Characterization of organic aerosols in PM1 and their cytotoxicity in an urban roadside area in Hong Kong

Xinyi Niu, Yichen Wang, Steven Sai Hang Ho, Hsiao Chi Chuang, Jian Sun, Linli Qu, Gehui Wang, Kin Fai Ho

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Organic compounds in fine particles play major roles in cardiopulmonary diseases. A study was conducted to determine the characteristics and cytotoxicity of organic aerosols (OA) in an urban roadside area in Hong Kong. Chemical components in nonrefractory submicron aerosol (NR-PM1) were observed using a Quadrupole Aerosol Chemical Speciation Monitor (Q-ACSM), and the chemical profile of organic compounds in NR-PM1 was examined with filter-based approach. Associations between cytotoxicity and organic sources and compositions were evaluated. NR-PM1 contributed to 84% of the PM1 concentrations. The NR-PM1 was composed of organics (55 ± 15%), followed by sulfate (21 ± 9%), ammonium (13 ± 6%), nitrate (10 ± 6%) and chloride (1 ± 1%). Three major organic sources were identified using positive matrix factorization, namely primary organic aerosol (POA, 40 ± 19%), more-oxidized oxygenated OA (MO-OOA, 32 ± 22%) and less-oxidized oxygenated OA (LO-OOA, 28 ± 19%). Variations in organic groups, including alkanes, hopanes, steranes, polycyclic aromatic hydrocarbons (PAHs), oxy-PAHs (OPAHs), and fatty acids, demonstrated that traffic and cooking emissions were dominant pollution sources in this roadside station. Human lung alveolar epithelial (A549) cells were exposed to PM1, revealing increases in lactate dehydrogenase (LDH), reactive oxygen species (ROS), and interlukin-6 (IL-6), which indicated the occurrence of inflammatory and oxidative responses. POA was significantly associated with ROS and IL-6, and alkanes, hopanes, steranes, PAHs and OPAHs, and fatty acids presented medium to high correlations with LDH and IL-6, demonstrating the importance of primary emissions and organic compounds in cytotoxicity. This study demonstrated that organic compounds emitted from traffic and cooking play critical roles in PM-induced oxidative stress and inflammation in urban areas.

Original languageEnglish
Article number128239
Publication statusPublished - Jan 2021


  • Aerosol chemical speciation monitor
  • Inflammation
  • Organic compounds
  • Oxidative stress

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Chemistry(all)
  • Pollution
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'Characterization of organic aerosols in PM1 and their cytotoxicity in an urban roadside area in Hong Kong'. Together they form a unique fingerprint.

Cite this