"isn't their an app for that? (simply plug in wattage, freq, etc. and read out safe distance?)"
Yes, there are several available for free on the Internet. Some are "on-line" calculators and some are programs that you can download and install on your computer. One downloadable is called "RF Safety Calculator".
that was easy, thanks
=> http://hintlink.com/power_density.php
Unfortunately, that site has at least one serious error which brings its results into question. It says to enter a gain of 2.2 dB for a dipole. That would only be true if the dipole was in free space. Most back yard dipoles will have > 6 dBi of gain or put another way, more than 4 dBd of gain.
- Glenn W9IQ
If you check the box that says "Do you wish to include effects of ground reflections?" it adds about 4 dB to the basic calculation. I have no idea if that's correct or not.