OrlyNorly, 802.11b/g runs on about 2.45 GHz. This isn't too far from the 1900MHz cell phone band. And they emit similar power levels.
Random folks have claimed for years that microwaves in the 1900MHz band cause various forms of cancer. Years have gone by, the issue has been extensively studied, and to my knowledge there is no scientifically rigorous study that shows causality, or even strong correlation.
The 2.45GHz band is, in my opinion, probably safer than the 1900MHz band because the energy is principally absorbed by water inside your body. That in particular would make it difficult to get standing waves going.
So I don't think you need be strongly concerned.
That said, I would strongly urge you to minimize the amount of RF that you are continuously exposed to, just in case. If you don't need 5 APs, don't have them. If you can put some on power strips or otherwise not run them all the time, that would be good too. Don't expose yourself to more RF needlessly.