With mere days left for the public to comment on whether Arizona should renew air-quality permits for three uranium mines near the Grand Canyon, multiple tests found that the amount of uranium dust in soil near one of the mines is four times higher than background levels. Energy Fuels Incorporated, which operates the three mines - Pinenut, EZ, and Canyon - in Northern Arizona, reported heightened radioactivity near the Pinenut Mine in late December after routine tests revealed the level of radioactive dust had spiked.