Nitrogen dioxide exposure and lung cancer risk in non-European countries: a systematic review and meta-analysis of the decades 2014-2024
A partir d'une revue systématique de la littérature publiée jusqu'en juin 2024 (11 études, 68 367 056 personnes), cette méta-analyse évalue l'association entre une exposition au dioxyde d'azote et le risque de cancer du poumon, en dehors de l’Europe
Background: Lung cancer remains a leading cause of incidence and mortality worldwide, with nitrogen dioxide (NO2) as a potential risk factor. While European studies have shown a positive association between NO2 exposure and lung cancer risk, evidence from non-European regions is limited.
Methodology: This systematic review and meta-analysis of 11 cohort studies comprising 68,367,056 participants, identified from Google Scholar, PubMed, and Science Direct up to June 6, 2024, was performed to evaluate the impact of NO2 on the risk of lung cancer beyond Europe. Studies were selected on the basis of predefined criteria, and the risk of bias was assessed via the Newcastle-Ottawa Scale (NOS). Hazard ratios (HRs) were standardized to 10 parts per billion (ppb) increase in NO2.
Results: The pooled HR represents the change in lung cancer risk per 10 ppb increase in NO2 exposure. Overall, NO2 exposure was significantly associated with increased lung cancer risk (pooled HR: 1.08, 95% CI: 1.03-1.13). Subgroup analyses revealed significant associations with lung cancer incidence (HR: 1.06, 95% CI: 1.01-1.12) and mortality (HR: 1.13, 95% CI: 1.01-1.26). Smoking-specific analyses were not statistically significant among smokers (HR = 1.06; 95% CI: 0.98-1.15) or non-smokers (HR = 0.96; 95% CI: 0.86-1.08). Regional variations included significant associations in America (HR: 1.06, 95% CI: 1.02-1.11) but not in Asia (HR: 1.22, 95% CI: 0.96-1.55). Limitations include evidence gaps between low-income countries and regional differences.
Conclusion: In summary, this meta-analysis suggests that NO2 exposure is associated with an increased risk of lung cancer beyond European countries. This study highlights the need for global air quality regulations and further research into the role of NO2 in lung cancer.
BMC Cancer , article en libre accès, 2026