Atmospheric Chemistry and Physics | 2021
Formation and evolution of secondary organic aerosols derived from urban-lifestyle sources: vehicle exhaust and cooking emissions
Abstract
Abstract. Vehicle exhaust and cooking emissions are closely related to the daily life\nof city dwellers. Here, we defined the secondary organic aerosols (SOAs)\nderived from vehicle exhaust and cooking emissions as “urban-lifestyle SOAs”\nand simulated their formation using a Gothenburg potential aerosol mass\nreactor (Go:PAM). The vehicle exhaust and cooking emissions were separately\nsimulated, and their samples were defined as “vehicle group” and “cooking\ngroup”, respectively. After samples had been aged under 0.3–5.5\u2009d of\nequivalent photochemical age, these two urban-lifestyle SOAs showed markedly\ndistinct features in the SOA mass growth potential, oxidation pathways, and\nmass spectra. The SOA/POA (primary organic aerosol) mass ratios of vehicle\ngroups (107) were 44 times larger than those of cooking groups (2.38) at\nabout 2\u2009d of equivalent photochemical age, according to the measurement\nof scanning mobility particle sizer (SMPS). A high-resolution time-of-flight\naerosol mass spectrometer was used to perform a deeper analysis. It revealed\nthat organics from the vehicle may undergo the alcohol and/or peroxide and\ncarboxylic acid oxidation pathway to produce abundant less and more oxidized\noxygenated OAs (LO-OOAs and MO-OOAs), and only a few primary hydrocarbon-like\norganic aerosols (HOAs) remain unaged. In contrast, organics from cooking may\nundergo the alcohol and/or peroxide oxidation pathway to produce moderate LO-OOAs,\nand comparable primary cooking organic aerosols (COAs) remain unaged. Our\nfindings provide an insight into atmospheric contributions and chemical\nevolutions for urban-lifestyle SOAs, which could greatly influence the air\nquality and health risk assessments in urban areas.\n