Fine and ultrafine particles in Taiwan urban area
Journal
AIP Conference Proceedings
Journal Volume
2447
Date Issued
2021
Author(s)
Hsiao T.-C.
Abstract
In urban areas, traffic emission is a growing concern for ambient air quality and public health. Ultrafine particles (UFP) and black carbon (BC), a fraction of ambient particulate matter (PM), are both closely related to traffic emissions. Characterizing their physical and chemical properties is a crucial step in assessing health effects and air pollution policies. This study set up a traffic-influenced site in Taipei urban area to continuously measure different aerosol properties of PM2.5 and PM1.0. The particle size distributions (PSD) have shown that the geometric mean diameter (GMD) and the total particle number concentration (PNC) of UFPs displayed an opposite diurnal variation and were strongly affected by traffic flux. In addition, the ratio of surface area concentrations directly measured by Nanoparticle Surface Area Monitor (NSAM, TSI 3550) and estimated by the measurements using Scanning Mobility Particle Sizer (SMPS, TSI 3938) is proposed as a new indicator to quantify the irregular morphology of UFPs. It was found that the ratio is well correlated with BC and exhibits peaks in daily rush hour, suggesting that most BC have a non- spherical shape in the urban environment. ? 2021 Author(s).
Type
conference paper