jon: alex, thank you. for years the u.s. military used burn pits to incinerate all trash, including plastics and medical waste before leaving a particular scene. exposure to the smoke can have lasting effects on those who are exposed. jennifer givein takes a look at that. the first time i saw the burn pits, it was minds boggling. i couldn t understand why we were burning trash. army veteran sedoe was stationed in tikrit, iraq. like many other bases, everything from plastic bottles to medical waste was thrown into