Highlights from Our Research Work

Greenness mitigates PM2.5-associated mortality among MDR-TB patients

In a cohort of 2,305 individuals with MDR-TB, greater exposure to surrounding greenness was linked to reduced mortality risk following infection. Read More

Pre-existing comorbidities’ association with COVID-19 mortality rate in Canada

Using population-wide data, the presence and accumulation of comorbidities were found to dramatically raise mortality and severity risks from COVID-19, especially in older adults and younger individuals with five or more conditions. Read More

Southern Ontario’s Higher Ozone Levels Linked to Spatial and Seasonal Trends (2004–2023)

A high-resolution machine-learning model revealed that elevated surface ozone levels in southern Ontario—though decreasing in summer—persistently exceeded WHO guidelines comparing to northern Ontario. Read More

Longer Travel Times Limit Hospital Access in Northern Ontario Despite Higher Per-Capita Capacity

Spatial modelling showed that northern Ontario residents face significantly longer travel times and poorer access to hospital care compared to southern regions, even though northern hospitals provide relatively greater capacity per capita. Read more

Key Publications (Latest Five Years)

Environment & Health

  • Duan, X., Zhao, W., Yang, B., Lao, L., Mei, Y., Wu, C., Liao, Y., Wang, Y., Feng, Z., Chen, W., Ge, E., Deng, H., & Liu, X. (2024). Association of residential greenness with obstructive sleep apnea among Chinese older adults and the mediation role of PM₂.₅ and leisure-time physical activity. Science of the Total Environment, 915, Article 170120. https://doi.org/10.1016/j.scitotenv.2024.170120
  • Feng, H., Ge, E., Grubic, N., Liu, X., Zhang, H., Sun, Q., Wei, X., Zhou, F., Huang, S., Chen, Y., Guo, H., Li, J., Zhang, K., Luo, M., & Chen, L. (2024). Coarse particulate air pollution and mortality in a multidrug-resistant tuberculosis cohort. Science of the Total Environment, 946, 174048. https://doi.org/10.1016/j.scitotenv.2024.174048
  • Ge, E., Gao, J., Wei, X., Ren, Z., Wei, J., Liu, X., Wang, X., Zhong, J., Lu, J., Tian, X., Fei, F., Chen, B., Wang, X., Peng, Y., Luo, M., & Lei, J. (2022). Effect modification of greenness on PM₂.₅-associated all-cause mortality in a multidrug-resistant tuberculosis cohort. Thorax, 77(12), 1202–1209. https://doi.org/10.1136/thoraxjnl-2020-216819
  • Ge, E., Su, M., Zhao, R., Huang, Z., Shan, Y., & Wei, X. (2021). Geographical disparities in access to hospital care in Ontario, Canada: A spatial coverage modelling approach. BMJ Open, 11(1), e041474. https://doi.org/10.1136/bmjopen-2020-041474
  • Ge, E., Gao, J., Ren, Z., Liu, X., Luo, M., Zhong, J., Fei, F., Chen, B., Wang, X., Wei, X., & Peng, Y. (2021). Greenness exposure and all-cause mortality during multi-drug resistant tuberculosis treatment: A population-based cohort study. Science of the Total Environment, 771, Article 145422. https://doi.org/10.1016/j.scitotenv.2021.145422
  • Ge, E., Li, Y., Wu, S., Candido, E., & Wei, X. (2021). Association of pre-existing comorbidities with mortality and disease severity among 167,500 individuals with COVID-19 in Canada: A population-based cohort study. PLOS ONE, 16(10), e0258154. https://doi.org/10.1371/journal.pone.0258154
  • Liang, S., Zhu, J., McGihon, R., Terebessy, E., Ge, E., Su, Y., Fong, I., & To, T. (2021). Visualizing and forecasting the association of air quality and health outcomes in Ontario, Canada. The Canadian Geographer, 65(2), 267–281. https://doi.org/10.1111/cag.12673
  • Tian, H., Zhou, Y., Wang, Z., Huang, X., Ge, E., Wu, S., Wang, P., Tong, X., Ran, P., & Luo, M. (2021). Effects of high-frequency temperature variabilities on the morbidity of chronic obstructive pulmonary disease: Evidence in 21 cities of Guangdong, South China. Environmental Research, 201, 111544. https://doi.org/10.1016/j.envres.2021.111544
  • Zhan, C., Xie, M., Huang, C., Liu, J., Wang, T., Xu, M., Ma, C., Yu, J., Jiao, Y., Li, M., Li, S., Zhuang, B., Zhao, M., & Nie, D. (2020). Ozone affected by a succession of four landfall typhoons in the Yangtze River Delta, China: Major processes and health impacts. Atmospheric Chemistry and Physics, 20, 13781–13799. https://doi.org/10.5194/acp-20-13781-2020
  • Zhan, C., Xie, M., Liu, J., Wang, T., Xu, M., Chen, B., Li, S., Zhuang, B., & Li, M. (2021). Surface ozone in the Yangtze River Delta, China: A synthesis of basic features, meteorological driving factors, and health impacts. Journal of Geophysical Research: Atmospheres, 126(6), e2020JD033600. https://doi.org/10.1029/2020JD033600

