Diurnal Trend and Interconnections of Organic Aerosols and Volatile Chemical Products (VCPs) in a Residential Area

KYLE MCCARY, Sining Niu, Alana Dodero, Yeaseul Kim, Sahir Gagan, Timothy Onasch, Karsten Baumann, Raghu Betha, Qi Ying, Yue Zhang, Texas A&M University

     Abstract Number: 270
     Working Group: Aerosol Chemistry

Abstract
Residential areas are an important source of organic aerosols in urban environments. Exposure to high concentrations of these aerosols in residential areas can contribute to adverse respiratory health effects among local citizens. The emission of organic aerosols from residential areas can be influenced by local gas emissions, leading to further deterioration of air quality. For instance, the increasing concentration of volatile chemical products in urban environments can lead to the production of tropospheric ozone and further oxidation of organic aerosols. This study aims to analyze the emission of organic aerosols in residential areas and their interactions with gas species by combining field data with box modeling. The study specifically focuses on deriving the diurnal trend and interconnections of aerosol particles and VCPs sampled in Cane Island, Katy, Texas, within the Greater Houston Area.

The Texas A&M mobile lab was used for continuous sampling of the ambient gas and particle phase species. The lab was equipped with a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a Vocus 2R chemical ionization mass spectrometer (CIMS), an aethalometer, and O_3, CO, CO_2, and CH₄ analyzers. Additionally, temperature and relative humidity (RH) were continuously measured. Positive matrix factorization was used to distinguish local aerosol and gas species. Major VCP tracers, such as D5 and D4-siloxane, monoterpenes, texanol, p-dichlorobenzene, and parachlorobenzotrifluoride were used to estimate the local ozone contribution and their impacts on organic mass concentrations. Statistical analysis was performed using the NumPy and pandas Python packages to gain insights into the interactions between VCP and organic aerosols. This study provides a general overview of aerosol and VCP concentrations and how they vary over a daily timeframe in residential areas. Furthermore, the findings demonstrate that the emissions of organic aerosols and VCPs in residential areas can jointly interact and contribute to the local air quality.