Greenness, air pollution, and mortality risk: a retrospective cohort study of patients with lung cancer in China.

ABSTRACT

The association between long-term exposure to air pollution and mortality from lung cancer has been established, yet evaluations of the potential mitigating effects of greenness on this impact are scarce. We conducted a cohort study in Pingyi County. A two-level Cox proportional hazards regression model was used to examine the associations among long-term exposure to air pollution, residential greenness, and lung cancer mortality. Among the examined pollutants, nitrogen dioxide exhibited the most significant adverse effects and highest risk of lung cancer mortality, with hazard ratio (HR) = 2.783 (95% confidence interval [CI] 1.885-4.107) for all-cause mortality, HR = 2.492 (95%CI 1.659-3.741) for tumour-related mortality, and HR = 2.431 (95%CI 1.606-3.678) for lung cancer mortality. Higher greenness values were associated with a reduced risk of lung cancer mortality. These findings suggest the importance of implementing strategies for increasing greenness to reduce the health impacts of air pollution.