particle sizer. Two chemical assays were used to characterize OP of water-soluble PM2.5: dithiothreitol (DTT) and electron spin resonance (ESR) assay. OP-DTT was carried out through assessment of the capability of redox active compounds in PM2.5 to transfer electrons from DTT to oxygen thereby generating superoxides. The consumption of DTT over specific time intervals (5, 15, 25, 35 and 45 mins) was interpreted as a measure of the capability of ambient PM2.5 to produce ROS. On the other hand, OP-ESR was performed using ESR with a spin trap (5,5 – dimethylpyrroline – N – oxide or DMPO) which measures the capability of PM2.5 to generate hydroxyl radicals (•OH) though Fenton type reactions with the presence of hydrogen peroxide. Dithiothreitol (DTT) assay was used to characterize OP of water – soluble PM2.5. Varying physical and chemical properties; and OP results with biomass types and combustion conditions will be presented.