Yes. I agree with what has also been said from London. It would be unethical to do studies where kids would be exposed and others would not.
On the other hand, I think we could have a systematic recording by groups of pediatricians on the conditions of exposure of a child--for example, with the baby monitors--and try to follow up on which kids have even minor health problems, whether it is the ones who were sleeping close to such a monitor or not.
It is observational studies that could give some idea of short-term effects. The issue of schools, again, can be addressed in part by observational study, as you described. I know I will be told that this is an exceedingly weak design for a study, but, for example, there could be an experimental design with schools being assigned as having or not having Wi-Fi. If one really wanted to have--