Long-Term Air Pollutant Exposure and the Risk of Cardiovascular- and Cancer-Related Mortality: A Prospective Cohort Study in Taiwan

Abstract

Air pollution exposure can cause vascular dysfunction and induce mutagenesis; however, its effects on cardiovascular disease (CVD)– and cancer-related mortality remain unclear. This prospective cohort study examined the impact of long-term exposure to multiple air pollutants on the risks of CVD- and cancer-related mortality among Taiwanese adults. From 2005 to 2017, we prospectively enrolled 83,257 adults who maintained the same residential address. Over a mean follow-up period of 10.6 years, participants were monitored for CVD- and cancer-related mortality. Air pollutant concentrations at each participant’s residence were estimated using an Ordinary Kriging model. The Fine–Gray subdistribution hazard model was applied to evaluate the associations between air pollutant exposure and mortality risks, treating deaths from non-CVD and non-cancer causes as competing events. During 879,834 person-years of follow-up, 2,554 participants died, including 485 (19.0%) from CVD and 1,230 (48.2%) from cancer. Time-dependent Cox proportional hazards models showed that SO₂ exposure was associated with the highest adjusted hazard ratio (aHR) for CVD-related mortality (aHR 1.23; 95% confidence interval [CI] 1.07–1.41 per 2-ppb increase), followed by PM₂.₅ (aHR 1.05; 95% CI 1.03–1.08) and PM₁₀ (aHR 1.02; 95% CI 1.01–1.04). Similar associations were observed for cancer-related mortality, with aHRs of 1.23 (95% CI 1.07–1.41) for SO₂, 1.05 (95% CI 1.03–1.08) for PM₂.₅, and 1.02 (95% CI 1.01–1.04) for PM₁₀. Long-term exposure to NO₂ and O₃ was not significantly associated with either CVD- or cancer-related mortality. These findings underscore the urgent need for effective air pollution control strategies to reduce CVD- and cancer-related mortality.