It could be from the chemicals in the fabric. Also, Febreeze, scented items, perfumes, these are all made with petroleum. Not good for anyone to be breathing or absorbing through their skin, and some people display sensitivities more obviously than others. Physical problems, as well as attention, learning, mood issues can all be attributed to these chemicals, as well. We don't use scented or dyed anything at our house, and commercials for all the scented stuff to keep your laundry or home smelling "fresh" just drive me nuts- that stuff is SO bad for you (and the people around you who have to breath it, too!). Don't even get me started on all the petroleum and other chemicals that are FDA approved and added to processed food more often than not.