Abstract. Vehicle exhaust and cooking emissions are closely related to the daily life
of city dwellers. Here, we defined the secondary organic aerosols (SOAs)
derived from vehicle exhaust and cooking emissions as “urban-lifestyle SOAs”
and simulated their formation using a Gothenburg potential aerosol mass
reactor (Go:PAM). The vehicle exhaust and cooking emissions were separately
simulated, and their samples were defined as “vehicle group” and “cooking
group”, respectively. After samples had been aged under 0.3–5.5 d of
equivalent photochemical age, these two urban-lifestyle SOAs showed markedly
distinct features in the SOA mass growth potential, oxidation pathways, and
mass spectra. The SOA/POA (primary organic aerosol) mass ratios of vehicle
groups (107) were 44 times larger than those of cooking groups (2.38) at
about 2 d of equivalent photochemical age, according to the measurement
of scanning mobility particle sizer (SMPS). A high-resolution time-of-flight
aerosol mass spectrometer was used to perform a deeper analysis. It revealed
that organics from the vehicle may undergo the alcohol and/or peroxide and
carboxylic acid oxidation pathway to produce abundant less and more oxidized
oxygenated OAs (LO-OOAs and MO-OOAs), and only a few primary hydrocarbon-like
organic aerosols (HOAs) remain unaged. In contrast, organics from cooking may
undergo the alcohol and/or peroxide oxidation pathway to produce moderate LO-OOAs,
and comparable primary cooking organic aerosols (COAs) remain unaged. Our
findings provide an insight into atmospheric contributions and chemical
evolutions for urban-lifestyle SOAs, which could greatly influence the air
quality and health risk assessments in urban areas.
Secondary organic aerosols produced from photochemical oxidation of secondarily evaporated biomass burning organic gases: Chemical composition, toxicity, optical properties, and climate effect
