Diurnal dithiothreitol assays for biomass burning source in PM1.0 and PM2.5 during summer and winter

This study is to investigate the physicochemical characteristics of airborne particulate matter (PM) based on particle size and assess the associated human health risks. Specifically, PM was divided into PM1.0 and PM2.5 fractions, and their chemical compositions were analyzed to understand the factors influencing the difference in mass concentration between these fractions. To measure PM1.0 and PM2.5, a couple of impactor-cut type beta-ray monitors and two digital high-volume samplers were used to collect both PM1.0 and PM2.5 simultaneously collected every 6 h during summer (August 11, 2022 to August 30, 2022) and winter (November 21, 2022 to December 11, 2022) periods. The study found that PM1.0 accounts for approximately 75–85% of PM2.5 and is affected by factors such as biomass burning. Analysis of the concentration of dithiothreitol Assays showed that most of the harmful substances in PM2.5 are present in PM1.0. Furthermore, the dithiothreitol assays was found to be highly correlated with organic carbon, with significant contributions from the biomass burning source including water-soluble carbon component levoglucosan. Overall, the study provides insights into the physicochemical characteristics and human health risks associated with PM1.0 & PM2.5 and highlights the importance of considering PM1.0 in the creation and regulation of PM2.5 standards.