Exposure assessment

  • Chen, Z., Liu, J., Qie, X., Cheng, X., Yang, M., Shu, L., & Zang, Z. (2024). Stratospheric influence on surface ozone pollution in China. Nature Communications, 15(1), Article 4064. https://doi.org/10.1038/s41467-024-48406-x
  • Chen, Z., Liu, J., Qie, X., Cheng, X., Yang, M., Shu, L., & Chen, J. M. (2024). Concurrence of high dust aerosol and stratosphere-intruded ozone pollution in super sandstorms. Science Bulletin, 69(16), 2509–2513. https://doi.org/10.1016/j.scib.2024.04.046
  • Chen, Z., Liu, J., Cheng, X., Yang, M., & Shu, L. (2023). Stratospheric influences on surface ozone increase during the COVID-19 lockdown over northern China. Climate and Atmospheric Science, 6(1), 76. https://doi.org/10.1038/s41612-023-00406-2
  • Chen, Z., Liu, J., Qie, X., Cheng, X., Shen, Y., Yang, M., Jiang, R., & Liu, X. (2022). Transport of substantial stratospheric ozone to the surface by a dying typhoon and shallow convection. Atmospheric Chemistry and Physics, 22, 8221–8240. https://doi.org/10.5194/acp-22-8221-2022
  • Chen, X., Jiang, Z., Shen, Y., Li, R., Fu, Y., Liu, J., Han, H., Liao, H., Cheng, X., Jones, D. B. A., Worden, H., & Abad, G. G. (2021). Chinese regulations are working—Why is surface ozone over industrialized areas still high? Applying lessons from Northeast US air quality evolution. Geophysical Research Letters, 48(14), e2021GL092816. https://doi.org/10.1029/2021GL092816
  • Cheng, X., Liu, J., Zhao, T., Xie, X., Chen, Z., Shi, Z., Li, X., Wang, H., & Yang, M. (2023). Impact of the Tibetan Topography on Downwind Spatial Distribution of Fine Particulate Matter in Winter. Journal of Climate, 36(6), 1561–1574. https://doi.org/10.1175/JCLI-D-22-0232.1
  • Fang, K., Yao, Q., Guo, Z., Zheng, B., Du, J., Qi, F., Yan, P., Li, J., Ou, T., Liu, J., & He, M. (2021). ENSO modulates wildfire activity in China. Nature Communications, 12, Article 1764. https://doi.org/10.1038/s41467-021-21988-6
  • Shu, L., Wang, T., Li, M., Xie, M., & Liu, J. (2024). Improved ozone simulation in East Asia via assimilating observations from the first geostationary air-quality monitoring satellite. Atmospheric Environment, 319, Article 120288. https://doi.org/10.1016/j.atmosenv.2023.120288
  • Su, Y., Zhang, C., Ciais, P., Zeng, Z., Cescatti, A., Shang, J., Chen, J. M., Liu, J., Wang, Y.-P., Yuan, W., Peng, S., Lee, X., Zhu, Z., Fan, L., Liu, X., Liu, L., Lafortezza, R., Li, Y., Ren, J., Yang, X., & Chen, X. (2023). Asymmetric influence of forest cover gains and loss on land surface temperature. Nature Climate Change, 13(8), 823–831. https://doi.org/10.1038/s41558-023-01757-7
  • Wu, S., Luo, M., Wang, X., Ge, E., Zhang, W., Gu, X., & Liu, J. (2023). Season-dependent heatwave mechanisms: A study of southern China. Weather and Climate Extremes, 42, Article 100603. https://doi.org/10.1016/j.wace.2023.100603
  • Zhang, H., Luo, M., Pei, T., Liu, X., Wang, L., Zhang, W., Lin, L., Ge, E., Liu, Z., & Liao, W. (2023). Unequal urban heat burdens impede climate justice and equity goals. The Innovation, 4(5), Article 100488. https://doi.org/10.1016/j.xinn.2023.100488
  • Zang, Z., Liu, J., Ge, E., Zhang, Y. (2025). Two-decade spatiotemporal variations in ground-level ozone over Ontario, Canada. Frontiers in Environmental Engineering, 4, 1601213, https://doi.org/10.3389/fenve.2025.1601213
  • Zhang, H., Luo, M., Zhao, Y., Lin, L., Ge, E., Yang, Y., Ning, G., Cong, J., Zeng, Z., Gui, K., Li, J., Chan, T. O., Li, X., Wu, S., Wang, P., & Wang, X. (2023). HiTIC-Monthly: A monthly high spatial resolution (1 km) human thermal index collection over China during 2003–2020. Earth System Science Data, 15, 359–381. https://doi.org/10.5194/essd-15-359-2023
  • Zeng, Z., Gui, K., Wang, Z., Luo, M., Geng, H., Ge, E., An, J., Song, X., Ning, G., & Zhai, S. (2021). Estimating hourly surface PM₂.₅ concentrations across China from high-density meteorological observations by machine learning. Atmospheric Research, 254, Article 105516. https://doi.org/10.1016/j.atmosres.2021.105516
  • Li, X., Luo, M., Zhao, Y., Lin, L., Ge, E., Yang, Y., Ning, G., Zeng, Z., Cong, J., Zhang, H., Wu, S., Wang, P., & Wang, X. (2023). A daily high-resolution (1 km) human thermal index collection over the North China Plain from 2003 to 2020. Scientific Data, 10, 634. https://doi.org/10.1038/s41597-023-02535-y