People used to bury stuff in their gardens, e.g. Plastic & Asbestos. Imagine you bury it on a hill and a bit further down, say, 20 meters, they have a little garden with radishes and onions and potatoes and stuff and in a little greenhouse in between there are tomatoes growing. Insects are crawling all over the place and micey beings are doing their thing. There's cats and birds and stuff is happening. And it gets warmer every year and the kids and grandkids are playing and building and burning things and they love the fruits and vegetables coming out of and around this garden. Multiply this by a neighborhood. And remember, 60, 70 years ago, lefties, hippies and scientists have put effort into warning people.