Exposures to environmental pollutants and risk of cervical cancer: a systematic review and meta-analysis of observational studies

Environmental pollutants exposures have been linked to numerous adverse health outcomes, including cervical cancer. However, the evidence has been inconsistent. Therefore, this study aimed, for the first time, to systematically evaluate the relationship between exposure to environmental pollutants and cervical cancer by conducting a meta-analysis to synthesize the effect measures from previously published studies. We conducted this review in accordance with PRISMA guidelines, ensuring a comprehensive and systematic approach. Our search spanned Scopus, PubMed, and Web of Science, targeting relevant English-language articles published up to October 16, 2024. To provide a reliable analysis, we used a conservative random-effects Restricted Maximum Likelihood (REML) meta-analysis for all associations examined. The robustness of our results was tested using leave-one-out sensitivity analyses. Additionally, we assessed publication bias through Begg's test, Egger's test, funnel plots, and the trim-and-fill method. From our extensive search across multiple databases, we initially identified 2802 articles, with 11 meeting our criteria for this review, and four selected for meta-analysis. Our meta-analysis found a slight but significant increase in cervical cancer risk linked to environmental pollution, with an overall standardized incidence ratio (SIR) of 1.01 (95% CI 1.00, 1.01). There was considerable variability among the studies (I² = 80.44%). Subgroup analyses revealed a higher risk associated with ambient air pollution (SIR = 2.80, 95% CI 0.83–3.62) compared to other environmental pollutant types. These results highlight the significant impact of environmental pollutants on cervical cancer risk, underscoring the importance of standardized exposure assessments and further research in diverse populations.