Associations between fine particulate matter and colorectal cancer: a systematic review and meta-analysis

Pengfei Fu, Ruijin Li, Stephen Cho Wing Sze*, Ken Kin Lam Yung*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review


Colorectal cancer (CRC) is the second deadliest cancer worldwide. The impact of fine particulate matter (PM2.5) on many diseases is a global concern, yet its association with CRC is unclear. This study aimed to assess the effect of PM2.5 exposure on CRC. We searched PubMed, Web of Science, and Google Scholar databases for population-based articles published before September 2022, providing risk estimates with 95% confidence intervals (CI). Among 85,743 articles, we identified 10 eligible studies across multiple countries and regions in North America and Asia. We calculated the overall risk, incidence and mortality and performed subgroup analyses according to countries and regions. The results revealed an association between PM2.5 and increased risk of CRC (total risk, 1.19 [95% CI 1.12–1.28]; incidence, OR=1.18 [95% CI 1.09–1.28]; mortality, OR=1.21 [95% CI 1.09–1.35]). The elevated risks of CRC associated with PM2.5 were different across countries and regions, at 1.34 [95% CI 1.20–1.49], 1.00 [95% CI 1.00–1.00], 1.08 [95% CI 1.06–1.10], 1.18 [95% CI 1.07–1.29], 1.01 [95% CI 0.79–1.30], in the United States, China, Taiwan, Thailand, and Hong Kong, respectively. Incidence and mortality risks were higher in North America than those in Asia. In particular, the incidence and mortality were highest in the United States (1.61 [95% CI 1.38–1.89] and 1.29 [95% CI 1.17–1.42], respectively) than those in other countries. This study is the first comprehensive meta-analysis to find a strong association between PM2.5 exposure and increased CRC risk.

Original languageEnglish
JournalReviews on Environmental Health
Publication statusE-pub ahead of print - 22 Feb 2023

Scopus Subject Areas

  • Health(social science)
  • Pollution
  • Public Health, Environmental and Occupational Health

User-Defined Keywords

  • air pollution
  • colorectal cancer
  • meta-analysis
  • PM2.5


Dive into the research topics of 'Associations between fine particulate matter and colorectal cancer: a systematic review and meta-analysis'. Together they form a unique fingerprint.

Cite this