Long term exposure to air pollution and kidney parenchyma cancer - Effects of low-level air pollution: a Study in Europe (ELAPSE).

Background: Particulate matter (PM) is classified as a group 1 human carcinogen. Previous experimental studies suggest that particles in diesel exhaust induce oxidative stress, inflammation and DNA damage in kidney cells, but the evidence from population studies linking air pollution to kidney cancer is limited.

Methods: We pooled six European cohorts (N = 302,493) to assess the association of residential exposure to fine particles (PM), nitrogen dioxide (NO), black carbon (BC), warm season ozone (O) and eight elemental components of PM (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) with cancer of the kidney parenchyma. The main exposure model was developed for year 2010. We defined kidney parenchyma cancer according to the International Classification of Diseases 9th and 10th Revision codes 189.0 and C64. We applied Cox proportional hazards models adjusting for potential confounders at the individual and area-level.

Results: The participants were followed from baseline (1985-2005) to 2011-2015. A total of 847 cases occurred during 5,497,514 person-years of follow-up (average 18.2 years). Median (5-95%) exposure levels of NO, PM, BC and O were 24.1 μg/m (12.8-39.2), 15.3 μg/m (8.6-19.2), 1.6 10 m (0.7-2.1), and 87.0 μg/m (70.3-97.4), respectively. The results of the fully adjusted linear analyses showed a hazard ratio (HR) of 1.03 (95% confidence interval [CI]: 0.92, 1.15) per 10 μg/m³ NO, 1.04 (95% CI: 0.88, 1.21) per 5 μg/m³ PM, 0.99 (95% CI: 0.89, 1.11) per 0.5 10 m BCE, and 0.88 (95% CI: 0.76, 1.02) per 10 μg/m³ O. We did not find associations between any of the elemental components of PM and cancer of the kidney parenchyma.

Conclusion: We did not observe an association between long-term ambient air pollution exposure and incidence of kidney parenchyma cancer.