Hi! I pulled up the really old carpet in a small room/office that I'll be converting to a school room and found a red stain color covering the entire floor. At first I thought someone had purposefully stained it that color, but then when some water got spilled on it and I wiped it up, some of the red color was on my towel. Does anyone know what else that could be? I'm a little nervous that it could be lead based and because I have young kids, I don't want to be tracking it around my house. Thanks!