Outdoor air pollution may increase the risk of chronic kidney disease and contribute to kidney failure, say researchers. Scientists culled national VA databases to evaluate the effects of air pollution and kidney disease on nearly 2.5 million people over a period of 8.5 years, beginning in 2004. The scientists compared VA data on kidney function to air-quality levels collected by the Environmental Protection Agency (EPA) as well as the National Aeronautics and Space Administration (NASA).