TPS 682: Long-term health effects of air pollutants 2, Exhibition Hall, Ground floor, August 27, 2019, 3:00 PM - 4:30 PM
Background: Moderate correlations were previously observed between individual estimates of traffic-related air pollution (TRAP) produced by different exposure modeling approaches. This may imply an exposure misclassification for a substantial fraction of subjects, which may result in an underestimation of the true association between TRAP and health outcomes in epidemiological studies.
Aim: We integrated individual estimates produced by well-established modeling approaches to reevaluate the association with cancers previously linked to TRAP (lung, breast and prostate), other cancers, and all-cause mortality in a cohort of coronary patients.
Methods: Patients undergoing percutaneous coronary interventions in a major Israeli medical center from 2004-2014 (n=10,627) were followed for cancer and mortality through national registries. Residential exposure to nitrogen oxides (NOx) was estimated by optimized dispersion model (ODM) and land use regression (LUR) (rPearson=0.50). Mutually exclusive groups of subjects classified as exposed by none of the methods, ODM alone, LUR alone, or both methods were created. Associations were examined using Cox regression models.
Results: During follow-up, 741 incident cancer cases were diagnosed (median, 7 years) and 3,051 deaths occurred (median, 9 years). Using a ≥25 ppb cutoff, the multivariable-adjusted hazard ratios (95% confidence intervals) for lung, breast and prostate cancer were 1.56 (1.13-2.15) in doubly exposed, 1.27 (0.86-1.86) in LUR alone, and 1.13 (0.77-1.65) in ODM alone, compared with doubly unexposed subjects. The association of the former category was strengthened using more extreme NOx cutoffs: 1.62 (1.16-2.25), 1.72 (1.21-2.45), and 1.83 (1.26-2.67) for ≥26, ≥27, and ≥28 ppb, respectively. A similar pattern, albeit less strong, was observed for mortality, whereas no association was shown for cancers not previously linked to TRAP.
Conclusions: Integrating TRAP exposure estimates results in a more robust association with outcomes. This novel approach should be further examined in future studies.