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Long-term exposure to ambient fine particulate matter and liver enzymes in adults: a cross-sectional study in Taiwan
  1. Zilong Zhang1,
  2. Cui Guo1,
  3. Ly-yun Chang2,
  4. Yacong Bo1,
  5. Changqing Lin3,
  6. Tony Tam4,
  7. Gerard Hoek5,
  8. Martin CS Wong1,
  9. Ta-Chien Chan6,
  10. Alexis KH Lau7,
  11. Xiang Qian Lao1
  1. 1 Jockey Club School of Public Health and Primary Care, Chinese University of Hong Kong, New Territories, Hong Kong
  2. 2 Institute of Sociology, Academia Sinica, Taipei, Taiwan
  3. 3 Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong
  4. 4 Department of Sociology, Chinese University of Hong Kong, New Territories, Hong Kong
  5. 5 Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
  6. 6 Research Center for Humanities and Social Sciences, Academia Sinica, Taipei, Taiwan
  7. 7 Division of Environment, Hong Kong University of Science and Technology, Kowloon, Hong Kong
  1. Correspondence to Dr Xiang Qian Lao, School of Public Health, The Chinese University of Hong Kong, Hong Kong; xqlao{at}


Objectives Animal experiments indicate that exposure to particulate matter (PM) can induce hepatotoxic effects but epidemiological evidence is scarce. We aimed to investigate the associations between long-term exposure to PM air pollution and liver enzymes, which are biomarkers widely used for liver function assessment.

Methods A cross-sectional analysis was performed among 351 852 adult participants (mean age: 40.1 years) who participated in a standard medical screening programme in Taiwan. Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transferase (GGT) levels were measured. A satellite-based spatio-temporal model was used to estimate the concentrations of ambient fine particles (PM with an aerodynamic diameter ≤2.5 µm, PM2.5) at each participant’s address. Linear and logistic regression models were used to investigate the associations between PM2.5 and the liver enzymes with adjustment for a wide range of potential confounders.

Results After adjustment for confounders, every 10 µg/m3 increment in 2-year average PM2.5 concentration was associated with 0.02%(95% CI: −0.04% to 0.08%), 0.61% (95% CI: 0.51% to 0.70%) and 1.60% (95% CI: 1.50% to 1.70%) increases in AST, ALT and GGT levels, respectively. Consistently, the odds ratios of having elevated liver enzymes (>40 IU/L) per 10 µg/m3 PM2.5 increment were 1.06 (95% CI: 1.04 to 1.09), 1.09 (95% CI: 1.07 to 1.10) and 1.09 (95% CI: 1.07 to 1.11) for AST, ALT and GGT, respectively.

Conclusions Long-term exposure to PM2.5 was associated with increased levels of liver enzymes, especially ALT and GGT. More studies are needed to confirm our findings and to elucidate the underlying mechanisms.

  • fine particulate matter
  • liver enzyme
  • epidemiology

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  • Contributors XQL conceived the study. LC, AKL and XQL designed the research and acquired the data. ZZ conducted statistical analysis. ZZ, GH and XQL interpreted the results. ZZ and XQL drafted the manuscript. All authors made critical revisions of the manuscript.

  • Funding This study was partially supported by Environmental Health Research Fund of the Chinese University of Hong Kong (7104946). Cui Guo and Yacong Bo are supported by the PhD Studentship of the Chinese University of Hong Kong.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent for publication Not required.