Ambient particulate matter exposure and urologic cancer: a longitudinal nationwide cohort study

Increased particulate matter (PM) exposure is positively associated with increased incidence and mortality of many human malignancies. However, evidence of urologic cancer is limited. We aimed to evaluate the association between PM₁₀ exposure and the relative risk of urologic cancer. This nationwide longitudinal cohort study included 231,997 participants who underwent a baseline health examination in 2008 from the National Health Information Database of Korea. The primary endpoint was newly diagnosed urologic cancer according to PM₁₀ exposure. Of the total 231,99 participants, 50,677 developed urologic cancer during a median follow-up of 6.7 years. After controlling for confounding factors, participants in the high PM₁₀ exposure group had a higher risk of kidney cancer (hazard ratio [HR] 1.111, 95% confidence interval [CI] 1.068-1.157) and prostate cancer (HR 1.083, 95% CI 1.058-1.109) than those in the low PM₁₀ exposure group. However, in urothelial cell carcinoma, there was no significant increase in the HRs in the high PM₁₀ exposure group. For kidney cancer, participants with the following characteristics were more susceptible: age < 65 years, female sex, decreased regular physical activity, current smoking, no diabetes, no hypertension, normal body mass index, and desirable total cholesterol level. For prostate cancer, participants with the following characteristics were more susceptible: decreased regular physical activity, current smoking, and no hypertension. High PM₁₀ exposure is associated with an increased risk of overall urologic cancers, especially kidney and prostate cancer.