After that, he said, it has no benefit, but has been linked to diseases such as cancer and osteoporosis.``We are not doctors; we are water providers,'' he said. ``By not putting it in, we may not be doing any good to the kids, but we are definitely not doing any harm to any of our customers.''Besides, Janet Lail added, ``If it is so good and necessary, why is it not one of the things you have to put