AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Oxidative Potential and Chemical Characteristics of Water-soluble PM2.5 Collected from Various Sites in South Korea
LUCILLE JOANNA BORLAZA, Minhan Park, KwangYul Lee, HungSoo Joo, Tsatsral Batmunkh, Kihong Park, Gwangju Institute of Science and Technology
Abstract Number: 260 Working Group: Health Related Aerosols
Abstract Substantial research has confirmed that health effects of fine particulate matter (PM2.5) can be attributed to several other factors other than just PM2.5 mass levels. A large number of these studies have pointed to redox active compounds of PM2.5 as a culprit, hence the growing interest on oxidative potential (OP) of PM2.5 as a more suitable health-based measure. The OP analysis can assess the capability of PM2.5 to produce reactive oxygen species (ROS) which is suggested that at exceeding normal range have considerable implications. This study looked into OP and its association with chemical composition of ambient PM2.5 collected from various sites in South Korea. Ambient PM2.5 was collected on zeflour and quartz filters using URG cyclones at several sites (urban, industrial, road side, and rural sites). Chemical analysis for inorganic ions, metals, organic carbon (OC) and elemental carbon (EC) were done. 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. Results for all chemical and OP analyses will be presented in this study.