Nature World: Wildfires are putting more and more Americans at risk, and not just those in the path of the blaze. In 2011, more than 200 million were affected by harmful wildfire smoke as it drifted across state and county lines, the Natural Resources Defense Council (NRDC) warns in a new report entitled "Where There's Fire, There's Smoke."
The study determined that the area affected by smoke is roughly 50 times greater than the area burned by fire, with about two-thirds of Americans affected in 2011, one of...