Hell no.

Is it location dependent? (Duh.)

As you say. There are rocks with lots of radioactive isotopes and ones with few. In connection with that, radon (a radioactive inert gas escaping from bedrock) is produced differently in different locations, and collects up in cloed rooms if you don't ventilate. Cosmic radiation reaching you depends on altitude (hence the airplane thingy, but it also makes a difference on high mountains).

Does it change over time

Yes. Part of background radiation is cosmic rays, that changes thanks to the Sun kicking the Earth's magnetic field and such. Volcanoes spew material with relatively high radioactive content. So do coal-fired power plants. And nuclear dumps and mines.

On global average, human addition is dwarfed by the natural and its variation. It gets troublesome if it gets concentrated at some places.

_{*Lunatic*, n.
One whose delusions are out of fashion.}