Dr. John Liggio

Image John Liggio
Research Scientist - Gas and particle chemistry research: Understanding atmospheric processes leading to secondary organic chemicals

Current research and/or projects

Field and laboratory studies of primary aerosol emissions, secondary organic aerosol formation, evolution, transformation and fate; understanding the processes controlling the formation of smog

  • Process research on aerosol particle emissions and transformation in the atmosphere through laboratory and field studies
  • Ammonia/sulfuric acid/organic aerosol interactions; 
  • Black carbon emissions from gasoline and diesel vehicles
  • Kinetics of heterogeneous reactions and secondary organic aerosol formation; elucidation of new secondary organic aerosol formation mechanisms
  • Near roadway measurements of vehicle emissions and their evolution; implications for population exposure
  • Aerosol mass spectrometry and chemical mass spectrometry measurements of oxidants and aerosols.

Professional activities / interests

Collaboration with university colleagues in Canada, US, and Europe

Education and awards

Ph.D. - Department of Chemistry and Centre for Atmospheric Chemistry (York University, 2004)

International experience and/or work

WMO science advisory group - Aerosols

Key publications

1              Brook, J. R. et al. Advances in science and applications of air pollution monitoring: A case study on oil sands monitoring targeting ecosystem protection. J. Air Waste Manage. Assoc. 69, 661-709, doi:10.1080/10962247.2019.1607689 (2019).

2              Cheng, Y. et al. Top-Down Determination of Black Carbon Emissions from Oil Sand Facilities in Alberta, Canada Using Aircraft Measurements. Environ. Sci. Technol., doi:10.1021/acs.est.9b05522 (2019).

3              Cheng, Y. et al. The effects of biodiesels on semivolatile and nonvolatile particulate matter emissions from a light-duty diesel engine. Environ. Pollut. 230, 72-80, doi:10.1016/j.envpol.2017.06.014 (2017).

4              Ditto, J. C. et al. Atmospheric evolution of emissions from a boreal forest fire: The formation of highly functionalized oxygen-, nitrogen-, and sulfur-containing organic compounds. Atmos. Chem. Phys. 21, 255-267, doi:10.5194/acp-21-255-2021 (2021).

5              Lee, A. K. Y. et al. A large contribution of anthropogenic organo-nitrates to secondary organic aerosol in the Alberta oil sands. Atmos. Chem. Phys. 19, 12209-12219, doi:10.5194/acp-19-12209-2019 (2019).

6              Li, K. et al. Understanding the Impact of High-NOx Conditions on the Formation of Secondary Organic Aerosol in the Photooxidation of Oil Sand-Related Precursors. Environ. Sci. Technol. 53, 14420-14429, doi:10.1021/acs.est.9b05404 (2019).

7              Li, K., Liggio, J., Lee, P., Han, C. & Liu, Q. Secondary organic aerosol formation from α-pinene, alkanes, and oil-sands-related precursors in a new oxidation flow reactor. Atmos. Chem. Phys. 19, 9715-9731, doi:10.5194/acp-19-9715-2019 (2019).

8              Li, S. M. et al. Differences between measured and reported volatile organic compound emissions from oil sands facilities in Alberta, Canada. Proc. Natl. Acad. Sci. U.S.A. 114, E3756-E3765, doi:10.1073/pnas.1617862114 (2017).

9              Liggio, J. et al. Oil sands operations as a large source of secondary organic aerosols. NATURE 534, 91-94, doi:10.1038/nature17646 (2016).

10           Liggio, J. et al. Measured Canadian oil sands CO 2 emissions are higher than estimates made using internationally recommended methods. Nat. Commun. 10, doi:10.1038/s41467-019-09714-9 (2019).

11           Liggio, J. et al. Understanding the primary emissions and secondary formation of gaseous organic acids in the oil sands region of Alberta, Canada. Atmos. Chem. Phys. 17, 8411-8427, doi:10.5194/acp-17-8411-2017 (2017).

12           Liggio, J. et al. Quantifying the Primary Emissions and Photochemical Formation of Isocyanic Acid Downwind of Oil Sands Operations. Environ. Sci. Technol. 51, 14462-14471, doi:10.1021/acs.est.7b04346 (2017).

13           Liu, Q. et al. Oxidative and Toxicological Evolution of Engineered Nanoparticles with Atmospherically Relevant Coatings. Environ. Sci. Technol. 53, 3058-3066, doi:10.1021/acs.est.8b06879 (2019).

14           Liu, Q., Liggio, J., Li, K., Lee, P. & Li, S. M. Understanding the Impact of Relative Humidity and Coexisting Soluble Iron on the OH-Initiated Heterogeneous Oxidation of Organophosphate Flame Retardants. Environ. Sci. Technol. 53, 6794-6803, doi:10.1021/acs.est.9b01758 (2019).

15           Liu, Q. et al. Atmospheric OH Oxidation Chemistry of Particulate Liquid Crystal Monomers: An Emerging Persistent Organic Pollutant in Air. Environmental Science and Technology Letters 7, 646-652, doi:10.1021/acs.estlett.0c00447 (2020).

16           Liu, Q. et al. Experimental Study of OH-Initiated Heterogeneous Oxidation of Organophosphate Flame Retardants: Kinetics, Mechanism, and Toxicity. Environ. Sci. Technol. 53, 14398-14408, doi:10.1021/acs.est.9b05327 (2019).

17           Liu, Q. et al. Understanding the Key Role of Atmospheric Processing in Determining the Oxidative Potential of Airborne Engineered Nanoparticles. Environmental Science and Technology Letters 7, 7-13, doi:10.1021/acs.estlett.9b00700 (2020).

18           Mungall, E. L. et al. Microlayer source of oxygenated volatile organic compounds in the summertime marine Arctic boundary layer. Proc. Natl. Acad. Sci. U.S.A. 114, 6203-6208, doi:10.1073/pnas.1620571114 (2017).

19           Wren, S. N. et al. Elucidating real-world vehicle emission factors from mobile measurements over a large metropolitan region: A focus on isocyanic acid, hydrogen cyanide, and black carbon. Atmos. Chem. Phys. 18, 16979-17001, doi:10.5194/acp-18-16979-2018 (2018).

Research facility

4905 Dufferin Street
Toronto, ON M3H 5T4


WMO science advisory group - Aerosols

Adjunct Professor - Department of Chemistry, York University