Teetawat Santijitpakdee. Health risk assessment by oxidative potential measurement of ambient PM2.5: a study in Chiang Mai city. Master's Degree(Health Sciences Research). Chiang Mai University. Library. : Chiang Mai University, 2024.
Health risk assessment by oxidative potential measurement of ambient PM2.5: a study in Chiang Mai city
Abstract:
To investigate the oxidative potential (OP) of fine particulate matter (PM2.5) and its chemical components, a dithiothreitol assay (DTT) was used to analyze the OP of 89 samples of PM2.5 filters collected between January and December 2021 in Chiang Mai City (CM), Northern Thailand. We analyzed chemical components bound on PM2.5, including carbonaceous components [i.e., water-soluble organic carbon (WSOC), organic carbon (OC), elemental carbon (EC)], biogenic SOA tracers, biomass burning tracers, secondary oxidation, and lipid tracers. OPDTTv was used to implicate the health risks from the OP of ambient PM2.5. This study introduced OPDTTv, a method to normalize oxidative potential (OP) by air volume, enabling standardized assessment of PM2.5 inhalation exposure and associated oxidative effects. It reveals a statistically significant positive correlation (r = 0.666, p-value < 0.01) between all year-round 2021 PM2.5 concentrations and OPDTTv, highlighting the increased OP with increasing PM2.5 concentrations. All the OP of PM2.5 concentrations and the OP of PM2.5 components in HBB period were higher than LBB period. Carbonaceous components and secondary oxidation components show strong correlations, indicating their significant contribution to the OP of PM2.5. Lipid tracers and biomass burning tracers exhibited a moderate correlation. Our study showed that the OPDTTv of PM2.5 provides novel analysis of PM2.5, supporting in understanding health risks of PM2.5 and informing air quality regulations for protecting public health.