Turner MC, et al. - In the large-scale Spanish Bladder Cancer Study, researchers examined associations of ambient air pollution and bladder cancer risk. They assigned estimates of ambient fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) concentrations to the geocoded participant residence of 938 incident bladder cancer cases and 973 hospital controls based on European multi-city land-use regression models. Outcomes revealed no clear association between either ambient PM_2.5 or NO₂ concentrations and incident bladder cancer risk. Results among more residentially stable participants and in two-pollutant models were also similar.