Ambient air pollution and urological cancer risk: A systematic review and meta-analysis of epidemiological evidence

Exposure to ambient air pollution has significant adverse health effects; however, whether air pollution is associated with urological cancer is largely unknown. We conduct a systematic review and meta-analysis with epidemiological studies, showing that a 5 μg/m 3 increase in PM 2.5 exposure is associated with a 6%, 7%, and 9%, increased risk of overall urological, bladder, and kidney cancer, respectively; and a 10 μg/m 3 increase in NO 2 is linked to a 3%, 4%, and 4% higher risk of overall urological, bladder, and prostate cancer, respectively. Were these associations to reflect causal relationships, lowering PM 2.5 levels to 5.8 μg/m 3 could reduce the age-standardized rate of urological cancer by 1.5 ~ 27/100,000 across the 15 countries with the highest PM 2.5 level from the top 30 countries with the highest urological cancer burden. Implementing global health policies that can improve air quality could potentially reduce the risk of urologic cancer and alleviate its burden. Whether air pollufion is associated with urological cancer is largely unknown. In this study, the authors reveal correlafions between air pollufion and urological cancer risk: an increase of 5 μg/m 3 in PM 2.5 and 10 μg/m 3 in NO 2 would raise risks by 6-9% and 3-4%, respecfively; while lowering PM 2.5 to 5.8 μg/m 3 may reduce urological cancer burden.