The PM_2.5 concentration reduction improves survival rate of lung cancer in Beijing

Introduction: Long-term exposure to ambient fine particulate matter (PM_2.5) has been linked to increases in the incidence of lung cancer. However, more evidence is needed to conclude its effects on lung cancer survival.

Objectives: The study aimed to explore the relationship between long-term PM_2.5 exposure and lung cancer survival and evaluated the benefits of clean air actions in Beijing.

Methods: A whole-population cohort study was conducted on lung cancer patients diagnosed between 2001 and 2017. An atmospheric chemical transport model was used to estimate exposure under a counterfactual scenario without the policy and then quantified the effect of the policy. Cox regression models were used with the seasonality-adjusted PM_2.5 as the main effect.

Results: A 10 μg/m³ increase in PM_2.5 was estimated to be with a 6.5 % (95 % CI: 4.8 %, 8.2 %) increase in the mortality rates. The association was heterogeneous and modified by individual-level characteristics. The clean air actions were estimated to have prevented 3548 (95 % CI: 3280, 3825) premature deaths and to have prolonged survival time by 4.29 months (95 % CI: 0.01, 25.11).

Conclusion: Our findings suggest that PM_2.5 exposure lowers the survival rate for lung cancer. The clean air actions implemented in Beijing can protect lung cancer patients by increasing their survival time.

Synopsis: Long-term exposure to PM_2.5 can lower lung patients' survival rates whereas the clean air actions in Beijing have prolonged these patients' survival time by reducing PM_2.5 level.